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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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Ambrósio R, Salomão MQ, Barros L, da Fonseca Filho JBR, Guedes J, Neto A, Machado AP, Lopes BT, Sena N, Esporcatte LPG. Multimodal diagnostics for keratoconus and ectatic corneal diseases: a paradigm shift. EYE AND VISION (LONDON, ENGLAND) 2023; 10:45. [PMID: 37919821 PMCID: PMC10623885 DOI: 10.1186/s40662-023-00363-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 10/14/2023] [Indexed: 11/04/2023]
Abstract
Different diagnostic approaches for ectatic corneal diseases (ECD) include screening, diagnosis confirmation, classification of the ECD type, severity staging, prognostic evaluation, and clinical follow-up. The comprehensive assessment must start with a directed clinical history. However, multimodal imaging tools, including Placido-disk topography, Scheimpflug three-dimensional (3D) tomography, corneal biomechanical evaluations, and layered (or segmental) tomography with epithelial thickness by optical coherence tomography (OCT), or digital very high-frequency ultrasound (dVHF-US) serve as fundamental complementary exams for measuring different characteristics of the cornea. Also, ocular wavefront analysis, axial length measurements, corneal specular or confocal microscopy, and genetic or molecular biology tests are relevant for clinical decisions. Artificial intelligence enhances interpretation and enables combining such a plethora of data, boosting accuracy and facilitating clinical decisions. The applications of diagnostic information for individualized treatments became relevant concerning the therapeutic refractive procedures that emerged as alternatives to keratoplasty. The first paradigm shift concerns the surgical management of patients with ECD with different techniques, such as crosslinking and intrastromal corneal ring segments. A second paradigm shift involved the quest for identifying patients at higher risk of progressive iatrogenic ectasia after elective refractive corrections on the cornea. Beyond augmenting the sensitivity to detect very mild (subclinical or fruste) forms of ECD, ectasia risk assessment evolved to characterize the inherent susceptibility for ectasia development and progression. Furthermore, ectasia risk is also related to environmental factors, including eye rubbing and the relational impact of the surgical procedure on the cornea.
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Affiliation(s)
- Renato Ambrósio
- Department of Ophthalmology, Federal University the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil.
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil.
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil.
- Rio Vision Hospital, Rua Prudente de Moraes, 1276, Rio de Janeiro, RJ, 22420-042, Brazil.
- Brazilian Study Group of Artificial Intelligence and Corneal Analysis - BrAIN, Rio de Janeiro & Maceió, Brazil.
| | - Marcella Q Salomão
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
- Rio Vision Hospital, Rua Prudente de Moraes, 1276, Rio de Janeiro, RJ, 22420-042, Brazil
- Brazilian Study Group of Artificial Intelligence and Corneal Analysis - BrAIN, Rio de Janeiro & Maceió, Brazil
- Benjamin Constant Institute, Rio de Janeiro, Brazil
| | - Lorena Barros
- Department of Ophthalmology, Federal University the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
- Rio Vision Hospital, Rua Prudente de Moraes, 1276, Rio de Janeiro, RJ, 22420-042, Brazil
| | - João Batista R da Fonseca Filho
- Department of Ophthalmology, Federal University the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
- Rio Vision Hospital, Rua Prudente de Moraes, 1276, Rio de Janeiro, RJ, 22420-042, Brazil
| | - Jaime Guedes
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
| | - Alexandre Neto
- Department of Ophthalmology, Federal University the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
| | - Aydano P Machado
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
- Brazilian Study Group of Artificial Intelligence and Corneal Analysis - BrAIN, Rio de Janeiro & Maceió, Brazil
- Computing Institute, Federal University of Alagoas, Maceió, Brazil
| | - Bernardo T Lopes
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
- Brazilian Study Group of Artificial Intelligence and Corneal Analysis - BrAIN, Rio de Janeiro & Maceió, Brazil
- Department of Ophthalmology, Alder Hey Children's Hospital, Liverpool, L12 2AP, UK
| | - Nelson Sena
- Department of Ophthalmology, Federal University the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
- Rio Vision Hospital, Rua Prudente de Moraes, 1276, Rio de Janeiro, RJ, 22420-042, Brazil
| | - Louise Pellegrino Gomes Esporcatte
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
- Rio Vision Hospital, Rua Prudente de Moraes, 1276, Rio de Janeiro, RJ, 22420-042, Brazil
- Brazilian Study Group of Artificial Intelligence and Corneal Analysis - BrAIN, Rio de Janeiro & Maceió, Brazil
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Schümmer L, Kreps EO, Pesudovs K, Berwouts J, Estramil N, Mathysen DGP, Rozema JJ. Investigating the Link Between Visual Quality and Vision-Related Quality of Life in Patients With Keratoconus. Cornea 2023; 42:1280-1285. [PMID: 36729659 DOI: 10.1097/ico.0000000000003200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 10/15/2022] [Indexed: 02/03/2023]
