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Fantaci B, Calvo B, Rodríguez JF. Modeling biological growth of human keratoconus: On the effect of tissue degradation, location and size. Comput Biol Med 2024; 180:108976. [PMID: 39116714 DOI: 10.1016/j.compbiomed.2024.108976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 07/17/2024] [Accepted: 07/30/2024] [Indexed: 08/10/2024]
Abstract
Keratoconus is a non-inflammatory bilateral disease, that usually occurs in the inferior-temporal region, where the cornea bulges out and becomes thinner, due to the gradual loss of structural organization in corneal tissue. Degenerated extracellular matrix and fibers breakage have been observed in keratoconic corneas, that may promote the progression of the pathology. While keratoconus histopathology has been widely described in literature, its etiology is still not clear. Being able to fully understand keratoconus growing process could be crucial to detect its development and improve prevention strategies. This work proposes a novel continuum-based keratoconus growth model. The proposed framework accounts for the structural changes occurring in the underlying tissue during the progression of the disease, as indicated in experiments. The developed formulation is able to replicate the typical bulging and thinning of keratoconic corneas, as well as different forms in terms of shape, as they are commonly classified in clinics (nipple, oval and globus cones). The cone that is obtained constitutes a permanent deformed state, not pressure dependent. The resulting model may help to better understand the etiology of the behavior of this disease with the aim of improving the diagnosis and the treatment of the pathology.
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Affiliation(s)
- Benedetta Fantaci
- Aragon Institute of Research Engineering (I3A), Universidad de Zaragoza, Zaragoza, Spain.
| | - Begoña Calvo
- Aragon Institute of Research Engineering (I3A), Universidad de Zaragoza, Zaragoza, Spain; Bioengineering, Biomaterials and Nanomedicine Networking Biomedical Research Centre (CIBER-BBN), Universidad de Zaragoza, Zaragoza, Spain
| | - José Félix Rodríguez
- LaBS, Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Milan, Italy
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Özelbaykal B, Kaya O, Kasım B, Birkandan T, Koçluk Y. Diagnostic ability of the corneal anterior and posterior surface area calculated by corneal modelling approach in early stage keratoconus patients. Eur J Ophthalmol 2024:11206721241272151. [PMID: 39140977 DOI: 10.1177/11206721241272151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2024]
Abstract
PURPOSE To investigate the discrimination ability of the corneal anterior and posterior surface area between patients with keratoconus stage 1 and normal individuals. METHODS In this retrospective study, 116 eyes of 116 normal individuals and 366 eyes of 366 keratoconus patients were included. Keratoconus patients were divided into six groups according to the topographic keratoconus classification of Pentacam. Anterior and posterior surface data of sagittal (SM) and elevation maps (EM) were exported from Pentacam, and human corneal models were created employing the software utilizing the PyVista module of Python programming language. The anterior and posterior corneal surface area (a-CSA and p-CSA) of SM and EM were calculated by the software ranging from central 3 to 8mm diameter. RESULTS Anterior and posterior CSA values were higher in KC patients compared to normal individuals (p < 0.001). The p-CSA for SM and EM measured at the central 3mm was higher in patients with KC-1 compared to normal eyes (p = 0.002, p = 0.005, respectively), For both maps, a-CSA and p-CSA measured at the central 4 and 5mm were higher in KC-1 compared to normal individuals (p < 0.05). The highest area under the curve (AUC) values in the diagnosis patients with KC-1 were obtained from 3mm p-CSA for SM (AUC: 0.8338), 3mm p-CSA for EM (AUC: 0.7999), 4mm p-CSA for SM (AUC: 0.8531), 4mm p-CSA for EM (AUC:0.7948), 5mm p-CSA for SM (AUC: 0.8455), 5mm p-CSA for EM (AUC:0.7614). CONCLUSION The corneal surface area as a parameter, especially for central 3, 4, and 5mm, has a discrimination ability in diagnosing keratoconus disease and distinguishes normal eyes from KC-1 eyes.
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Affiliation(s)
- Bahadır Özelbaykal
- Department of Ophthalmology, Adana City Training and Research Hospital, Adana, Turkiye
| | - Ozan Kaya
- Department of Physics Engineering, Istanbul Technical University, Istanbul, Turkiye
| | - Burcu Kasım
- Department of Ophthalmology, Adana City Training and Research Hospital, Adana, Turkiye
| | - Tolga Birkandan
- Department of Physics Engineering, Istanbul Technical University, Istanbul, Turkiye
| | - Yusuf Koçluk
- Department of Ophthalmology, Adana City Training and Research Hospital, Adana, Turkiye
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Wu Z, Zhang Y, Li Y, Yang F, Su X, Gao Y, Wei S, Li J. Correlation between Corneal Volume and Corneal Biomechanics and Corneal Volume Significance in Staging and Diagnosing Keratoconus. J Ophthalmol 2024; 2024:8422747. [PMID: 38841207 PMCID: PMC11152760 DOI: 10.1155/2024/8422747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 05/09/2024] [Accepted: 05/18/2024] [Indexed: 06/07/2024] Open
Abstract
Purpose To investigate the relationship between corneal volume (CV) at different zones and corneal biomechanics in keratoconus (KC) along with the significance of CV in diagnosing and staging KC. Methods This prospective clinical study included 456 keratoconic eyes (Group B) and 198 normal eyes (Group A). Using the topographic KC classification method, Group B was divided into subgroups based on severity (mild, moderate, and severe). The CVs of the 3 mm, 5 mm, and 7 mm zones and biomechanical parameters were obtained by Pentacam and Corvis ST. The diagnostic utility of multirange CVs at different disease stages and severity was determined using a receiver operating characteristic (ROC) curve analysis. Results The CV of the 7-mm zone had the strongest correlation with A1V, A2T, PD, DA ratio max (2 mm), DA ratio max (1 mm), ARTh, integrated radius, SPA1, and CBI (p < 0.01). The CVs of the Group B subgroups were significantly lower than those of Group A for each diameter range (p < 0.05). There were significant differences between the severe, mild, and moderate subgroups for the 3 mm zone (p < 0.05, all). The 3 mm zone CV exhibited better diagnostic ability in each group for distinguishing KC from the normal cornea (Groups A vs. B: area under the ROC curve (AUC) = 0.926, Groups A vs. B1: AUC = 0.894, Groups A vs. B2: AUC = 0.925, Groups A vs. B3: AUC = 0.953). Conclusion The CV significantly decreased in keratoconic eyes. Progressive thinning in the 3 mm zone may be a valuable measurement for detecting and staging KC. Combining the CV examination with corneal biomechanical information may effectively enhance the ability to detect KC.
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Affiliation(s)
- Zhiqing Wu
- Department of Ophthalmology, Hospital of Shaanxi Normal University, Xi'an 710004, China
| | - Yaohua Zhang
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated People's Hospital of Northwest University, Xi'an 710004, China
| | - Yong Li
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated People's Hospital of Northwest University, Xi'an 710004, China
| | - Fang Yang
- Department of Ophthalmology, Renmin Hospital, Hubei University of Medicine, Shiyan 442000, Hubei, China
| | - Xirui Su
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated People's Hospital of Northwest University, Xi'an 710004, China
| | - Yan Gao
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated People's Hospital of Northwest University, Xi'an 710004, China
| | - Shengsheng Wei
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated People's Hospital of Northwest University, Xi'an 710004, China
| | - Jing Li
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated People's Hospital of Northwest University, Xi'an 710004, China
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Huo Y, Chen X, Khan GA, Wang Y. Corneal biomechanics in early diagnosis of keratoconus using artificial intelligence. Graefes Arch Clin Exp Ophthalmol 2024; 262:1337-1349. [PMID: 37943332 DOI: 10.1007/s00417-023-06307-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 10/18/2023] [Accepted: 10/23/2023] [Indexed: 11/10/2023] Open
Abstract
Keratoconus is a blinding eye disease that affects activities of daily living; therefore, early diagnosis is crucial. Great efforts have been made toward an early diagnosis of keratoconus. Recent studies have shown that corneal biomechanics is associated with the occurrence and progression of keratoconus. Hence, detecting changes in corneal biomechanics may provide a novel strategy for early diagnosis. However, an early keratoconus diagnosis remains challenging due to the subtle and localized nature of its lesions. Artificial intelligence has been used to help address this problem. Herein, we reviewed the literature regarding three aspects of keratoconus (keratoconus, early keratoconus, and keratoconus grading) based on corneal biomechanical properties using artificial intelligence. Furthermore, we summarized the current research progress, limitations, and possible prospects.
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Affiliation(s)
- Yan Huo
- School of Medicine, Nankai University, Tianjin, China
| | - Xuan Chen
- School of Medicine, Nankai University, Tianjin, China
| | - Gauhar Ali Khan
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Yan Wang
- School of Medicine, Nankai University, Tianjin, China.
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Nankai University Affiliated Eye Hospital, 4 Gansu Road, He-ping District, Tianjin, 300020, China.
- Nankai Eye Institute, Nankai University, Tianjin, China.
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Vilares-Morgado R, Ferreira AM, Cunha AM, Moreira R, Torrão L, Neves-Cardoso P, Pinheiro-Costa J. Transepithelial Accelerated Crosslinking for Progressive Keratoconus: A Critical Analysis of Medium-Term Treatment Outcomes. Clin Ophthalmol 2024; 18:393-407. [PMID: 38348140 PMCID: PMC10860395 DOI: 10.2147/opth.s450916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 01/24/2024] [Indexed: 02/15/2024] Open
Abstract
Purpose To report the 4-year outcomes of transepithelial accelerated corneal collagen crosslinking (TE-ACXL) in the treatment of eyes with progressive keratoconus (KC). Methods Eyes of patients who underwent TE-ACXL (6mW/cm2 for 15 minutes) for progressive KC and presented 48 months of follow-up were included. Corrected distance visual acuity (CDVA), keratometry measurements (Kmax, maximum keratometry, Kmean, mean keratometry and Astg, corneal astigmatism), thinnest corneal thickness (PachyMin), and topographic, and tomographic indices (specifically the posterior radius of curvature from the 3.0 mm centered on the thinnest point of the cornea (PRC), and the D-index) were analysed preoperatively and every 12 months after TE-ACXL, up to 48 months. Progression after TE-ACXL was considered when eyes presented ≥1 criteria: (1) increase of ≥1D in Kmax or increase of ≥0.75D in Kmean or increase of ≥1D in Astg; (2) reduction of ≥0.085 mm in PRC; (3) decrease ≥5% in PachyMin. Results 41 eyes from 30 patients were included, with a mean age at crosslinking of 20.90±4.69 years. There was a significant increase in Kmean (+0.64±1.04 D, p<0.001; +0.98 ± 1.49 D, p<0.001; +1.27±2.01 D, p<0.001; +1.13±2.00 D, p=0.006) and a significant decrease in PRC throughout follow-up (-0.12±0.22, p=0.002; -0.15±0.24, p<0.001; -0.17±0.43, p=0.021; -0.16±0.43, p=0.027). PachyMin decreased significantly at 36 and 48 months (-8.50±15.93 μm, p=0.004; -7.82±18.37, p=0.033). According to our progression criteria, there was a major progression rate throughout follow-up (57.1%, 61.1%, 58.8%, and 67.9%, respectively). Surgery and follow-up were uneventful in all subjects. Eleven eyes (26.8%) required further procedures, ≥36 months after the initial TE-ACXL, due to persistent progressive disease. Conclusion TE-ACXL proved to be a safe therapeutic option for progressive KC. However, its efficacy is deemed unsatisfactory, as a notable proportion of affected eyes may continue to advance within a 4-year timeframe, necessitating additional procedures to halt the disease's course.
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Affiliation(s)
- Rodrigo Vilares-Morgado
- Department of Ophthalmology, Centro Hospitalar Universitário de São João, Porto, Portugal
- Department of Surgery and Physiology, Faculty of Medicine of Porto University, Porto, Portugal
| | - Ana Margarida Ferreira
- Department of Ophthalmology, Centro Hospitalar Universitário de São João, Porto, Portugal
- Department of Surgery and Physiology, Faculty of Medicine of Porto University, Porto, Portugal
| | - Ana Maria Cunha
- Department of Ophthalmology, Centro Hospitalar Universitário de São João, Porto, Portugal
- Department of Surgery and Physiology, Faculty of Medicine of Porto University, Porto, Portugal
| | - Raúl Moreira
- Department of Ophthalmology, Centro Hospitalar Universitário de São João, Porto, Portugal
- Department of Surgery and Physiology, Faculty of Medicine of Porto University, Porto, Portugal
| | - Luís Torrão
- Department of Ophthalmology, Centro Hospitalar Universitário de São João, Porto, Portugal
- Department of Surgery and Physiology, Faculty of Medicine of Porto University, Porto, Portugal
| | - Pedro Neves-Cardoso
- Department of Ophthalmology, Centro Hospitalar Universitário de São João, Porto, Portugal
- Department of Surgery and Physiology, Faculty of Medicine of Porto University, Porto, Portugal
| | - João Pinheiro-Costa
- Department of Ophthalmology, Centro Hospitalar Universitário de São João, Porto, Portugal
- Department of Surgery and Physiology, Faculty of Medicine of Porto University, Porto, Portugal
- Department of Biomedicine, Faculty of Medicine of Porto University, Porto, Portugal
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Gómez C, Piñero DP, Paredes M, Alió JL, Cavas F. Study of the Influence of Boundary Conditions on Corneal Deformation Based on the Finite Element Method of a Corneal Biomechanics Model. Biomimetics (Basel) 2024; 9:73. [PMID: 38392119 PMCID: PMC10886865 DOI: 10.3390/biomimetics9020073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 02/24/2024] Open
Abstract
Implementing in silico corneal biomechanical models for surgery applications can be boosted by developing patient-specific finite element models adapted to clinical requirements and optimized to reduce computational times. This research proposes a novel corneal multizone-based finite element model with octants and circumferential zones of clinical interest for material definition. The proposed model was applied to four patient-specific physiological geometries of keratoconus-affected corneas. Free-stress geometries were calculated by two iterative methods, the displacements and prestress methods, and the influence of two boundary conditions: embedded and pivoting. The results showed that the displacements, stress and strain fields differed for the stress-free geometry but were similar and strongly depended on the boundary conditions for the estimated physiological geometry when considering both iterative methods. The comparison between the embedded and pivoting boundary conditions showed bigger differences in the posterior limbus zone, which remained closer in the central zone. The computational calculation times for the stress-free geometries were evaluated. The results revealed that the computational time was prolonged with disease severity, and the displacements method was faster in all the analyzed cases. Computational times can be reduced with multicore parallel calculation, which offers the possibility of applying patient-specific finite element models in clinical applications.