Abstract
PURPOSE The purpose of the study was to investigate the optical and visual determinants of vision-related quality of life (VR-QoL) in patients with keratoconus. METHODS A cross-sectional case-control study was conducted at the Department of Ophthalmology, Antwerp University Hospital, Belgium. Patients previously diagnosed with keratoconus and healthy emmetropic or ametropic volunteers were included. Patients younger than 18 years, with ametropia of more than ±10 D, or with a history of corneal surgery or relevant ocular comorbidity limiting visual acuity were excluded. Assessment included autorefraction, high-contrast visual acuity testing, corneal imaging, intraocular straylight analysis, contrast sensitivity, aberrometry, and the National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25). The Rasch-modified visual functioning scale (VFS) and socio-emotional scale were used to quantify VR-QoL. Stepwise linear regression was used to investigate the association between the clinical variables and VR-QoL. RESULTS Seventy-seven patients with keratoconus (77 pairs of eyes) and 77 age-matched and sex-matched controls were included in the study. The scores on the VFS and the SES were significantly lower in patients with keratoconus compared with controls ( P < 0.001). Higher-order and lower-order aberrations, high-contrast visual acuity, and contrast sensitivity were poorer in patients with keratoconus ( P < 0.001). Bivariate analyses showed that spectacle-corrected high-contrast visual acuity, higher spatial frequency contrast sensitivity, and higher-order aberration metrics were strong predictors of SES ( P < 0.001) and of VFS ( P < 0.001). Higher-order aberration of the worse eye was the strongest predictor for both SES (b = 0.310, P < 0.001) and VFS (b = 0.638, P < 0.001) on stepwise regression. Contrast sensitivity was not included in the stepwise regression because of insufficient data in the keratoconus group (33/77 patients; 42.9%). CONCLUSIONS Both higher and lower aberration showed a strong correlation with VR-QoL, surpassing high-contrast visual acuity. These findings underline the importance of visual quality measures within keratoconus research and clinical care.
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Affiliation(s)
- Laura Schümmer
- Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium
| | - Elke O Kreps
- Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium
| | - Konrad Pesudovs
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, New South Wales, Australia
| | - Jesse Berwouts
- Research and Development Department, Christian Health Insurance Fund, Ghent, Belgium
| | - Natalia Estramil
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium; and
| | - Danny G P Mathysen
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium; and
- Visual Optics Lab Antwerp, Department of Medicine and Health Science, University of Antwerp, Wilrijk, Belgium
| | - Jos J Rozema
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium; and
- Visual Optics Lab Antwerp, Department of Medicine and Health Science, University of Antwerp, Wilrijk, Belgium
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Greenstein SA, Yu AS, Wawrzusin P, Ando A, Chung D, Garvey N, Su B, Hersh PS, Gelles JD. Correlation of Manifest Refraction and Simulated Keratometry to Tomography Characteristics in Patients With Keratoconus. Eye Contact Lens 2023; 49:428-432. [PMID: 37638876 DOI: 10.1097/icl.0000000000001024] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/25/2023] [Indexed: 08/29/2023]
Abstract
OBJECTIVES To report on baseline refractive and keratometric values and their correlation with tomographic characteristics of eyes with keratoconus (KC). METHODS Retrospective chart review of patients treated in a single-center cornea and refractive surgery practice. Baseline topographic measurements were reviewed for 1,012 keratoconic eyes of 586 patients between 2008 and 2018. The manifest refraction, thinnest pachymetry (P thin ), corneal astigmatism (K astig ), and the maximum (K max ), steep (K steep ), flat (K flat ), and mean (K mean ) keratometry were analyzed. The location of K max (x, y) was used to determine central (<1 mm), paracentral (1-3 mm), pericentral (3-5 mm), or peripheral (>5 mm) cone locations. RESULTS In the entire cohort, the mean manifest sphere was -2.2±4.4 diopters (D) and the cylinder was -3.2±2.3 D. In total, 48.6% of patients had against the rule (ATR) manifest astigmatism (M astig ). The average K astig was 3.8±2.7 D, and unlike the manifest axis, 50.2% of patients had with the rule (WTR) K astig . Patients with a K max less than 50 D had an M astig of -1.9±1.6 D, 45.9% of which was ATR M astig . With respect to baseline tomography measurements, K max , K steep , K flat , and K mean were 58.0±9.4, 50.6±6.5, 46.8±5.9, and 48.6±6.1 D, respectively. There was a weak correlation between K max and simulated keratometry (K steep , K flat , and K mean ) for patients with a K max less than 60 D. CONCLUSIONS Simulated keratometry is poorly correlated with KC severity until the disease is more severe. M astig ≥2 D and ATR M astig were correlated with KC at all levels of severity. M astig ≥2 D and ATR M astig may serve as a simple, inexpensive, and widely available indicator for topographic analysis to identify possible KC and suggest further workup; however, further prospective studies are needed to confirm its utility.