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Affiliation(s)
- Carmelo Gómez
- International School of Doctorate, Technical University of Cartagena, 30202 Cartagena, Spain
| | - David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain
| | - Manuel Paredes
- ICA, Université de Toulouse, UPS, INSA, ISAE-SUPAERO, MINES-ALBI, CNRS, 3 rue Caroline Aigle, 31400 Toulouse, France
| | - Jorge L Alió
- Cornea, Cataract and Refractive Surgery Department, VISSUM, 03016 Alicante, Spain
- Division of Ophthalmology, Department of Pathology and Surgery, Faculty of Medicine, Miguel Hernández University, 03202 Alicante, Spain
| | - Francisco Cavas
- Department of Structures, Construction and Graphic Expression, Technical University of Cartagena, 30202 Cartagena, Spain
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Kapur N, Chatterjee S, Gomase SN, Khurana A, Parmar G, Sangwan VS. Preferred practice patterns for keratoconus: An e-survey among Indian cornea specialists. Indian J Ophthalmol 2024; 72:111-117. [PMID: 38131580 PMCID: PMC10841772 DOI: 10.4103/ijo.ijo_817_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 07/31/2023] [Accepted: 08/02/2023] [Indexed: 12/23/2023] Open
Abstract
PURPOSE This study aimed to report practice patterns in the management of keratoconus in India. METHODS An e-survey was conducted among members of the Cornea Society of India to assess preferred practice patterns for keratoconus. RESULTS Of the 912 members, 234 (25.7%) completed the survey. About 88.4% worked in private eye care facilities and 76.1% in cities. Of all the respondents, 91.5% had access to a Scheimpflug-based device or an Orbscan II®; 71.4% of the respondents dispensed scleral contact lenses, and 66.7% dispensed Rose K contact lenses; 92.7% of the respondents performed corneal cross-linking (CXL); and 73.1% of the respondents performed deep anterior lamellar keratoplasty (DALK). A Scheimpflug device or Orbscan II®, Rose K or scleral contact lenses, and CXL were more readily available (P < 0.05) in private eye care facilities. The diagnostic criteria for keratoconus followed by the majority of the respondents (52.1%) were increase in corneal curvature, elevation, and thickness. An increase in keratometry values greater than 0.5 or 1.0D in a 6-month to 1-year period was considered the most favored criterion for keratoconus progression. Epithelium-off, 0.1% riboflavin solution in dextran, and accelerated protocol were the more commonly reported techniques in CXL. About 77.2% of the respondents routinely performed CXL in corneas <400 microns thick. Spectacles (91.0% of the respondents) and topography-guided photorefractive keratectomy (37.6% of the respondents) were, respectively, the preferred optical and surgical methods used to improve vision. CONCLUSION While keratoconus management in India is comparable to other developed healthcare systems, the concentration of trained corneal surgeons in cities and private eyecare facilities may lead to less equitable distribution of treatment across the country.
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Affiliation(s)
- Neha Kapur
- Department of Cornea and Anterior Segment, Dr Shroff’s Charity Eye Hospital, New Delhi, India
| | - Samrat Chatterjee
- Department of Cornea and Anterior Segment, MGM Eye Institute, Raipur, Chhattisgarh, India
| | - Sharad Nivrutti Gomase
- Department of Cornea and Anterior Segment, MGM Eye Institute, Raipur, Chhattisgarh, India
| | - Ashi Khurana
- Department of Cornea and Anterior Segment, CL Gupta Eye Institute, Moradabad, Uttar Pradesh, India
| | - Gautam Parmar
- Department of Cornea and Refractive Surgery, Sadguru Netra Chikitsalaya, Chitrakoot, Madhya Pradesh, India
| | - Virendra Singh Sangwan
- Department of Cornea and Anterior Segment, Dr Shroff’s Charity Eye Hospital, New Delhi, India
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Miyakoshi A, Hayashi A, Oiwake T. Parameters of a basic ophthalmic examination that can ensure proper timing of corneal crosslinking in patients with keratoconus. Int Ophthalmol 2023; 43:4797-4802. [PMID: 37910298 DOI: 10.1007/s10792-023-02881-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 09/27/2023] [Indexed: 11/03/2023]
Abstract
BACKGROUND By the time patients with keratoconus are referred to specialists for treatment, the disease-related thinning of their corneas has already made them ineligible (< 400 μm) for corneal crosslinking (CXL). PURPOSE To find basic ophthalmic examination parameters that can ensure proper timing of referral for CXL. METHODS We reviewed cases referred to Toyama University Hospital for the treatment of keratoconus from August 2011 to May 2021 to identify the frequency of contraindication due to minimal corneal thickness (MCT) < 400 μm at first visit. We performed a receiver operator characteristic (ROC) analysis of basic exam parameters (uncorrected distance visual acuity, corrected distance visual acuity, corrected distance visual acuity with hard contact lens, sphericity, cylindricity, and/or corneal astigmatism) potentially predicting eligibility for CXL. For those with an area under the curve (AUC) > 0.8, we determined cut-off values and calculated sensitivity and specificity. RESULTS Analyses included 66 eyes of 38 Japanese patients aged 25.0 ± 7.1 yrs (range 12-38 yrs) (56 male eyes and 10 female eyes). Thirty percent of the patients had an MCT < 400 μm. The AUC for uncorrected distance visual acuity (UCDVA) was 0.85. A cut-off value of 1.22 (converted to decimal visual acuity: ≥ 0.06) yielded 87% sensitivity and 75% specificity. The AUC for corrected distance visual acuity (CDVA) was 0.90. A cut-off of 0.52 (converted to decimal visual acuity: ≥ 0.3) yielded 89% sensitivity and 75% specificity. CONCLUSIONS It is advisable to refer patients with keratoconus to a specialized facility for CXL when either of the following conditions is present: (i) UCDVA (decimal visual acuity) ≥ 0.06 or (ii) CDVA (decimal visual acuity) ≥ 0.3.
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Affiliation(s)
- Akio Miyakoshi
- Department of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama-Shi, 930-0194, Japan.
| | - Atsushi Hayashi
- Department of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama-Shi, 930-0194, Japan
| | - Toshihiko Oiwake
- Department of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama-Shi, 930-0194, Japan
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Kim K, Koh K, Lee S, Lee Y. Diagnostic Validation of the Screening Corneal Objective Risk of Ectasia Analyzer Evaluated by Swept Source Optical Coherence Tomography for Keratoconus in an Asian Population. Bioengineering (Basel) 2023; 10:1335. [PMID: 38002459 PMCID: PMC10669067 DOI: 10.3390/bioengineering10111335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/27/2023] [Accepted: 11/16/2023] [Indexed: 11/26/2023] Open
Abstract
We aimed to investigate the diagnostic accuracy of Screening Corneal Objective Risk of Ectasia (SCORE) Analyzer software using ANTERION, a swept-source optical coherence tomography device, for keratoconus diagnosis in an Asian population. A total of 151 eyes of 151 patients were included in this retrospective study as follows: 60, 45, and 46 keratoconus, keratoconus suspects, and normal control eyes, respectively. Parameters in the SCORE calculation, including six indices, were compared for the three groups. The receiver operating characteristic curve analysis and cut-off value were estimated to assess the diagnostic ability to differentiate keratoconus and keratoconus suspect eyes from the normal group. The SCORE value and six indices were significantly correlated-"AntK max" (R = 0.864), "AntK oppoK" (R = 0.866), "Ant inf supK" (R = 0.943), "Ant irre 3mm" (R = 0.741), "post elevation at the thinnest point" (R = 0.943), and "minimum corneal thickness" (R = -0.750). The SCORE value showed high explanatory power (98.1%), sensitivity of 81.9%, and specificity of 78.3% (cut-off value: 0.25) in diagnosing normal eyes from the keratoconus suspect and keratoconus eyes. The SCORE Analyzer was found to be valid and consistent, showing good sensitivity and specificity for keratoconus detection in an Asian population.
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Affiliation(s)
| | - Kyungmin Koh
- Kim’s Eye Hospital, Seoul 07301, Republic of Korea
| | - Seongjun Lee
- Nuri Eye Hospital, Daejeon 35233, Republic of Korea
| | - Yongwoo Lee
- Departement of Ophthalmology, Kangwon National University Hopsital, Kangwon National University School of Medicine, Chuncheon, Gangwon 24289, Republic of Korea
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Vandevenne MM, Favuzza E, Veta M, Lucenteforte E, Berendschot TT, Mencucci R, Nuijts RM, Virgili G, Dickman MM. Artificial intelligence for detecting keratoconus. Cochrane Database Syst Rev 2023; 11:CD014911. [PMID: 37965960 PMCID: PMC10646985 DOI: 10.1002/14651858.cd014911.pub2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
BACKGROUND Keratoconus remains difficult to diagnose, especially in the early stages. It is a progressive disorder of the cornea that starts at a young age. Diagnosis is based on clinical examination and corneal imaging; though in the early stages, when there are no clinical signs, diagnosis depends on the interpretation of corneal imaging (e.g. topography and tomography) by trained cornea specialists. Using artificial intelligence (AI) to analyse the corneal images and detect cases of keratoconus could help prevent visual acuity loss and even corneal transplantation. However, a missed diagnosis in people seeking refractive surgery could lead to weakening of the cornea and keratoconus-like ectasia. There is a need for a reliable overview of the accuracy of AI for detecting keratoconus and the applicability of this automated method to the clinical setting. OBJECTIVES To assess the diagnostic accuracy of artificial intelligence (AI) algorithms for detecting keratoconus in people presenting with refractive errors, especially those whose vision can no longer be fully corrected with glasses, those seeking corneal refractive surgery, and those suspected of having keratoconus. AI could help ophthalmologists, optometrists, and other eye care professionals to make decisions on referral to cornea specialists. Secondary objectives To assess the following potential causes of heterogeneity in diagnostic performance across studies. • Different AI algorithms (e.g. neural networks, decision trees, support vector machines) • Index test methodology (preprocessing techniques, core AI method, and postprocessing techniques) • Sources of input to train algorithms (topography and tomography images from Placido disc system, Scheimpflug system, slit-scanning system, or optical coherence tomography (OCT); number of training and testing cases/images; label/endpoint variable used for training) • Study setting • Study design • Ethnicity, or geographic area as its proxy • Different index test positivity criteria provided by the topography or tomography device • Reference standard, topography or tomography, one or two cornea specialists • Definition of keratoconus • Mean age of participants • Recruitment of participants • Severity of keratoconus (clinically manifest or subclinical) SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register), Ovid MEDLINE, Ovid Embase, OpenGrey, the ISRCTN registry, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP). There were no date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 29 November 2022. SELECTION CRITERIA We included cross-sectional and diagnostic case-control studies that investigated AI for the diagnosis of keratoconus using topography, tomography, or both. We included studies that diagnosed manifest keratoconus, subclinical keratoconus, or both. The reference standard was the interpretation of topography or tomography images by at least two cornea specialists. DATA COLLECTION AND ANALYSIS Two review authors independently extracted the study data and assessed the quality of studies using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. When an article contained multiple AI algorithms, we selected the algorithm with the highest Youden's index. We assessed the certainty of evidence using the GRADE approach. MAIN RESULTS We included 63 studies, published between 1994 and 2022, that developed and investigated the accuracy of AI for the diagnosis of keratoconus. There were three different units of analysis in the studies: eyes, participants, and images. Forty-four studies analysed 23,771 eyes, four studies analysed 3843 participants, and 15 studies analysed 38,832 images. Fifty-four articles evaluated the detection of manifest keratoconus, defined as a cornea that showed any clinical sign of keratoconus. The accuracy of AI seems almost perfect, with a summary sensitivity of 98.6% (95% confidence interval (CI) 97.6% to 99.1%) and a summary specificity of 98.3% (95% CI 97.4% to 98.9%). However, accuracy varied across studies and the certainty of the evidence was low. Twenty-eight articles evaluated the detection of subclinical keratoconus, although the definition of subclinical varied. We grouped subclinical keratoconus, forme fruste, and very asymmetrical eyes together. The tests showed good accuracy, with a summary sensitivity of 90.0% (95% CI 84.5% to 93.8%) and a summary specificity of 95.5% (95% CI 91.9% to 97.5%). However, the certainty of the evidence was very low for sensitivity and low for specificity. In both groups, we graded most studies at high risk of bias, with high applicability concerns, in the domain of patient selection, since most were case-control studies. Moreover, we graded the certainty of evidence as low to very low due to selection bias, inconsistency, and imprecision. We could not explain the heterogeneity between the studies. The sensitivity analyses based on study design, AI algorithm, imaging technique (topography versus tomography), and data source (parameters versus images) showed no differences in the results. AUTHORS' CONCLUSIONS AI appears to be a promising triage tool in ophthalmologic practice for diagnosing keratoconus. Test accuracy was very high for manifest keratoconus and slightly lower for subclinical keratoconus, indicating a higher chance of missing a diagnosis in people without clinical signs. This could lead to progression of keratoconus or an erroneous indication for refractive surgery, which would worsen the disease. We are unable to draw clear and reliable conclusions due to the high risk of bias, the unexplained heterogeneity of the results, and high applicability concerns, all of which reduced our confidence in the evidence. Greater standardization in future research would increase the quality of studies and improve comparability between studies.
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Affiliation(s)
- Magali Ms Vandevenne
- University Eye Clinic Maastricht, Maastricht University Medical Center (MUMC+), Maastricht, Netherlands
| | - Eleonora Favuzza
- Department of Neurosciences, Psychology, Pharmacology and Child Health, University of Florence, Florence, Italy
| | - Mitko Veta
- Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
| | - Ersilia Lucenteforte
- Department of Statistics, Computer Science and Applications «G. Parenti», University of Florence, Florence, Italy
| | - Tos Tjm Berendschot
- University Eye Clinic Maastricht, Maastricht University Medical Center (MUMC+), Maastricht, Netherlands
| | - Rita Mencucci
- Department of Neurosciences, Psychology, Pharmacology and Child Health, University of Florence, Florence, Italy
| | - Rudy Mma Nuijts
- University Eye Clinic Maastricht, Maastricht University Medical Center (MUMC+), Maastricht, Netherlands
| | - Gianni Virgili
- Department of Neurosciences, Psychology, Pharmacology and Child Health, University of Florence, Florence, Italy
- Queen's University Belfast, Belfast, UK
| | - Mor M Dickman
- University Eye Clinic Maastricht, Maastricht University Medical Center (MUMC+), Maastricht, Netherlands
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11
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Han X, Shen Y, Gu D, Zhang X, Sun L, Chen Z, Zhou X. Prediction of posterior elevation stability in keratoconus. Front Bioeng Biotechnol 2023; 11:1288134. [PMID: 38026865 PMCID: PMC10670491 DOI: 10.3389/fbioe.2023.1288134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 10/25/2023] [Indexed: 12/01/2023] Open
Abstract
Purpose: This study aimed to investigate the features of progressive keratoconus by means of machine learning. Methods: In total, 163 eyes from 127 patients with at least 3 examination records were enrolled in this study. Pentacam HR was used to measure corneal topography. Steepest meridian keratometry (K1), flattest meridian keratometry (K2), steepest anterior keratometry (Kmax), central corneal thickness (CCT), thinnest corneal thickness (TCT), anterior radius of cornea (ARC), posterior elevation (PE), index of surface variation (ISV), and index of height deviation (IHD) were input for analysis. Support vector machine (SVM) and logistic regression analysis were applied to construct prediction models. Results: Age, PE, and IHD showed statistically significant differences as the follow-up period extended. K2, PE, and ARC were selected for model construction. Logistic regression analysis presented a mean area under the curve (AUC) score of 0.780, while SVM presented a mean AUC of 0.659. The prediction sensitivity of SVM was 52.9%, and specificity was 79.0%. Conclusion: It is feasible to use machine learning to predict the progression and prognosis of keratoconus. Posterior elevation exhibits a sensitive prediction effect.
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Affiliation(s)
- Xiaosong Han
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Key Laboratory of Myopia, Fudan University, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Yang Shen
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Key Laboratory of Myopia, Fudan University, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Dantong Gu
- Clinical Research and Achievement Translation Center, Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Xiaoyu Zhang
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Key Laboratory of Myopia, Fudan University, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Ling Sun
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Key Laboratory of Myopia, Fudan University, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Zhi Chen
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Key Laboratory of Myopia, Fudan University, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Xingtao Zhou
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Key Laboratory of Myopia, Fudan University, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
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12
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Niazi S, Jiménez-García M, Findl O, Gatzioufas Z, Doroodgar F, Shahriari MH, Javadi MA. Keratoconus Diagnosis: From Fundamentals to Artificial Intelligence: A Systematic Narrative Review. Diagnostics (Basel) 2023; 13:2715. [PMID: 37627975 PMCID: PMC10453081 DOI: 10.3390/diagnostics13162715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/21/2023] [Accepted: 07/26/2023] [Indexed: 08/27/2023] Open
Abstract
The remarkable recent advances in managing keratoconus, the most common corneal ectasia, encouraged researchers to conduct further studies on the disease. Despite the abundance of information about keratoconus, debates persist regarding the detection of mild cases. Early detection plays a crucial role in facilitating less invasive treatments. This review encompasses corneal data ranging from the basic sciences to the application of artificial intelligence in keratoconus patients. Diagnostic systems utilize automated decision trees, support vector machines, and various types of neural networks, incorporating input from various corneal imaging equipment. Although the integration of artificial intelligence techniques into corneal imaging devices may take time, their popularity in clinical practice is increasing. Most of the studies reviewed herein demonstrate a high discriminatory power between normal and keratoconus cases, with a relatively lower discriminatory power for subclinical keratoconus.
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Affiliation(s)
- Sana Niazi
- Translational Ophthalmology Research Center, Tehran University of Medical Sciences, Tehran P.O. Box 1336616351, Iran;
| | - Marta Jiménez-García
- Department of Ophthalmology, Antwerp University Hospital (UZA), 2650 Edegem, Belgium
- Department of Medicine and Health Sciences, University of Antwerp, 2000 Antwerp, Belgium
| | - Oliver Findl
- Department of Ophthalmology, Vienna Institute for Research in Ocular Surgery (VIROS), Hanusch Hospital, 1140 Vienna, Austria
| | - Zisis Gatzioufas
- Department of Ophthalmology, University Hospital Basel, 4031 Basel, Switzerland;
| | - Farideh Doroodgar
- Translational Ophthalmology Research Center, Tehran University of Medical Sciences, Tehran P.O. Box 1336616351, Iran;
- Negah Aref Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran P.O. Box 1544914599, Iran
| | - Mohammad Hasan Shahriari
- Department of Health Information Technology and Management, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran P.O. Box 1971653313, Iran
| | - Mohammad Ali Javadi
- Ophthalmic Research Center, Labbafinezhad Hospital, Shahid Beheshti University of Medical Sciences, Tehran P.O. Box 19395-4741, Iran
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Ortiz-Toquero S, Fuente C, Auladell C, Arnalich-Montiel F. Influence of Keratoconus Severity on Detecting True Progression with Scheimpflug Imaging and Anterior Segment Optical Coherence Tomography. Life (Basel) 2023; 13:1474. [PMID: 37511849 PMCID: PMC10382025 DOI: 10.3390/life13071474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/17/2023] [Accepted: 06/28/2023] [Indexed: 07/30/2023] Open
Abstract
To determine consistent change over time in keratoconus disease, it is necessary to establish progression cut-off values based on intersession variability of the device used to monitor the cornea. The aim of this study was to analyze the accuracy of corneal parameters using Scheimpflug tomography and anterior segment optical coherence tomography in healthy and keratoconic eyes of varying severity to determine the cut-off values that indicate real progression. Three repeated measurements of each cornea of healthy (20 eyes) and keratoconic eyes (mild = 16, moderate = 25 and severe = 20) were recorded using Pentacam and Casia SS-1000 devices, which were repeated 2-3 weeks later. K1, K2, maximal anterior and posterior keratometry, and corneal thickness at the thinnest location (TCT) were collected. The accuracy was excellent with both devices; however, the Casia device presented better repeatability and reproducibility in all parameters in all groups compared to the Pentacam. The cut-off of the Pentacam and Casia in the mild stage were lower (K1 = 0.50 and 0.37 D; K2 = 0.51 and 0.37 D; Kmax-A = 1.24 and 0.65 D; Kmax-P = 0.38 and 0.17 D; TCT = 19.64 and 11.19 µm) than that of the severe stage (K1 = 1.09 and 0.88 D; K2 = 1.41 and 0.87 D; Kmax-A = 2.74 and 2.15 D; Kmax-P = 0.82 and 0.22 D; TCT = 28.68 and 14.83 µm). These results show that the greater the keratoconus severity, the greater the change that must occur for it to be considered real.
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Affiliation(s)
- Sara Ortiz-Toquero
- Department of Ophthalmology, Ramón y Cajal University Hospital, Carretera de Colmenar Viejo Km 9, 100, 28034 Madrid, Spain
- Optometry Research Group, IOBA-Eye Institute, Department of Theoretical Physics, Atomic and Optics, University of Valladolid, 47011 Valladolid, Spain
| | - Carlota Fuente
- Department of Ophthalmology, Ramón y Cajal University Hospital, Carretera de Colmenar Viejo Km 9, 100, 28034 Madrid, Spain
| | - Clara Auladell
- Department of Ophthalmology, Ramón y Cajal University Hospital, Carretera de Colmenar Viejo Km 9, 100, 28034 Madrid, Spain
| | - Francisco Arnalich-Montiel
- Department of Ophthalmology, Ramón y Cajal University Hospital, Carretera de Colmenar Viejo Km 9, 100, 28034 Madrid, Spain
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14
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Achiron A, Yavnieli R, Tiosano A, Elbaz U, Nahum Y, Livny E, Bahar I. ABCD progression display for keratoconus progression: a sensitivity-specificity study. Eye (Lond) 2023; 37:1566-1570. [PMID: 35869390 PMCID: PMC10220054 DOI: 10.1038/s41433-022-02183-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 07/05/2022] [Accepted: 07/11/2022] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVE To evaluate the sensitivity and specificity of the ABCD progression display for keratoconus progression. METHODS Data was collected from patients that underwent at least two Pentacam assessments 6 months apart. Sensitivity and specificity were calculated for the ABCD progression display. Progression was defined by criterion 1: change in two ABCD parameters above 80% confidence interval (CI) or criterion 2: change in one ABCD parameter above 95%CI. Receiver operating characteristic analysis compared the area under the curve (AUC) of all ABCD parameter combinations. RESULTS Thirty eyes were evaluated over a median time of 10.3 months. Progression by criterion 1 resulted in a sensitivity of 61.9% and specificity of 88.9%. Progression by criterion 2 resulted in higher sensitivity (80.9%) and specificity (100%). Pairwise comparisons of the ROC curves show that the AUC achieved by criterion 2 was significantly higher than criterion 1 (0.905 vs. 0.754, p = 0.0332). Evaluation of all ABCD combinations with a significant change of 80% or 95% CI did not show superiority over criterion 1 or 2 regarding progression detection. The D parameter had a very low AUC (0.5-0.556). CONCLUSIONS The ABCD progression display can assess keratoconus progression with high sensitivity and specificity, thus assisting the patients' decision-making process. The D parameter did not contribute to the sensitivity or specificity of this classification.
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Affiliation(s)
- Asaf Achiron
- Department of Ophthalmology, Rabin Medical Center, Petah Tikva, Israel.
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Roy Yavnieli
- Department of Ophthalmology, Rabin Medical Center, Petah Tikva, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Alon Tiosano
- Department of Ophthalmology, Rabin Medical Center, Petah Tikva, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Uri Elbaz
- Department of Ophthalmology, Rabin Medical Center, Petah Tikva, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yoav Nahum
- Department of Ophthalmology, Rabin Medical Center, Petah Tikva, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Eitan Livny
- Department of Ophthalmology, Rabin Medical Center, Petah Tikva, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Irit Bahar
- Department of Ophthalmology, Rabin Medical Center, Petah Tikva, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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15
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Lan G, Twa MD, Song C, Feng J, Huang Y, Xu J, Qin J, An L, Wei X. In vivo corneal elastography: A topical review of challenges and opportunities. Comput Struct Biotechnol J 2023; 21:2664-2687. [PMID: 37181662 PMCID: PMC10173410 DOI: 10.1016/j.csbj.2023.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/07/2023] [Accepted: 04/12/2023] [Indexed: 05/16/2023] Open
Abstract
Clinical measurement of corneal biomechanics can aid in the early diagnosis, progression tracking, and treatment evaluation of ocular diseases. Over the past two decades, interdisciplinary collaborations between investigators in optical engineering, analytical biomechanical modeling, and clinical research has expanded our knowledge of corneal biomechanics. These advances have led to innovations in testing methods (ex vivo, and recently, in vivo) across multiple spatial and strain scales. However, in vivo measurement of corneal biomechanics remains a long-standing challenge and is currently an active area of research. Here, we review the existing and emerging approaches for in vivo corneal biomechanics evaluation, which include corneal applanation methods, such as ocular response analyzer (ORA) and corneal visualization Scheimpflug technology (Corvis ST), Brillouin microscopy, and elastography methods, and the emerging field of optical coherence elastography (OCE). We describe the fundamental concepts, analytical methods, and current clinical status for each of these methods. Finally, we discuss open questions for the current state of in vivo biomechanics assessment techniques and requirements for wider use that will further broaden our understanding of corneal biomechanics for the detection and management of ocular diseases, and improve the safety and efficacy of future clinical practice.
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Affiliation(s)
- Gongpu Lan
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Michael D. Twa
- College of Optometry, University of Houston, Houston, TX 77204, United States
| | - Chengjin Song
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
| | - JinPing Feng
- Institute of Engineering and Technology, Hubei University of Science and Technology, Xianning, Hubei 437100, China
| | - Yanping Huang
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Jingjiang Xu
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Jia Qin
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Lin An
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Xunbin Wei
- Biomedical Engineering Department, Peking University, Beijing 100081, China
- International Cancer Institute, Peking University, Beijing 100191, China
- Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China
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16
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Decrease in Tear Film Lipid Layer Thickness in Patients with Keratoconus. J Clin Med 2022; 11:jcm11185252. [PMID: 36142899 PMCID: PMC9503260 DOI: 10.3390/jcm11185252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/01/2022] [Accepted: 09/04/2022] [Indexed: 11/17/2022] Open
Abstract
Keratoconus (KC) is a progressive corneal disorder characterized by thinning and protrusion, mostly of the inferotemporal and central corneal regions. Dysfunction of the meibomian gland, the excretions of which form the lipid layer of the tear film, has been reported to be associated with KC. Thus, this manuscript investigates the correlation among lipid layer thickness (LLT), partial blink rate (PBR), and KC of different degrees. This retrospective study included 54 patients and 24 healthy controls. The anterior corneal curvature, LLT, and PBR were taken from the unilateral eye of all 78 participants. The difference in those ocular parameters between the moderate and severe groups and the control group is significant. No significant association was found between anterior corneal curvature and LLT (r = −0.2, p = 0.15) across all the patients. However, there was a significant negative correlation between anterior corneal curvature and LLT in moderate (r = −0.6, p < 0.05) and severe (r = −0.7, p < 0.05) keratoconus cases. The results also show a significant negative correlation between anterior corneal curvature and PBR (r = −0.41, p < 0.05). Therefore, we conclude that the severity of keratoconus is associated with the thinning of LLT and the reduction of PBR. This may relate to a further epithelial abnormality with the reduced protection of tear film from the air, leading to the release of proteolytic enzymes that degrade stromal collagen and weaken the cornea.