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Affiliation(s)
- Steven A Greenstein
- Cornea and Laser Eye Institute (S.A.G., A.S.Y., A.A., D.C., N.G., B.S., P.S.H., J.D.G.) Teaneck, NJ; and Department of Ophthalmology (S.A.G., P.W., P.S.H., J.D.G.), Rutgers New Jersey Medical School, Newark, NJ
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Abstract
PURPOSE To enumerate the various diagnostic modalities used for keratoconus and their evolution over the past century. METHODS A comprehensive literature search including articles on diagnosis on keratoconus were searched on PUBMED and summarized in this review. RESULTS Initially diagnosed in later stages of the disease process through clinical signs and retinoscopy, the initial introduction of corneal topography devices like Placido disc, photokeratoscopy, keratometry and computer-assisted videokeratography helped in the earlier detection of keratoconus. The evolution of corneal tomography, initially with slit scanning devices and later with Scheimpflug imaging, has vastly improved the accuracy and detection of clinical and sub-clinical disease. Analyzing the alteration in corneal biomechanics further contributed to the earlier detection of keratoconus even before the tomographic changes became evident. Anterior segment optical coherence tomography has proven to be a helpful adjuvant in diagnosing keratoconus, especially with epithelial thickness mapping. Confocal microscopy has helped us understand the alterations at a cellular level in keratoconic corneas. CONCLUSION Thus, the collective contribution of the various investigative modalities have greatly enhanced earlier and accurate detection of keratoconus, thus reducing the disease morbidity.
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Affiliation(s)
- Akhil Bevara
- Department of Cornea and Anterior segment, Cornea Institute, L V Prasad Eye Institute, Hyderabad, India
| | - Pravin K Vaddavalli
- Department of Cornea and Anterior segment, Cornea Institute, L V Prasad Eye Institute, Hyderabad, India
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Koh S, Inoue R, Iwamoto Y, Mihashi T, Soma T, Maeda N, Nishida K. Comparison of Ocular Wavefront Aberration Measurements Obtained Using Two Hartmann-Shack Wavefront Aberrometers. Eye Contact Lens 2023; 49:98-103. [PMID: 36729105 DOI: 10.1097/icl.0000000000000965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 11/03/2022] [Indexed: 02/03/2023]
Abstract
OBJECTIVES To assess agreement between measurements of ocular wavefront aberrations obtained using the Pentacam AXL Wave (Oculus Optikgeräte GmbH) (Aberrometer A) and KR-1W (Topcon Corp) (Aberrometer B), both of which are based on the Hartmann-Shack principle. METHODS In this prospective case-control study, ocular wavefront aberrations measurements were obtained using both aberrometers in patients with keratoconus (KC) and control participants. Ocular wavefront aberrations were measured through the natural pupil without dilation using both devices in a dark room. For both aberrometers, accommodation was inhibited by automatically adding fogging. The individual Zernike coefficients from the second to fourth order were compared between the two aberrometers for a 4-mm pupil diameter. RESULTS Twenty-six KC and 29 control eyes were assessed. Statistically significant correlations ( P <0.05) were observed for all Zernike coefficients, except for Z 4-2 in the control group. Bland-Altman analysis indicated good agreement between aberrometers and no statistically significant differences in the control group. However, in the KC group, patterns of proportional error were observed in vertical coma Z 3-1 (r=0.338, P =0.008), trefoil Z 4-4 (r=0.701, P =0.003), secondary astigmatism Z 4-2 (r=0.348, P =0.025), and spherical aberrations Z 40 (r=0.407, P =0.012). CONCLUSIONS The Zernike coefficient values measured by the two aberrometers were well correlated in the control and KC groups. However, in eyes with KC, Aberrometer B tended to present greater values in several Zernike coefficients than Aberrometer A, suggesting that wavefront measurements obtained using the two aberrometers are not interchangeable in patients with KC.