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17
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Gao HB, Pan ZG, Shen MX, Lu F, Li H, Zhang XQ. KeratoScreen: Early Keratoconus Classification With Zernike Polynomial Using Deep Learning. Cornea 2022; 41:1158-1165. [PMID: 35543584 DOI: 10.1097/ico.0000000000003038] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 02/16/2022] [Indexed: 12/13/2022]
Abstract
PURPOSE We aimed to investigate the usefulness of Zernike coefficients (ZCs) for distinguishing subclinical keratoconus (KC) from normal corneas and to evaluate the goodness of detection of the entire corneal topography and tomography characteristics with ZCs as a screening feature input set of artificial neural networks. METHODS This retrospective study was conducted at the Affiliated Eye Hospital of Wenzhou Medical University, China. A total of 208 patients (1040 corneal topography images) were evaluated. Data were collected between 2012 and 2018 using the Pentacam system and analyzed from February 2019 to December 2021. An artificial neural network (KeratoScreen) was trained using a data set of ZCs generated from corneal topography and tomography. Each image was previously assigned to 3 groups: normal (70 eyes; average age, 28.7 ± 2.6 years), subclinical KC (48 eyes; average age, 24.6 ± 5.7 years), and KC (90 eyes; average age, 25.9 ± 5.4 years). The data set was randomly split into 70% for training and 30% for testing. We evaluated the precision of screening symptoms and examined the discriminative capability of several combinations of the input set and nodes. RESULTS The best results were achieved using ZCs generated from corneal thickness as an input parameter, determining the 3 categories of clinical classification for each subject. The sensitivity and precision rates were 93.9% and 96.1% in subclinical KC cases and 97.6% and 95.1% in KC cases, respectively. CONCLUSIONS Deep learning algorithms based on ZCs could be used to screen for early KC and for other corneal ectasia during preoperative screening for corneal refractive surgery.
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Affiliation(s)
- He-Bei Gao
- Division of Health Sciences, Hangzhou Normal University, Hangzhou, China
- Department of Information, Wenzhou Polytechnic, Wenzhou, China
| | - Zhi-Geng Pan
- School of Artificial Intelligence, Nanjing University of Information Science & Technology, Nanjing, China
| | - Mei-Xiao Shen
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China ; and
| | - Fan Lu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China ; and
| | - Hong Li
- College of Computer Science and Artificial Intelligence, Wenzhou University, Wenzhou, China
| | - Xiao-Qin Zhang
- College of Computer Science and Artificial Intelligence, Wenzhou University, Wenzhou, China
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18
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Kim KY, Lee S, Jeon YJ, Min JS. Anterior segment characteristics in normal and keratoconus eyes evaluated with a new type of swept-source optical coherence tomography. PLoS One 2022; 17:e0274071. [PMID: 36048835 PMCID: PMC9436129 DOI: 10.1371/journal.pone.0274071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 08/21/2022] [Indexed: 12/04/2022] Open
Abstract
PURPOSE This study aimed to evaluate and compare the discriminating ability of corneal elevation maps generated using a swept-source optical coherence tomography (SS-OCT) (SS-OCT ANTERION, Heidelberg Engineering, Heidelberg, Germany), which was estimated with different reference surfaces, to distinguish normal corneas from those with keratoconus and keratoconus suspect. METHODS A total of 126 eyes of patients, which comprised 43, 37, and 46 keratoconus, keratoconus suspects, and normal controls, respectively, were included in this study. The anterior and posterior elevations at the thinnest point under the best-fit sphere (BFS) and toric-ellipsoid (BFT), respectively, and other corneal parameters were measured using the SS-OCT. In addition, the receiver operating characteristic (ROC) curve analysis and cut-off value were calculated to evaluate the diagnostic ability of the corneal elevation values in differentiating keratoconus and keratoconus suspects from normal eyes. RESULTS The mean total keratometric and corneal elevation values were significantly higher in the keratoconus group than in the other groups. Pachymetric parameters exhibited the lowest values for keratoconus. In addition, ROC curve analyses showed a high accuracy of the thinnest point anterior and posterior BFT for both keratoconus and keratoconus suspects and normal controls (area under the ROC were 0.969 and 0.961, respectively). Furthermore, the optimal cut-off point of the posterior elevation at the thinnest point under BFT was 16.44 μm (sensitivity and specificity of 86% and 98%, respectively) for differentiating keratoconus from normal and keratoconus suspect eyes. CONCLUSIONS The elevation map using the BFS and BFT references measured with the anterior segment SS-OCT is considered an effective indicator for keratoconus diagnosis. Therefore, the anterior segment SS-OCT can effectively differentiate keratoconus from suspected keratoconus and normal corneas by measuring parameters such as posterior and anterior elevations, pachymetry, and keratometry.
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Xu Z, Feng R, Jin X, Hu H, Ni S, Xu W, Zheng X, Wu J, Yao K. Evaluation of artificial intelligence models for the detection of asymmetric keratoconus eyes using Scheimpflug tomography. Clin Exp Ophthalmol 2022; 50:714-723. [PMID: 35704615 DOI: 10.1111/ceo.14126] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 05/26/2022] [Accepted: 06/11/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND To evaluate artificial intelligence (AI) models based on objective indices and raw corneal data from the Scheimpflug Pentacam HR system (OCULUS Optikgeräte GmbH, Wetzlar, Germany) for the detection of clinically unaffected eyes in patients with asymmetric keratoconus (AKC) eyes. METHODS A total of 1108 eyes of 1108 patients were enrolled, including 430 eyes from normal control subjects, 231 clinically unaffected eyes from patients with AKC, and 447 eyes from keratoconus (KC) patients. Eyes were divided into a training set (664 eyes), a test set (222 eyes) and a validation set (222 eyes). AI models were built based on objective indices (XGBoost, LGBM, LR and RF) and entire corneal raw data (KerNet). The discriminating performances of the AI models were evaluated by accuracy and the area under the ROC curve (AUC). RESULTS The KerNet model showed great overall discriminating power in the test (accuracy = 94.67%, AUC = 0.985) and validation (accuracy = 94.12%, AUC = 0.990) sets, which were higher than the index-derived AI models (accuracy = 84.02%-86.98%, AUC = 0.944-0.968). In the test set, the KerNet model demonstrated good diagnostic power for the AKC group (accuracy = 95.24%, AUC = 0.984). The validation set also proved that the KerNet model was useful for AKC group diagnosis (accuracy = 94.12%, AUC = 0.983). CONCLUSIONS KerNet outperformed all the index-derived AI models. Based on the raw data of the entire cornea, KerNet was helpful for distinguishing clinically unaffected eyes in patients with AKC from normal eyes.
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Affiliation(s)
- Zhe Xu
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ruiwei Feng
- College of Computer Science and Technology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiuming Jin
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Heping Hu
- College of Computer Science and Technology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Shuang Ni
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Wen Xu
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiangshang Zheng
- College of Computer Science and Technology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jian Wu
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.,School of Public Health, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ke Yao
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
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Achiron A, Yavnieli R, Olshaker H, Levinger E, Tuuminen R, Livny E, Elbaz U, Bahar I, Nahum Y. Validation of the multi-metric D-index change in the assessment of keratoconus progression. Int Ophthalmol 2022; 42:2665-2671. [PMID: 35381894 DOI: 10.1007/s10792-022-02255-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 03/12/2022] [Indexed: 11/29/2022]
Abstract
PURPOSE To validate the effectiveness of the multi-metric D-index by Pentacam in detecting keratoconus (KC) progression. MATERIALS AND METHODS This was a retrospective study of KC patients at the Rabin Medical Center, Petah Tikva, Israel, during 2016-2018 with at least two corneal tomography examinations six months apart. Agreement between clinical diagnosis of progression (1.5D increase in mean keratometric value, 1D increase in Kmax, a 5% decrease in central corneal thickness (CCT), worsening of visual acuity by more than one line, or deterioration of manifest corneal astigmatism > 1.5D) and the D-index was evaluated. Receiver operating characteristic (ROC) analysis was used to find the D-index's optimal cutoff value to show progression. RESULTS We included KC eyes in the stable group (N = 7) and the progression group (N = 54). Patient demographics and tomographic parameters at baseline were similar between the groups. The D-index change was significantly higher in the progression group than in the stable group (median + 1 and 0.0, respectively, p = 0.024). Based on the ROC analysis, the optimal D-index cutoff change within at least six months was 0.32 (59.3% sensitivity and 100% specificity (area under the curve [AUC] = 0.771, Youden = 0.592). Subjects with a D-index change above this value had a 21.1-fold increase in odds for corneal ectasia progression requiring CXL (OR: 21.1, 95%CI 1.17-398.8, p = 0.038). CONCLUSION The multi-metric D-index can serve as a clinically feasible parameter to detect KC progression and guide patients' referral for further interventions.
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Affiliation(s)
- Asaf Achiron
- Department of Ophthalmology, Rabin Medical Center, 39 Ze'ev Jabotinsky St., 4941492, Petah-Tikva, Israel. .,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Roy Yavnieli
- Department of Ophthalmology, Rabin Medical Center, 39 Ze'ev Jabotinsky St., 4941492, Petah-Tikva, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hagar Olshaker
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Ophthalmology, Sackler Faculty of Medicine, Tel Aviv Medical Center, Tel Aviv, Israel
| | - Eliya Levinger
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Ophthalmology, Sackler Faculty of Medicine, Tel Aviv Medical Center, Tel Aviv, Israel
| | - Raimo Tuuminen
- Department of Ophthalmology, Kymenlaakso Central Hospital, Kotka, Finland.,Helsinki Retina Research Group, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Eitan Livny
- Department of Ophthalmology, Rabin Medical Center, 39 Ze'ev Jabotinsky St., 4941492, Petah-Tikva, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Uri Elbaz
- Department of Ophthalmology, Rabin Medical Center, 39 Ze'ev Jabotinsky St., 4941492, Petah-Tikva, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Irit Bahar
- Department of Ophthalmology, Rabin Medical Center, 39 Ze'ev Jabotinsky St., 4941492, Petah-Tikva, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yoav Nahum
- Department of Ophthalmology, Rabin Medical Center, 39 Ze'ev Jabotinsky St., 4941492, Petah-Tikva, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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21
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Neustein RF, Lenhart PD. Detecting Keratoconus: Feasibility and Findings in Three Pediatric Risk Groups. J Pediatr Ophthalmol Strabismus 2022; 59:94-101. [PMID: 34928766 DOI: 10.3928/01913913-20210802-01] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To investigate the utility of three corneal screening devices in three groups of children. METHODS This was a prospective study of patients with Trisomy 21 (group 1), patients with a first-degree relative with keratoconus (group 2), and control patients (group 3). Informed consent was obtained before testing with the Pentacam (Oculus Optikgeräte GmbH), Orbscan (Orbscan, Inc), and Ocular Response Analyzer (ORA) (Ametek Reichart Technologies). The ability to complete tests, the quality of results, and the corneal parameters obtained for each eye were recorded. A one-way analysis of variance test was used to compare the results between the three groups. RESULTS Fifty-four patients aged from 7 to 17 years (mean: 11.74 years) were enrolled between July 2014 and July 2016. The number of patients and the percentage of tests completed for groups 1, 2, and 3 were 12 (55%), 21 (87%), and 21 (88%), respectively. The Pentacam values by group were central corneal thickness of 524, 543, and 542 µm (P = .36); thinnest point of 498, 536, and 534 µm (P = .03); corneal front mean keratometry of 44.9, 43.2, and 43.2 (P = .01); and quality score of 1.42, 0.22, and 0.04 (P < .0001), respectively. Orbscan values by group were central corneal thickness of 493, 551, and 550 µm (P = .01) and thinnest point of 451, 536, and 538 µm (P < .0001), respectively. ORA values by group were corneal hysteresis of 10.6, 12.1, and 11.6 (P = .124); corneal resistance factor of 9.9, 11.8, and 11.6 (P = .03); and waveform score of 5.6, 7.6, and 7.3 (P < .0001), respectively. CONCLUSIONS Patients in group 1 completed fewer tests reliably and had thinner corneas and lower corneal resistance factors than patients in groups 2 and 3. Corneal tests used to evaluate adults for keratoconus may not be reliable for the evaluation of certain high-risk pediatric patients. [J Pediatr Ophthalmol Strabismus. 2022;59(2):94-101.].
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22
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Santodomingo-Rubido J, Carracedo G, Suzaki A, Villa-Collar C, Vincent SJ, Wolffsohn JS. Keratoconus: An updated review. Cont Lens Anterior Eye 2022; 45:101559. [PMID: 34991971 DOI: 10.1016/j.clae.2021.101559] [Citation(s) in RCA: 201] [Impact Index Per Article: 100.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 11/23/2021] [Accepted: 12/12/2021] [Indexed: 02/06/2023]
Abstract
Keratoconus is a bilateral and asymmetric disease which results in progressive thinning and steeping of the cornea leading to irregular astigmatism and decreased visual acuity. Traditionally, the condition has been described as a noninflammatory disease; however, more recently it has been associated with ocular inflammation. Keratoconus normally develops in the second and third decades of life and progresses until the fourth decade. The condition affects all ethnicities and both sexes. The prevalence and incidence rates of keratoconus have been estimated to be between 0.2 and 4,790 per 100,000 persons and 1.5 and 25 cases per 100,000 persons/year, respectively, with highest rates typically occurring in 20- to 30-year-olds and Middle Eastern and Asian ethnicities. Progressive stromal thinning, rupture of the anterior limiting membrane, and subsequent ectasia of the central/paracentral cornea are the most commonly observed histopathological findings. A family history of keratoconus, eye rubbing, eczema, asthma, and allergy are risk factors for developing keratoconus. Detecting keratoconus in its earliest stages remains a challenge. Corneal topography is the primary diagnostic tool for keratoconus detection. In incipient cases, however, the use of a single parameter to diagnose keratoconus is insufficient, and in addition to corneal topography, corneal pachymetry and higher order aberration data are now commonly used. Keratoconus severity and progression may be classified based on morphological features and disease evolution, ocular signs, and index-based systems. Keratoconus treatment varies depending on disease severity and progression. Mild cases are typically treated with spectacles, moderate cases with contact lenses, while severe cases that cannot be managed with scleral contact lenses may require corneal surgery. Mild to moderate cases of progressive keratoconus may also be treated surgically, most commonly with corneal cross-linking. This article provides an updated review on the definition, epidemiology, histopathology, aetiology and pathogenesis, clinical features, detection, classification, and management and treatment strategies for keratoconus.
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Affiliation(s)
| | - Gonzalo Carracedo
- Department of Optometry and Vision, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Asaki Suzaki
- Clinical Research and Development Center, Menicon Co., Ltd., Nagoya, Japan
| | - Cesar Villa-Collar
- Department of Pharmacy, Biotechnology, Nutrition, Optics and Optometry, Faculty of Biomedical and Health Sciences, Universidad Europea de Madrid, Madrid, Spain
| | - Stephen J Vincent
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Centre for Vision and Eye Research, Queensland University of Technology, Brisbane, Australia
| | - James S Wolffsohn
- School of optometry, Health and Life Sciences, Aston University, Birmingham B4 7ET, United Kingdom
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23
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Abdolalizadeh P, Ghiasian L, Hadavandkhani A, Eshaghi A, Hadi Y, Nadjafi-Semnani F. Comparing pentacam HR screening indices in different normal corneal thicknesses among refractive surgery candidates. J Curr Ophthalmol 2022; 34:200-207. [PMID: 36147272 PMCID: PMC9487003 DOI: 10.4103/joco.joco_249_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/30/2021] [Accepted: 10/31/2021] [Indexed: 11/10/2022] Open
Abstract
Purpose: To compare Pentacam indices in normal eyes with different corneal thicknesses. Methods: It is a retrospective observational study. Ninety-six normal eyes of 96 patients who were referred for refractive surgery in a tertiary university-based hospital from October 2015 to April 2019 were recruited consecutively. Corneal keratometry as well as Pentacam's software Belin-Ambrósio Enhanced Ectasia Display (BAD) parameters including pachymetry progression indices (PPIs), maximum Ambrosio's relational thickness (ART-max), corneal elevations, normalized deviations, BAD total deviation value (BAD-D), and anterior surface indices were measured by Pentacam HR (Type 70900). The included were classified as thin (26 eyes), average (45 eyes), and thick (25 eyes) corneas with the thinnest point thickness of ≤496 μm, 497–595 μm, and ≥596 μm, respectively. The specificities of all parameters were calculated based on routine cut-off values. Results: The refraction, keratometry, and elevations were not different (P > 0.05). All PPIs (minimum, average, and maximum) of thick corneas were significantly lower than average and thin corneas (P < 0.001). ART-max increased by thickening of the cornea (P < 0.001). BAD-D score and normalized indices of pachymetric parameters decreased with the increase of thickness (P < 0.001), while specificities of all indices increased with corneal thickening. More than 96% of thick corneas were classified as normal PPI-max (24/25), ART-max (25/25), and BAD-D (25/25), while nearly <54% of thin corneas (14/26 for PPI-max, 9/26 for ART-max, and 12/26 for BAD-D) were normal. Conclusions: The pachymetry-related indices and BAD-D were different among normal corneas with various thicknesses. The specificities of PPIs, ART-max, and BAD-D of thin corneas were lower than in thick corneas.
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24
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Vandevenne MMS, Favuzza E, Veta M, Lucenteforte E, Berendschot T, Mencucci R, Nuijts RMMA, Virgili G, Dickman MM. Artificial intelligence for detecting keratoconus. Hippokratia 2021. [DOI: 10.1002/14651858.cd014911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Magali MS Vandevenne
- University Eye Clinic Maastricht; Maastricht University Medical Center (MUMC+); Maastricht Netherlands
| | - Eleonora Favuzza
- Department of Neurosciences, Psychology, Pharmacology and Child Health; University of Florence; Florence Italy
| | - Mitko Veta
- Biomedical Engineering; Eindhoven University of Technology; Eindhoven Netherlands
| | - Ersilia Lucenteforte
- Department of Clinical and Experimental Medicine; University of Pisa; Pisa Italy
| | - Tos Berendschot
- University Eye Clinic Maastricht; Maastricht University Medical Center (MUMC+); Maastricht Netherlands
| | - Rita Mencucci
- Department of Neurosciences, Psychology, Pharmacology and Child Health; University of Florence; Florence Italy
| | - Rudy MMA Nuijts
- University Eye Clinic Maastricht; Maastricht University Medical Center (MUMC+); Maastricht Netherlands
| | - Gianni Virgili
- Department of Neurosciences, Psychology, Pharmacology and Child Health; University of Florence; Florence Italy
- Queen's University Belfast; Belfast UK
| | - Mor M Dickman
- University Eye Clinic Maastricht; Maastricht University Medical Center (MUMC+); Maastricht Netherlands
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25
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Karamichos D, Escandon P, Vasini B, Nicholas SE, Van L, Dang DH, Cunningham RL, Riaz KM. Anterior pituitary, sex hormones, and keratoconus: Beyond traditional targets. Prog Retin Eye Res 2021; 88:101016. [PMID: 34740824 PMCID: PMC9058044 DOI: 10.1016/j.preteyeres.2021.101016] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 12/13/2022]
Abstract
"The Diseases of the Horny-coat of The Eye", known today as keratoconus, is a progressive, multifactorial, non-inflammatory ectatic corneal disorder that is characterized by steepening (bulging) and thinning of the cornea, irregular astigmatism, myopia, and scarring that can cause devastating vision loss. The significant socioeconomic impact of the disease is immeasurable, as patients with keratoconus can have difficulties securing certain jobs or even joining the military. Despite the introduction of corneal crosslinking and improvements in scleral contact lens designs, corneal transplants remain the main surgical intervention for treating keratoconus refractory to medical therapy and visual rehabilitation. To-date, the etiology and pathogenesis of keratoconus remains unclear. Research studies have increased exponentially over the years, highlighting the clinical significance and international interest in this disease. Hormonal imbalances have been linked to keratoconus, both clinically and experimentally, with both sexes affected. However, it is unclear how (molecular/cellular signaling) or when (age/disease stage(s)) those hormones affect the keratoconic cornea. Previous studies have categorized the human cornea as an extragonadal tissue, showing modulation of the gonadotropins, specifically luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Studies herein provide new data (both in vitro and in vivo) to further delineate the role of hormones/gonadotropins in the keratoconus pathobiology, and propose the existence of a new axis named the Hypothalamic-Pituitary-Adrenal-Corneal (HPAC) axis.
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Affiliation(s)
- Dimitrios Karamichos
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA.
| | - Paulina Escandon
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Brenda Vasini
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Sarah E Nicholas
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Lyly Van
- University of Oklahoma Health Sciences Center, 940 Stanton L Young, Oklahoma City, OK, USA; Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Deanna H Dang
- College of Medicine, University of Oklahoma Health Sciences Center, 940 Stanton L Young, Oklahoma City, OK, USA
| | - Rebecca L Cunningham
- Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Kamran M Riaz
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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26
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Fernández J, Peris-Martínez C, Pérez-Rueda A, Hamida Abdelkader SM, Roig-Revert MJ, Piñero DP. Evaluation of a new nomogram for Ferrara ring segment implantation in keratoconus. Int J Ophthalmol 2021; 14:1371-1383. [PMID: 34540613 DOI: 10.18240/ijo.2021.09.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 02/25/2021] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the short-term clinical outcomes of Ferrara rings in keratoconus using an optimized nomogram developed after several years of research and retrospective analysis of clinical data. METHODS This prospective longitudinal non-comparative clinical trial evaluated 88 eyes of 88 patients (age 18-62y) with keratoconus diagnosis from two Spanish centers. Ferrara ring segment (AJL Ophthalmic) implantation was performed in all cases, using the mechanical procedure in 25 eyes (28.4%) and a femtosecond laser-assisted procedure in 63 eyes (71.6%). The ring segments implanted in each case were selected using a new optimized nomogram that considered variables such as anterior corneal asphericity and astigmatism or the discrepancy among astigmatism and coma orientations. Visual, refractive, corneal topographic, aberrometric, and pachymetric changes after surgery were evaluated during a 3-month follow-up. RESULTS The implants induced a significant refractive change as well as an improvement in uncorrected (UDVA) and corrected distance visual acuity (CDVA; P<0.001). Postoperative CDVA of 0.10 logMAR or better was achieved in 28.4% and 46.5% of eyes, respectively. Two eyes (2.3%) lost two or more lines of CDVA whereas a total of 53.5% of eyes gained lines of CDVA. A significant central anterior and posterior corneal flattening was induced (P≤0.003), with a significant reduction of anterior (P<0.001) and posterior corneal astigmatisms (P=0.048), and a change in anterior asphericity (P<0.001). Total primary coma (6 mm pupil) change was also statistically significant (preoperative 3.66±3.04 µm vs postoperative 2.33±2.26 µm, P<0.001). No significant differences were found in the effect of ring segments between cases implanted using the mechanical and femtosecond techniques (P≥0.101). CONCLUSION The implantation of Ferrara rings based on the nomogram evaluated is safe and effective for promoting a visual rehabilitation in keratoconus, with a relevant control of primary coma aberration.
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Affiliation(s)
- Joaquín Fernández
- Department of Ophthalmology (Qvision), Vithas Virgen del Mar Hospital, Almería 04120, Spain.,Department of Ophthalmology, Torrecárdenas Hospital Complex, Almería 04009, Spain
| | - Cristina Peris-Martínez
- Cornea and External Diseases Unit, FISABIO-Oftalmología Médica (FOM), Valencia 46015, Spain.,Aviño Peris Eye Clinic, Valencia 46001, Spain.,Department of Surgery, Ophthalmology, University of Valencia, Valencia 46010, Spain
| | - Antonio Pérez-Rueda
- Department of Ophthalmology, Torrecárdenas Hospital Complex, Almería 04009, Spain
| | | | - María José Roig-Revert
- Cornea and External Diseases Unit, FISABIO-Oftalmología Médica (FOM), Valencia 46015, Spain.,Department of Surgery, Ophthalmology, University of Valencia, Valencia 46010, Spain
| | - David P Piñero
- Department of Optics, Pharmacology, and Anatomy, University of Alicante, Alicante 03690, Spain
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Case Series: Application of Topography-guided Contoura Refractive Surgery in Highly Irregular Cornea. Optom Vis Sci 2021; 98:557-562. [PMID: 34091500 DOI: 10.1097/opx.0000000000001703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE Highly irregular cornea leads to poor vision, glare, and starbursts. Although treatment is still at the exploration stage, topography-guided Contoura surgery has excellent potential for the treatment of highly irregular corneas. PURPOSE This case series reviews three patients (one with abnormal back elevation, one with corneal scar after fungal keratitis, and one with post-laser-assisted in situ keratomileusis central islands) treated with topography-guided Contoura surgery. CASE REPORTS In case 1, a 19-year-old man underwent topography-guided Contoura refractive surgery in the left eye and wavefront-optimized ablation in the right eye. Post-operative topography of the right eye showed marked inferior steepening and central irregular astigmatism compared with the contralateral eye. In case 2, a 53-year-old man presented with corneal scarring on the right eye after recovering from fungal keratitis. The patient first underwent phototherapeutic keratectomy and photorefractive keratectomy to remove the scarring primarily. He then underwent Contoura to correct hyperopia, which flattened the cornea and improved his vision significantly. In case 3, a 25-year-old man presented with central steepening on topography maps after undergoing laser-assisted in situ keratomileusis. He underwent topography-guided ablation, which improved his visual acuity and normalized the cornea. CONCLUSIONS Therapy for highly irregular corneas includes wavefront-guided surgery, conservative treatment, corneal transplantation, rigid gas-permeable lenses, and so on. In this case series, topography-guided Contoura refractive surgery provided an excellent option for reducing topographic abnormalities and improving vision.
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28
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Donoso R, Rodríguez Á, Esteffan K, Lagos C, Aránguiz D, Hernández N. Analysis of OPD-Scan and Pentacam Parameters for Early Keratoconus Detection. Am J Ophthalmol 2021; 226:235-242. [PMID: 33529586 DOI: 10.1016/j.ajo.2021.01.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 11/15/2020] [Accepted: 01/20/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND PURPOSE: To evaluate Pentacam and OPD-Scan parameters in the early detection of keratoconus. DESIGN Retrospective case-control study. METHODS Case group included 50 clinically unaffected fellow eyes diagnosed with asymmetric keratoconus showing subtle qualitative changes at the 0.5-D sensitivity OPD-Scan scale, as well as normal anterior and back elevation difference map at Belin/Ambrósio enhanced ectasia display (BAD) at the Pentacam. Control group included 172 normal eyes that underwent Lasik surgery and presented no complications throughout the 2-year follow-up period. OPD-Scan and Pentacam parameters were compared, calculating sensitivity, specificity, and area under the receiver operating characteristic curve (AUC). A multivariate analysis was performed using Pentacam or OPD-Scan variables, and a model using variables of both devices. RESULTS Pentacam variables with AUC ≥0.8 were keratoconus index (0.85), index of height decentration (0.81), and overall deviation at BAD (0.8). OPD-Scan variables with AUC ≥0.8 were keratoconus prediction index (0.83), surface asymmetry index (0.83), and total of higher-order trefoil aberration (0.8). In the multivariate analysis, the AUC was 0.85 in the case of OPD-Scan whereas it was 0.89 in the case of Pentacam. When combining all variables from the 2 devices, the AUC was 0.93, with a sensitivity of 82% and a specificity of 94%. CONCLUSIONS Several parameters of OPD-Scan and Pentacam can be useful to differentiate cases from normal control eyes, demonstrating even better results when combining parameters of both devices. Anterior corneal indexes were the most important parameters to discriminate both groups.