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Affiliation(s)
- Shizuka Koh
- Department of Innovative Visual Science (S.K., R.I.), Osaka University Graduate School of Medicine, Osaka, Japan; Department of Ophthalmology (S.K., Y.I., T.S., K.N.), Osaka University Graduate School of Medicine, Osaka, Japan; SEED CO. (R.I.), LTD., Tokyo, Japan; and Department of Orthoptics (T.M.), Faculty of Medical Technology, Teikyo University, Tokyo, Japan
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Salman A, Kailani O, Marshall J, Ghabra M, Balamoun AA, Darwish TR, Badla AA, Alhaji H. Evaluation of Anterior and Posterior Corneal Higher Order Aberrations for the Detection of Keratoconus and Suspect Keratoconus. Tomography 2022; 8:2864-2873. [PMID: 36548532 PMCID: PMC9782471 DOI: 10.3390/tomography8060240] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/20/2022] [Accepted: 11/28/2022] [Indexed: 12/07/2022] Open
Abstract
AIM To investigate the application of anterior and posterior corneal higher-order aberrations (HOAs) in detecting keratoconus (KC) and suspect keratoconus (SKC). METHOD A retrospective, case-control study evaluating non-ectatic (normal) eyes, SKC eyes, and KC eyes. The Sirius Scheimpfug (CSO, Italy) analyses was used to measure HOAs of the anterior and posterior corneal surfaces. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated. RESULTS Two-hundred and twenty eyes were included in the analysis (normal n = 108, SKC n = 42, KC n = 70). Receiver operating characteristic (ROC) curve analysis revealed a high predictive ability for anterior corneal HOAs parameters: the root mean square (RMS) total corneal HOAs, RMS trefoil, and RMS coma to detect keratoconus (AUC > 0.9 for all). RMS Coma (3, ±1) derived from the anterior corneal surface was the parameter with the highest ability to discriminate between suspect keratoconus and normal eyes (AUC = 0.922; cut-off > 0.2). All posterior corneal HOAs parameters were unsatisfactory in discriminating between SKC and normal eyes (AUC < 0.8 for all). However, their ability to detect KC was excellent with AUC of >0.9 for all except RMS spherical aberrations (AUC = 0.846). CONCLUSIONS Anterior and posterior corneal higher-order aberrations can differentiate between keratoconus and normal eyes, with a high level of certainty. In suspect keratoconus disease, however, only anterior corneal HOAs, and in particular coma-like aberrations, are of value. Corneal aberrometry may be of value in screening for keratoconus in populations with a high prevalence of the disease.
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Affiliation(s)
- Abdelrahman Salman
- Department of Ophthalmology, Tishreen University, Latakia P.O. Box 25, Syria
- Correspondence:
| | - Obeda Kailani
- King’s College Hospital NHS Foundation Trust, London SE5 9RS, UK
| | - John Marshall
- Institute of Ophthalmology, University College London in Association with Moorfield Eye Hospital, London WC1E 6BT, UK
| | - Marwan Ghabra
- Whipps Cross University Hospital, Leytonstone, London E11 1NR, UK
| | | | - Taym R. Darwish
- Department of Ophthalmology, Tishreen University, Latakia P.O. Box 25, Syria
| | - Abdul Aziz Badla
- Department of Ophthalmology, Suliman Al-Habib Hospital, Dubai 41516, United Arab Emirates
| | - Hala Alhaji
- Department of Ophthalmology, Tishreen University, Latakia P.O. Box 25, Syria
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Li J, Xue C, Zhang Y, Liu C, Du J, Li Y, Liu J, Wei S, Wu Z. Diagnostic value of corneal higher-order aberrations in keratoconic eyes. Int Ophthalmol 2022; 43:1195-1206. [PMID: 36149622 DOI: 10.1007/s10792-022-02518-9] [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: 07/31/2022] [Accepted: 09/11/2022] [Indexed: 11/24/2022]
Abstract
PURPOSE This study aimed to investigate the diagnostic value of corneal anterior, posterior, and total higher-order aberrations in keratoconic eyes. METHODS We enrolled 94 patients (152 eyes) with mild keratoconus (Group 1), 64 patients (101 eyes) with moderate keratoconus (Group 2), and 32 patients (52 eyes) with advanced keratoconus (Group 3) according to the Amsler-Krumeich classification system; 99 healthy controls (197 normal eyes) were likewise enrolled. Anterior, posterior, and total corneal higher-order aberrations were assessed using a rotating Scheimpflug camera. The 3rd-order and 4th-order root-mean-square values were calculated for higher-order