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Affiliation(s)
- Rodrigo Donoso
- From the Department of Ophthalmology, Faculty of Medicine, Universidad de Chile (R.D., A.R., K.E.), Clínica Oftalmológica Pasteur (R.D., A.R., K.E., D.A., N.H.), and Department of Radiology, Pontificia Universidad Católica de Chile (C.L.), Santiago, Chile.
| | - Álvaro Rodríguez
- From the Department of Ophthalmology, Faculty of Medicine, Universidad de Chile (R.D., A.R., K.E.), Clínica Oftalmológica Pasteur (R.D., A.R., K.E., D.A., N.H.), and Department of Radiology, Pontificia Universidad Católica de Chile (C.L.), Santiago, Chile
| | - Karim Esteffan
- From the Department of Ophthalmology, Faculty of Medicine, Universidad de Chile (R.D., A.R., K.E.), Clínica Oftalmológica Pasteur (R.D., A.R., K.E., D.A., N.H.), and Department of Radiology, Pontificia Universidad Católica de Chile (C.L.), Santiago, Chile
| | - Claudio Lagos
- From the Department of Ophthalmology, Faculty of Medicine, Universidad de Chile (R.D., A.R., K.E.), Clínica Oftalmológica Pasteur (R.D., A.R., K.E., D.A., N.H.), and Department of Radiology, Pontificia Universidad Católica de Chile (C.L.), Santiago, Chile
| | - Diego Aránguiz
- From the Department of Ophthalmology, Faculty of Medicine, Universidad de Chile (R.D., A.R., K.E.), Clínica Oftalmológica Pasteur (R.D., A.R., K.E., D.A., N.H.), and Department of Radiology, Pontificia Universidad Católica de Chile (C.L.), Santiago, Chile
| | - Nicolás Hernández
- From the Department of Ophthalmology, Faculty of Medicine, Universidad de Chile (R.D., A.R., K.E.), Clínica Oftalmológica Pasteur (R.D., A.R., K.E., D.A., N.H.), and Department of Radiology, Pontificia Universidad Católica de Chile (C.L.), Santiago, Chile
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Molina‐martín A, Piñero DP, Caballero MT, Fez D, Camps VJ. Comparative analysis of anterior corneal curvature and astigmatism measurements obtained with three different devices. Clin Exp Optom 2021; 103:618-624. [DOI: 10.1111/cxo.13002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 09/04/2019] [Accepted: 10/09/2019] [Indexed: 11/28/2022] Open
Affiliation(s)
- Ainhoa Molina‐martín
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
| | - David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
- Department of Ophthalmology, Vithas Medimar International Hospital, Alicante, Spain,
| | - María T Caballero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
| | - Dolores Fez
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
| | - Vicent J Camps
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
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Wallerstein A, Gauvin M, Mimouni M, Racine L, Salimi A, Cohen M. Keratoconus Features on Corneal Higher-Order Aberration Ablation Maps: Proof-of-Concept of a New Diagnostic Modality. Clin Ophthalmol 2021; 15:623-633. [PMID: 33623363 PMCID: PMC7896763 DOI: 10.2147/opth.s296724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 01/18/2021] [Indexed: 11/27/2022] Open
Abstract
PURPOSE To assess the potential application of corneal higher-order aberration (HOA) excimer ablation map imaging in identifying reproducible keratoconus (KC) features and to explore if newly derived map metrics correlate to Pentacam KC indices. METHODS Case series of 12 eyes with KC ≥ grade 2. Topolyzer Vario corneal imaging with its resultant HOA ablation map islands were analyzed for their centroid, distance from center, angular position, orientation, sphericity, diameter, area, and maximal ablation depth. Correlations to Pentacam indices were studied. RESULTS All eyes showed recurrent features with an arrangement of two elliptical paracentral ablation islands, one deep inferotemporal and one shallow superonasal, in direct mirror-like opposition to each other. These were always accompanied by superior peripheral ablation crescents. The two paracentral islands had highly reproducible distance from center (1.2 ± 0.1 mm and 1.3 ± 0. 2 mm) and angular positions (246.8 ± 15.9° and 76.7 ± 7.7°), with greater variation in ablation depth (68.3 ± 33.2 µm and 17.6 ± 12.1 µm). Distance from center of the peripheral superior crescents was highly reproducible (3.3 ± 0.1 mm), with a larger range of depth (74.5 ± 37.2 µm). The deep paracentral inferotemporal island "hot spot" was coincident with the topographical apical cone. Strong correlations were found between the depth of the inferotemporal island and Pentacam indices of posterior radius curvature (PRC: R = -0.74) and Belin/Ambrosio enhanced ectasia total deviation (BAD-D: R = 0.71). CONCLUSION The corneal HOA ablation map revealed a recurring, distinct, easily recognizable pattern in KC eyes. There was a strong correlation between the depth of novel HOA ablation map metrics and validated Pentacam KC indices. Novel information can be extracted from the corneal HOA ablation map giving it the potential to be a new modality to diagnose and grade KC.
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Affiliation(s)
- Avi Wallerstein
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, QC, Canada
- LASIK MD, Montreal, QC, Canada
| | - Mathieu Gauvin
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, QC, Canada
- LASIK MD, Montreal, QC, Canada
| | - Michael Mimouni
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
| | - Louis Racine
- Department of Ophthalmology, University of Montreal, Montreal, QC, Canada
| | - Ali Salimi
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, QC, Canada
- LASIK MD, Montreal, QC, Canada
| | - Mark Cohen
- LASIK MD, Montreal, QC, Canada
- Department of Surgery, University of Sherbrooke, Sherbrooke, QC, Canada
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Henriquez MA, Hadid M, Izquierdo L. A Systematic Review of Subclinical Keratoconus and Forme Fruste Keratoconus. J Refract Surg 2021; 36:270-279. [PMID: 32267959 DOI: 10.3928/1081597x-20200212-03] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 02/10/2020] [Indexed: 02/07/2023]
Abstract
PURPOSE To identify the definitions used for the terms sub-clinical keratoconus and forme fruste keratoconus in published articles. METHODS This was a prospective, systematic literature review of the electronic database in PubMed, the Cochrane Library, and LILACS Database of all studies using the keywords "subclinical keratoconus" and/or "forme fruste keratoconus" until August 18, 2017. Two independent reviewers analyzed the data. The inclusion criteria for articles were having analyzed subclinical keratoconus or forme fruste keratoconus eyes with a sample size greater than 10 eyes; containing the definition of subclinical keratoconus or forme fruste keratoconus; and the quality of published reports was assessed using standards quality index methods. The following aspects of the selected articles were then analyzed: inclusion criteria for definition and technology used. RESULTS A total of 198 and 95 studies, respectively, including the definition of subclinical keratoconus and forme fruste keratoconus were collected in an initial search, of which 165 and 73 studies, respectively, were excluded. Definitions for subclinical keratoconus and forme fruste keratoconus included the criteria of having keratoconus in the fellow eye in 72.72% (24 of 33) and 77.27% (17 of 22) of the articles, respectively. A total of 96.97% (32 of 33) and 90.90% (20 of 22) of the studies used more than one parameter to define subclinical keratoconus and forme fruste keratoconus, respectively. The most common extra parameters included normal slit-lamp examination and cornea on slit-lamp biomicroscopy and inferior-superior asymmetry and/or bowtie pattern with skewed radial axes. CONCLUSIONS This review demonstrates the lack of unified criteria to define subclinical keratoconus and forme fruste keratoconus. According to the literature review, the most common subclinical keratoconus definition used refers to an eye with topographic signs of keratoconus and/or suspicious topographic findings under normal slit-lamp examination and keratoconus in the fellow eye and the most common forme fruste keratoconus definition refers to an eye with normal topography, normal slit-lamp examination, and keratoconus in the fellow eye. [J Refract Surg. 2020;36(4):270-279.].
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Jiménez-García M, Ní Dhubhghaill S, Koppen C, Varssano D, Rozema JJ. Baseline Findings in the Retrospective Digital Computer Analysis of Keratoconus Evolution (REDCAKE) Project. Cornea 2021; 40:156-167. [PMID: 32541189 DOI: 10.1097/ico.0000000000002389] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 03/31/2020] [Indexed: 02/07/2023]
Abstract
PURPOSE To present the baseline data for a large cohort of patients with keratoconus enrolled in the Retrospective Digital Computer Analysis of Keratoconus Evolution (REDCAKE) study. METHODS Eight centers contributed the Scheimpflug tomographical data for 906 patients with keratoconus, 743 measured with a Pentacam and 163 with a Galilei. The stage of keratoconus at baseline, the location of the reference points, minimum pachymetry (Pmin), and maximum keratometry (Kmax) were analyzed. The intereye asymmetry was evaluated for Kmax (anterior and posterior), Pmin, and keratoconus stage. Average maps and elevation profiles were calculated for each degree of keratoconus. RESULTS Keratoconus was more frequently diagnosed in men (73%) than in women (27%). At baseline, 500/1155 eyes (43%) presented with moderate to severe changes in the posterior surface, whereas moderate/severe changes were only found in 252 and 63 eyes when evaluating anterior surface and pachymetry, respectively. The location of Pmin was usually inferotemporal (94% OD and 94% OS), while the location of Kmax showed more variability and significantly higher distance from apex (P < 0.05). The keratoconus presentation was chiefly asymmetric for all the parameters studied. Clear differences between stages could be identified in the maps and elevation profiles. CONCLUSIONS The staging map set presented can be used as a graphical guidance to classify keratoconus stage. Keratoconus presented asymmetrically, and generally the posterior surface was more affected than the anterior surface or the thickness. Asymmetry is playing a role in KC detection. Although Pmin was almost invariably located inferotemporally, Kmax location showed higher variability and distance from the apex.
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Affiliation(s)
- Marta Jiménez-García
- Department of Ophthalmology, Antwerp University Hospital (UZA), Edegem, Belgium
- Department of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium ; and
| | - Sorcha Ní Dhubhghaill
- Department of Ophthalmology, Antwerp University Hospital (UZA), Edegem, Belgium
- Department of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium ; and
| | - Carina Koppen
- Department of Ophthalmology, Antwerp University Hospital (UZA), Edegem, Belgium
- Department of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium ; and
| | - David Varssano
- Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jos J Rozema
- Department of Ophthalmology, Antwerp University Hospital (UZA), Edegem, Belgium
- Department of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium ; and
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Shi C, Wang M, Zhu T, Zhang Y, Ye Y, Jiang J, Chen S, Lu F, Shen M. Machine learning helps improve diagnostic ability of subclinical keratoconus using Scheimpflug and OCT imaging modalities. EYE AND VISION 2020; 7:48. [PMID: 32974414 PMCID: PMC7507244 DOI: 10.1186/s40662-020-00213-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 08/19/2020] [Indexed: 12/26/2022]
Abstract
Purpose To develop an automated classification system using a machine learning classifier to distinguish clinically unaffected eyes in patients with keratoconus from a normal control population based on a combination of Scheimpflug camera images and ultra-high-resolution optical coherence tomography (UHR-OCT) imaging data. Methods A total of 121 eyes from 121 participants were classified by 2 cornea experts into 3 groups: normal (50 eyes), with keratoconus (38 eyes) or with subclinical keratoconus (33 eyes). All eyes were imaged with a Scheimpflug camera and UHR-OCT. Corneal morphological features were extracted from the imaging data. A neural network was used to train a model based on these features to distinguish the eyes with subclinical keratoconus from normal eyes. Fisher’s score was used to rank the differentiable power of each feature. The receiver operating characteristic (ROC) curves were calculated to obtain the area under the ROC curves (AUCs). Results The developed classification model used to combine all features from the Scheimpflug camera and UHR-OCT dramatically improved the differentiable power to discriminate between normal eyes and eyes with subclinical keratoconus (AUC = 0.93). The variation in the thickness profile within each individual in the corneal epithelium extracted from UHR-OCT imaging ranked the highest in differentiating eyes with subclinical keratoconus from normal eyes. Conclusion The automated classification system using machine learning based on the combination of Scheimpflug camera data and UHR-OCT imaging data showed excellent performance in discriminating eyes with subclinical keratoconus from normal eyes. The epithelial features extracted from the OCT images were the most valuable in the discrimination process. This classification system has the potential to improve the differentiable power of subclinical keratoconus and the efficiency of keratoconus screening.
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Affiliation(s)
- Ce Shi
- School of Ophthalmology and Optometry, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang, 325027 China
| | - Mengyi Wang
- School of Ophthalmology and Optometry, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang, 325027 China
| | - Tiantian Zhu
- College of Computer Science and Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 12624 China
| | - Ying Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang, 325027 China
| | - Yufeng Ye
- School of Ophthalmology and Optometry, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang, 325027 China
| | - Jun Jiang
- School of Ophthalmology and Optometry, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang, 325027 China
| | - Sisi Chen
- School of Ophthalmology and Optometry, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang, 325027 China
| | - Fan Lu
- School of Ophthalmology and Optometry, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang, 325027 China
| | - Meixiao Shen
- School of Ophthalmology and Optometry, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang, 325027 China
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Dimacali V, Balidis M, Adamopoulou A, Kozei A, Kozeis N. A Case of Early Keratoconus Associated with Eye Rubbing in a Young Child. Ophthalmol Ther 2020; 9:667-676. [PMID: 32542504 PMCID: PMC7406581 DOI: 10.1007/s40123-020-00264-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Indexed: 02/07/2023] Open
Abstract
INTRODUCTION Keratoconus usually presents during puberty and is considered rare in young children. METHODS Case report with clinical findings and computerized corneal tomography. RESULTS We report the case of an 8-year-old girl with early bilateral keratoconus who presented with allergic conjunctivitis and persistent eye rubbing. Although our patient did not exhibit steep keratometry, early cones and inferotemporal thinnest corneal thicknesses were detected in both eyes using Scheimpflug imaging (Oculus GmbH Pentacam, Wetzlar, Germany). Belin/Ambrósio total D values were 1.85 on the right and 2.11 on the left. Improvement in best-corrected visual acuity was noted after treatment of allergic eye disease, and corneal tomographic findings remained stable 4 months after initial consult. CONCLUSION This is a case of early diagnosed keratoconus in a young patient. Diagnosis of this condition in young children is challenging, as these patients are less likely to report visual complaints, and clinical examination is usually unremarkable. Keratoconus screening should be considered in children with atopy and eye rubbing behavior regardless of age, even in those with no other associated pathology and with negative family history.
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Affiliation(s)
- Victoria Dimacali
- Ophthalmica Institute of Ophthalmology and Microsurgery, Thessaloniki, Greece
- Makati Medical Center, Metro Manila, Philippines
| | - Miltos Balidis
- Ophthalmica Institute of Ophthalmology and Microsurgery, Thessaloniki, Greece
| | - Aspasia Adamopoulou
- Ophthalmica Institute of Ophthalmology and Microsurgery, Thessaloniki, Greece
| | - Athina Kozei
- Ophthalmica Institute of Ophthalmology and Microsurgery, Thessaloniki, Greece
- Pediatric Eye Center of Greece, Thessaloniki, Greece
- School of Pharmacology, University of Nicosia, Nicosia, Cyprus
| | - Nikolaos Kozeis
- Ophthalmica Institute of Ophthalmology and Microsurgery, Thessaloniki, Greece.
- Pediatric Eye Center of Greece, Thessaloniki, Greece.
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Relationship between Corneal Morphogeometrical Properties and Biomechanical Parameters Derived from Dynamic Bidirectional Air Applanation Measurement Procedure in Keratoconus. Diagnostics (Basel) 2020; 10:diagnostics10090640. [PMID: 32867063 PMCID: PMC7555946 DOI: 10.3390/diagnostics10090640] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/25/2020] [Accepted: 08/25/2020] [Indexed: 02/07/2023] Open
Abstract
The morphogeometric analysis of the corneal structure has become a clinically relevant diagnostic procedure in keratoconus (KC) as well as the in vivo evaluation of the corneal biomechanical properties. However, the relationship between these two types of metrics is still not well understood. The current study investigated the relationship of corneal morphogeometry and volume with two biomechanical parameters: corneal hysteresis (CH) and corneal resistance factor (CRF), both provided by an Ocular Response Analyzer (Reichert). It included 109 eyes from 109 patients (aged between 18 and 69 years) with a diagnosis of keratoconus (KC) who underwent a complete eye examination including a comprehensive corneal topographic analysis with the Sirius system (CSO). With the topographic information obtained, a morphogeometric and volumetric analysis was performed, defining different variables of clinical use. CH and CRF were found to be correlated with these variables, but this correlation was highly influenced by corneal thickness. This suggests that the mechanical properties of KC cornea contribute only in a partial and limited manner to these biomechanical parameters, being mostly influenced by morphogeometry under normal intraocular pressure levels. This would explain the limitation of CH and CRF as diagnostic tools for the detection of incipient cases of KC.
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Mohammadpour M, Farhadi B, Mirshahi R, Masoumi A, Mirghorbani M. Simultaneous photorefractive keratectomy and accelerated collagen cross-linking in high-risk refractive surgery (Tehran protocol): 3-year outcomes. Int Ophthalmol 2020; 40:2659-2666. [PMID: 32607947 DOI: 10.1007/s10792-020-01447-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 05/23/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE To evaluate safety and efficacy of performing simultaneous photorefractive keratectomy (PRK) and collagen cross-linking (CXL) in myopic patients with preoperative risk factors for developing keratectasia. METHODS Seventeen eyes of 15 patients with at least one of the following risk factors were recruited: central keratometry (Kmax) between 48 and 50, difference between inferior, superior corneal power (I-S value) between 1.4 and 1.9 and corneal thickness between 450 and 480 µm. Upon final stage of standard PRK, 0.02% mitomycin was applied for 30-50 s, and then, accelerated CXL was performed for 5 min. Pre- and postoperative Oculus Pentacam® imaging for keratometry values, measurement of uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were done for all patients. RESULTS Mean follow-up time was 32.08 ± 7.79 months (range 25-49 months). Mean age of patients was 28.78 ± 3.80 years. Mean postoperative spherical equivalent was + 0.19 ± 0.42 (- 0.5 to + 1.0 [D]). Mean UDVA and CDVA improved from 0.9062 ± 0.485 log MAR and 0.0148 ± 0.043 log MAR to 0.0173 ± 0.040 log MAR and 0.0057 ± 0.023 log MAR, respectively (P = 0.011, P = 0.735). Mild degree of early postoperative stromal haze was seen which did not persist more than 6 months. There was no late stromal haze, corneal ectasia or other major postoperative complication in the follow-up period. CONCLUSION Combined PRK and accelerated CXL is an efficient and safe procedure for high-risk refractive surgery candidates, with no increased risk of persistent corneal haze.
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Affiliation(s)
- Mehrdad Mohammadpour
- Ophthalmology Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, 1336616351, Iran
| | - Behnaz Farhadi
- Ophthalmology Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, 1336616351, Iran
| | - Reza Mirshahi
- Ophthalmology Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, 1336616351, Iran.,Eye Research Center, Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Ahmad Masoumi
- Ophthalmology Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, 1336616351, Iran.
| | - Masoud Mirghorbani
- Ophthalmology Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, 1336616351, Iran
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Shneor E, Frucht‐Pery J, Granit E, Gordon‐Shaag A. The prevalence of corneal abnormalities in first-degree relatives of patients with keratoconus: a prospective case-control study. Ophthalmic Physiol Opt 2020; 40:442-451. [PMID: 32706487 PMCID: PMC7496242 DOI: 10.1111/opo.12706] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 05/20/2020] [Indexed: 12/29/2022]
Abstract
PURPOSE Although there is a high prevalence of keratoconus in the Middle East including Israel, limited data is available describing first-degree relatives of patients with sporadic keratoconus (KC) using Scheimpflug imaging. The purpose of this study is to accurately phenotype first-degree relatives of patients with sporadic KC in Israel using corneal tomography, which may help determine the genetic aetiology of KC. METHODS First-degree relatives (N = 56) of 16 KC probands participated in this prospective case-control study. Healthy controls (N = 96) were from a previous study. Autorefraction, visual acuity, slit lamp biomicroscopy, retinoscopy, subjective refraction and Scheimpflug imaging (CSO Sirius Topographer) of keratoconus patients and their first-degree relatives were evaluated. The worse eye was used for KC and KC suspects. The main outcome measure was prevalence of abnormal corneal topography and tomography parameters, which was compared between first-degree relatives vs controls. p values < 0.05 were considered significant. RESULTS KC (N = 2) or KC suspect (N = 8) was diagnosed in 18% (95% CI 8-28%) of the first-degree relatives. At least one abnormal corneal parameter was evident in 34% of first-degree relatives, while this was significantly lower for controls (14%, χ2(1,N = 152) = 8.8, p = 0.01). Qualitative analysis showed KC first-degree relatives had significantly more abnormal anterior corneal topography patterns than controls (34% vs 17%, χ2(1,N = 152) = 5.9, p = 0.02). For first-degree relatives, sex was not a factor influencing prevalence of corneal abnormalities (18% for both men and women, χ2(1,N = 56) = 0.0, p = 1.0). A significant correlation was found for first-degree relatives between age and most corneal parameters, while this was not evident for the control group. CONCLUSIONS AND RELEVANCE Eye care practitioners should consider first-degree relatives of patients with KC at moderate risk for the disease and/or corneal abnormalities.
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Affiliation(s)
- Einat Shneor
- Department of Optometry and Vision ScienceHadassah Academic CollegeJerusalemIsrael
| | - Joseph Frucht‐Pery
- Department of Optometry and Vision ScienceHadassah Academic CollegeJerusalemIsrael
| | - Edna Granit
- Department of Optometry and Vision ScienceHadassah Academic CollegeJerusalemIsrael
| | - Ariela Gordon‐Shaag
- Department of Optometry and Vision ScienceHadassah Academic CollegeJerusalemIsrael
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Velázquez JS, Cavas F, Piñero DP, Cañavate FJ, Alio del Barrio J, Alio JL. Morphogeometric analysis for characterization of keratoconus considering the spatial localization and projection of apex and minimum corneal thickness point. J Adv Res 2020; 24:261-271. [PMID: 32382446 PMCID: PMC7200195 DOI: 10.1016/j.jare.2020.03.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 03/26/2020] [Accepted: 03/26/2020] [Indexed: 02/07/2023] Open
Abstract
This work evaluates changes in new morphogeometric indices developed considering the position of anterior and posterior corneal apex and minimum corneal thickness (MCT) point in keratoconus. This prospective comparative study included 440 eyes of 440 patients (age, 7-99 years): control (124 eyes) and keratoconus (KC) groups (316 eyes). Tomographic information (Sirius®, Costruzione Strumenti Oftalmici, Italy) was treated with SolidWorks v2013, creating the following morphogeometric parameters: geometric axis-apex line angle (GA-AP), geometric axis-MCT line angle (GA-MCT, apex line-MCT line angle (AP-MCT), and distances between apex and MCT points on the anterior (anterior AP-MCTd) and posterior corneal surface (posterior AP-MCTd). Statistically significant higher values of GA-AP, GA-MCT, AP-MCT and anterior AP-MCTd were found in the keratoconus group (p ≤ 0.001). Moderate significant correlations of corneal aberrations (r ≥ 0.587, p < 0.001) and corneal thickness parameters (r ≤ -0.414, p < 0.001) with GA-AP and AP-MCT were found. Anterior asphericity was found to be significantly correlated with anterior and posterior AP-MCTd (r ≥ 0.430, p < 0.001). Likewise, GA-AP and AP-MCT showed a good diagnostic ability for the detection of keratoconus, with optimal cutoff values of 9.61° (sensitivity 85.5%, specificity 80.3%) and 18.08° (sensitivity 80.5%, specificity 78.7%), respectively. These new morphogeometric indices allow a clinical characterization of the 3-D structural alteration occurring in keratoconus, with less coincidence in the spatial projection of the apex and MCT points of both corneal surfaces. Future studies should confirm the potential impact on the precision of these indices of the variability of posterior corneal surface measurements obtained with Scheimpflug imaging technology.
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Affiliation(s)
- Jose S. Velázquez
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, 30202 Cartagena, Spain
| | - Francisco Cavas
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, 30202 Cartagena, Spain
| | - David P. Piñero
- Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain
| | - Francisco J.F. Cañavate
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, 30202 Cartagena, Spain
| | - Jorge Alio del Barrio
- Division of Ophthalmology, Miguel Hernández University, 03690 Alicante, Spain
- Keratoconus Unit of Vissum Corporation Alicante, 03690 Alicante, Spain
- Department of Refractive Surgery, Vissum Corporation Alicante, 03690 Alicante, Spain
| | - Jorge L. Alio
- Division of Ophthalmology, Miguel Hernández University, 03690 Alicante, Spain
- Keratoconus Unit of Vissum Corporation Alicante, 03690 Alicante, Spain
- Department of Refractive Surgery, Vissum Corporation Alicante, 03690 Alicante, Spain
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Alifa R, Piñero D, Velázquez J, L. Alió del Barrio J, Cavas F, Alió JL. Changes in the 3D Corneal Structure and Morphogeometric Properties in Keratoconus after Corneal Collagen Crosslinking. Diagnostics (Basel) 2020; 10:diagnostics10060397. [PMID: 32545294 PMCID: PMC7345591 DOI: 10.3390/diagnostics10060397] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/08/2020] [Accepted: 06/09/2020] [Indexed: 02/07/2023] Open
Abstract
Keratoconus is an ectatic disorder that is presently considered one of the most prevalent reasons for keratoplasty. Corneal collagen crosslinking (CXL) is the only proven treatment option available that is capable of halting the progression of the disease by stabilizing the cone in 90% of cases, and by also reducing refractive error and maximal keratometry. This study assesses, by means of a 3D morphogeometric analysis procedure developed by our research team, the corneal structure changes that occur immediately after CXL treatment and during a 6 month follow-up period. A total of 19 eyes from 19 patients diagnosed with keratoconus who underwent CXL were included, and several variables derived from the morphogeometric analysis were calculated and evaluated for the pre-operative, 3 month postoperative, and 6 month postoperative states. Significant reductions were detected in central corneal thickness and corneal spherical-like root mean square (RMS) 3 months after surgery, with non-significant regression of the effect afterward. Significant reductions in the total corneal area/volume were found, with some levels of regression after 6 months in certain volumetric parameters. In conclusion, the eyes with higher values for morphogeometric parameters—posterior apex deviation (PAD), anterior minimum thickness point deviation (AMTPD), and posterior minimum thickness point deviation (PMTPD)—seemed more likely to undergo aberrometric improvement as a result of CXL surgery.
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Affiliation(s)
- Ramón Alifa
- Doctorate Program in Industrial Technologies, International School of Doctorate, Technical University of Cartagena, 30202 Cartagena, Spain;
| | - David Piñero
- Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain;
| | - José Velázquez
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, 30202 Cartagena, Spain;
| | - Jorge L. Alió del Barrio
- Department of Research and Development, VISSUM, 03016 Alicante, Spain; (J.L.A.d.B.); (J.L.A.)
- Cornea, Cataract and Refractive Surgery Department, VISSUM, 03016 Alicante, Spain
- Division of Ophthalmology, Department of Pathology and Surgery, Faculty of Medicine, Miguel Hernández University, 03202 Alicante, Spain
| | - Francisco Cavas
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, 30202 Cartagena, Spain;
- Correspondence: ; Tel.: +34-968-328856
| | - Jorge L. Alió
- Department of Research and Development, VISSUM, 03016 Alicante, Spain; (J.L.A.d.B.); (J.L.A.)
- Cornea, Cataract and Refractive Surgery Department, VISSUM, 03016 Alicante, Spain
- Division of Ophthalmology, Department of Pathology and Surgery, Faculty of Medicine, Miguel Hernández University, 03202 Alicante, Spain
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Velázquez-Blázquez JS, Bolarín JM, Cavas-Martínez F, Alió JL. EMKLAS: A New Automatic Scoring System for Early and Mild Keratoconus Detection. Transl Vis Sci Technol 2020; 9:30. [PMID: 32832203 PMCID: PMC7410118 DOI: 10.1167/tvst.9.2.30] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 04/01/2020] [Indexed: 01/01/2023] Open
Abstract
Purpose Create a unique predictive model based on a set of demographic, optical, and geometric variables with two objectives: classifying keratoconus (KC) in its first clinical manifestation stages and establishing the probability of having correctly classified each case. Methods We selected 178 eyes of 178 subjects (115 males; 64.6%; 63 females, 35.4%). Of these, 74 were healthy control subjects, and 104 suffered from KC according to the RETICS grading system (61 early KC, 43 mild KC). Only one eye from each patient was selected, and 27 different parameters were studied (demographic, clinical, pachymetric, and geometric). The data obtained were used in an ordinal logistic regression model programmed as a web application capable of using new patient data for real-time predictions. Results EMKLAS, an early and mild KC classifier, showed good training performance figures, with 73% global accuracy and a 95% confidence interval of 65% to 79%. This classifier is particularly accurate when validated by an independent sample for the control (79%) and mild KC (80%) groups. The accuracy of the early KC group was remarkably lower (69%). The variables included in the model were age, gender, corrected distance visual acuity, 8-mm corneal diameter, and posterior minimum thickness point deviation. Conclusions Our web application allows fast, objective, and quantitative assessment of early and mild KC in detection and classification terms and assists ophthalmology professionals in diagnosing this disease. Translational Relevance No single gold standard exists for detecting and classifying preclinical KC, but the use of our web application and EMKLAS score may aid the decision-making process of doctors.
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Affiliation(s)
- Jose S. Velázquez-Blázquez
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, Cartagena, Spain
| | - José M. Bolarín
- Technology Centre for IT and Communications (CENTIC), Scientific Park of Murcia, Murcia, Spain
| | - Francisco Cavas-Martínez
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, Cartagena, Spain
| | - Jorge L. Alió
- Keratoconus Unit, Vissum Corporation Alicante, Alicante, Spain
- Department of Ophthalmology, Miguel Hernández University of Elche, Alicante, Spain
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A Machine-Learning Model Based on Morphogeometric Parameters for RETICS Disease Classification and GUI Development. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10051874] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This work pursues two objectives: defining a new concept of risk probability associated with suffering early-stage keratoconus, classifying disease severity according to the RETICS (Thematic Network for Co-Operative Research in Health) scale. It recruited 169 individuals, 62 healthy and 107 keratoconus diseased, grouped according to the RETICS classification: 44 grade I; 18 grade II; 15 grade III; 15 grade IV; 15 grade V. Different demographic, optical, pachymetric and eometrical parameters were measured. The collected data were used for training two machine-learning models: a multivariate logistic regression model for early keratoconus detection and an ordinal logistic regression model for RETICS grade assessments. The early keratoconus detection model showed very good sensitivity, specificity and area under ROC curve, with around 95% for training and 85% for validation. The variables that made the most significant contributions were gender, coma-like, central thickness, high-order aberrations and temporal thickness. The RETICS grade assessment also showed high-performance figures, albeit lower, with a global accuracy of 0.698 and a 95% confidence interval of 0.623–0.766. The most significant variables were CDVA, central thickness and temporal thickness. The developed web application allows the fast, objective and quantitative assessment of keratoconus in early diagnosis and RETICS grading terms.
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Gustafsson I, Bergström A, Myers AC, Ivarsen A, Hjortdal J. Association between keratoconus disease severity and repeatability in measurements of parameters for the assessment of progressive disease. PLoS One 2020; 15:e0228992. [PMID: 32059036 PMCID: PMC7021304 DOI: 10.1371/journal.pone.0228992] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 01/28/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Progressive keratoconus can lead to severely impaired vision, but there is currently no consensus on the definition of progressive disease. Errors in the measurement of the parameters commonly used to establish progressive disease were evaluated in an attempt to determine the limits at which a true change in the values can be detected. The possible association between measurement error and disease severity was also investigated to evaluate the need for limits based on disease severity. METHODS Sixty-one eyes were studied in 61 patients with keratoconus. Four replicate measurements were made in each patient using a Scheimpflug-based tomographic system (denoted the PC) and an auto-keratometer (denoted the AK). The repeatability coefficient, i.e., the level below which differences between two measurements are found in 95% of paired observations, was calculated. Patients were further divided into three groups based on disease severity (parameter magnitude). RESULTS Increasing magnitude of all the keratometric parameters investigated was significantly associated with increasing measurement errors, and thus worse repeatability. The maximum keratometry value (Kmax) was the least repeatable parameter (1.23 D, 95% CI 1.11-1.35 D) and showed the strongest association between parameter magnitude and measurement error. The repeatability coefficient ranged between 0.32 and 1.62 D, depending on disease severity. The most repeatable parameter was the flattest central keratometry value (K1), measured with the PC (0.51 D, 95% CI 0.46-0.56 D) and the AK (0.54 D, 95% CI 0.48-0.59 D). K1 showed the weakest association between parameter magnitude and measurement error. The repeatability coefficient for K1 ranged between 0.40 and 0.54 D when using the PC, and between 0.34 and 0.70 D when using the AK in the three groups. CONCLUSIONS The association between the magnitude of the keratometric parameters and their measurement errors suggests that limits should be based on disease severity to ensure reliable detection of progressive keratoconus. Further studies are, however, required.
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Affiliation(s)
- Ingemar Gustafsson
- Department of Clinical Sciences Lund, Ophthalmology, Lund University, Skane University Hospital, Lund, Sweden
| | - Anders Bergström
- Department of Clinical Sciences Lund, Ophthalmology, Lund University, Skane University Hospital, Lund, Sweden
| | | | - Anders Ivarsen
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
| | - Jesper Hjortdal
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
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Robust keratoconus detection with Bayesian network classifier for Placido-based corneal indices. Cont Lens Anterior Eye 2019; 43:366-372. [PMID: 31866403 DOI: 10.1016/j.clae.2019.12.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 12/03/2019] [Accepted: 12/06/2019] [Indexed: 02/05/2023]
Abstract
PURPOSE To evaluate in a sample of normal and keratoconic eyes a simple Bayesian network classifier for keratoconus identification that uses previously developed topographic indices, calculated directly from the digital analysis of the Placido ring images. METHODS A comparative study was performed on a total of 60 eyes from 60 patients (age 20-60 years) from the Department of keratoconus of INVISION Ophthalmology clinic (Almería, Spain). Patients were divided into two groups depending on their preliminary diagnosis based on the classical topographic criteria: a control group without topographic alteration (30 eyes) and a keratoconus group (30 eyes). The keratoconus group included all grades except grade IV with excessively distorted corneal topography. All cases were examined using the CSO topography system (CSO, Firenze, Italy), and primary corneal Placido-indices were computed, as described in literature. Finally, a classifier was built by fitting a conditional linear Gaussian Bayesian network to the data, using the 5- and 10-fold cross-validation. For comparison, the original data were perturbed with random white noise of different magnitude. RESULTS The naïve Bayes classifier showed perfect discrimination ability among normal and keratoconic corneas, with 100% of sensibility and specificity, even in the presence of a very significant noise. CONCLUSIONS The Bayesian network classifiers are highly accurate and proved a stable screening method to assist ophthalmologists with the detection of keratoconus, even in the presence of noise or incomplete data. This algorithm is easily implemented for any Placido topographic system.
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Assessment of the Association between In Vivo Corneal Morphogeometrical Changes and Keratoconus Eyes with Severe Visual Limitation. J Ophthalmol 2019; 2019:8731626. [PMID: 31662899 PMCID: PMC6778916 DOI: 10.1155/2019/8731626] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/06/2019] [Accepted: 08/23/2019] [Indexed: 02/06/2023] Open
Abstract
Assessing changes suffered by the cornea as keratoconus progresses has proven to be vital for this disease diagnosis and treatment. This study determines the corneal biometric profile in eyes considered as affected by keratoconus (KC) showing severe visual limitation, by means of in vivo 3D modelling techniques. This observational case series study evaluated new objective indices in 50 healthy and 30 KC corneas, following a validated protocol created by our research group, which has been previously used for diagnosis and characterization of KC in asymptomatic (preclinical) and mild visually impaired eyes. Results show a statistically significant reduction of corneal volume and an increase of total corneal area in the severe KC group, being anterior and posterior corneal surfaces minimum thickness points the best correlated parameters, although with no discrimination between groups. Receiving operator curves were used to determine sensitivity and specificity of selected indices, being anterior and posterior apex deviations the ones which reached the highest area under the curve, both with very high sensitivity (96.7% and 90%, respectively) and specificity (94.0% and 99.9%, respectively). The results suggest that once severe visual loss appears, anterior corneal topography should be considered for a more accurate diagnosis of clinical KC, being anterior apex deviation the key metric discriminant. This study can be a useful tool for KC classification, helping doctors in diagnosing severe cases of the disease, and can help to characterize corneal changes that appear when severe KC is developed and how they relate with vision deterioration.
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Severinsky B, Fadel D, Davelman J, Moulton E. Effect of Scleral Lenses on Corneal Topography in Keratoconus: A Case Series of Cross-Linked Versus Non-Cross-Linked Eyes. Cornea 2019; 38:986-991. [PMID: 31180339 DOI: 10.1097/ico.0000000000002008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE To evaluate the changes in anterior corneal topography induced by short-time wear of scleral contact lenses (SLs) in keratoconic subjects with and without a history of corneal cross-linking (CXL). METHODS Nine keratoconic patients (14 eyes) were fitted with 18.5 mm SLs for optical rehabilitation. Subjects were divided into 2 groups: 7 eyes without a history of CXL (Non-CXL group) and 7 with a history of CXL (CXL group). Corneal topography was performed at baseline and after 2 and 5 hours of lens wear. The differences for simulated flat (Kflat), steep (Ksteep) and maximal (Kmax) corneal curvatures, central corneal astigmatism (CCA), and central cornea thickness were evaluated. RESULTS No statistically significant difference was detected between Non-CXL and CXL groups in any of these measures. Statistically significant flattening was detected in Ksteep Repeated measures analysis of variance ([RM-ANOVA), F (2,24) = 11.32, P < 0.0001], CCA [RM-ANOVA, F (2,24) = 15.34, P < 0.0001], and Kmax [RM-ANOVA, F (2,24) = 19.10, P < 0.0001). From baseline to 5 hours of SL wear, Ksteep decreased on average from 53.1 to 52.4 D, Kmax decreased from 56.7 to 55.8 D, and CCA decreased from 7.2 to 6.3 D. Kmax showed a trend toward more flattening in the Non-CXL group. Central cornea thickness showed significant thickening over time from baseline (451 μm) to 5 hours (458 μm) of SL wear [RM-ANOVA, F (1,12) = 319.3, P < 0.0001]. CONCLUSIONS Short-term scleral lens wear in keratoconic patients may cause flattening of the anterior cornea. A history of CXL treatment does not guarantee corneal shape stability after scleral lens wear. Practitioners should be aware of these changes because scleral lens wear may mask the signs of keratoconus progression.
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Affiliation(s)
- Boris Severinsky
- Emory Eye Center, Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA
| | - Daddi Fadel
- Il Punto di Vista, Private Practice, Rome, Italy
| | - Jenya Davelman
- Department of Ophthalmology, Hadassah Medical Center (HMC), Hebrew University, Jerusalem, Israel
| | - Eric Moulton
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA.,Department of Anesthesiology, Critical Care and Pain Medicine, Boston, MA
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Pellucid marginal degeneration: Detection, discrimination from other corneal ectatic disorders and progression. Cont Lens Anterior Eye 2019; 42:341-349. [DOI: 10.1016/j.clae.2018.11.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/07/2018] [Accepted: 11/15/2018] [Indexed: 02/07/2023]
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Abstract
Supplemental Digital Content is Available in the Text. Purpose: To map the publication trends in and explore hotspots of keratoconus research. Methods: A bibliometric analysis based on the Web of Science Core Collection was conducted to investigate the publication trends in research related to keratoconus. The records extracted were analyzed, and a knowledge map was constructed using VOSviewer v.1.6.10 to visualize the annual publication number, distribution of countries, international collaborations, author productivity, source journals, intellectual base, and research hotspots in the field of keratoconus. Results: In total, 3194 peer-reviewed publications on keratoconus published between 2009 and 2018 were retrieved, and the annual research output increased with time. The United States ranked the highest among the countries with the most publications, and Tehran University of Medical Sciences was the most active institution. JL Alio contributed to the most number of publications on keratoconus, and Cornea was the most prolific journal publishing keratoconus research. The top cited references mainly focused on corneal collagen cross-linking. The keywords formed 6 clusters: 1) pathogenesis of keratoconus, 2) corneal collagen cross-linking, 3) management for early-stage keratoconus, 4) corneal parameter measurement, 5) surgical treatment of keratoconus, and 6) corneal biomechanics-related research. Conclusions: On the basis of the data extracted from the Web of Science Core Collection, the quantity and quality of publications on keratoconus were assessed using bibliometric techniques. The cited references and research hotspots could provide insights into keratoconus research as well as valuable information to cornea specialists for performing research in this field and discovering potential collaborators.
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Analysis of Intrasession Repeatability of Ocular Aberrometric Measurements and Validation of Keratometry Provided by a New Integrated System in Mild to Moderate Keratoconus. Cornea 2019; 38:1097-1104. [DOI: 10.1097/ico.0000000000002034] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Issarti I, Consejo A, Jiménez-García M, Hershko S, Koppen C, Rozema JJ. Computer aided diagnosis for suspect keratoconus detection. Comput Biol Med 2019; 109:33-42. [DOI: 10.1016/j.compbiomed.2019.04.024] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/11/2019] [Accepted: 04/20/2019] [Indexed: 01/03/2023]
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Assessment of corneal biomechanical parameters in healthy and keratoconic eyes using dynamic bidirectional applanation device and dynamic Scheimpflug analyzer. J Cataract Refract Surg 2019; 45:778-788. [PMID: 30902432 DOI: 10.1016/j.jcrs.2018.12.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 12/13/2018] [Accepted: 12/16/2018] [Indexed: 01/03/2023]
Abstract
PURPOSE To investigate corneal biomechanical parameters in healthy and keratoconic eyes using the Ocular Response Analyzer dynamic bidirectional applanation device (ORA) and the Corvis ST dynamic Scheimpflug analyzer (CST). SETTING Department of Ophthalmology, Carl Gustav Carus University Hospital Dresden, Germany. DESIGN Prospective, monocentric, case-control study. METHODS Corneal biomechanical parameters were obtained in 60 eyes of 60 healthy participants (Group I) and 60 eyes of 60 keratoconus patients (Group II) with different grades of severity using the ORA and the CST. Participants were matched by age (Group I: 38.3 years ± 12.8 [SD], Group II: 37.3 ± 11.2 years) and intraocular pressure (Group I: 13.7 ± 1.7 mm Hg, Group II: 13.6 ± 1.5 mm Hg). RESULTS For the ORA, the receiver operating characteristic curve analysis showed an area under the curve (AUC) of 0.950 for the keratoconus score, a sensitivity of 87% and a specificity of 93%. The AUC for the corneal resistant factor and corneal hysteresis was 0.930 and 0.868 with a sensitivity of 87% and a specificity of 87%, and sensitivity of 80% and a specificity of 80%, respectively. For the CST, the corneal biomechanical index showed the highest AUC (0.977) with a sensitivity of 97% and a specificity of 98%. The AUC of integrated radius (0.974; 90% sensitivity, 93% specificity) was followed by maximum inverse radius (0.962; 92% sensitivity, 93% specificity). Most parameters were able to discriminate healthy eyes from different keratoconus stages and early stages of keratoconus from moderate stages. CONCLUSION Both devices allowed for good differentiation between healthy eyes and keratoconic eyes and between different severity grades of keratoconus. Several parameters of ORA and CST revealed high sensitivity and specificity values for keratoconus detection.
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