aberrations, including coma, spherical, and trefoil aberrations. Differences between keratoconic and normal eyes were analyzed using Kruskal-Wallis tests. Receiver operating characteristic curves were evaluated for the keratoconus and control groups. RESULTS The differences in coma 90, coma, trefoil, and spherical aberrations, as well as 3rd-order and 4th-order root-mean-square values, were statistically significant between the keratoconus and control groups for all anterior, posterior, and corneal aberrations. The absolute values of these higher-order aberrations were higher in the keratoconus groups than in the control group and increased with keratoconus severity in Groups 1-3. Coma and 3rd-order RMS values showed excellent sensitivity and specificity for discriminating between normal and keratoconus eyes for all anterior, posterior, and corneal aberrations. CONCLUSION Coma aberrations and 3rd-order root-mean-square values may be valuable for diagnosing keratoconus. Combining these data with topography information may enable the effective and efficient detection of keratoconus in the future.
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Affiliation(s)
- Jing Li
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Chao Xue
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin, China
- Nankai University Affiliated Eye Hospital, Nankai University, Tianjin, China
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, 300020, China
| | - Yaohua Zhang
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Chunlei Liu
- Refractive Surgery Department, Shenyang Aier Eye Hospital, Shenyang, 110001, China
| | - Jing Du
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Yong Li
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Jianguo Liu
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Shengsheng Wei
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China.
| | - Zhiqing Wu
- Department of Ophthalmology, Hospital of Shaanxi Normal University, Xi'an, China
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Koh S, Inoue R, Maeno S, Mihashi T, Maeda N, Jhanji V, Nishida K. Characteristics of Higher-Order Aberrations in Different Stages of Keratoconus. Eye Contact Lens 2022; 48:256-260. [PMID: 35333804 DOI: 10.1097/icl.0000000000000897] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/07/2022] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To characterize higher-order aberrations (HOAs) in clinical and subclinical keratoconus (KC). METHODS The study included 33, 36, and 26 patients with clinical, topographic (no clinical signs), and pretopographic (normal topography and no clinical signs) KC and 30 controls. Ocular and corneal HOAs for the 4-mm pupils were measured using a wavefront sensor and expanded up to the sixth order of Zernike polynomials. The magnitudes of trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration were calculated via Zernike vector analysis and used as HOA parameters along with total HOAs. Area under the receiver operating characteristic curve (AUROC) values for each wavefront parameter for pretopographic KC were compared. RESULTS Control eyes and eyes with pretopographic KC had significantly lower ocular or corneal total HOAs and Zernike vector terms than those with clinical KC and topographic KC, except for ocular tetrafoil between topographic KC and pretopographic KC and spherical aberration among all groups. The AUROCs for corneal total HOAs and corneal coma for pretopographic KC and control eyes were 0.781 (100% sensitivity and 47% specificity) and 0.735 (73% sensitivity and 73% specificity), respectively. CONCLUSION Corneal total HOAs and corneal coma exhibited a potential ability to discriminate pretopographic KC from normal control eyes.
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Affiliation(s)
- Shizuka Koh
- Departments of Innovative Visual Science (S.K., R.I.), and Ophthalmology (S.K., S.M., N.M., K.N.), Osaka University Graduate School of Medicine, Osaka, Japan; SEED Co, Ltd (RI), Tokyo, Japan; Department of Orthoptics (T.M.), Faculty of Medical Technology, Teikyo University, Tokyo, Japan; and Department of Ophthalmology (V.J.), University of Pittsburgh School of Medicine, Pittsburgh, PA
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Yekta A, Hashemi H, Ostadimoghaddam H, Hadizadeh M, Rafati S, Doostdar A, Nabovati P, Sadoughi MM, Khabazkhoob M. Anterior and posterior corneal higher-order aberrations in early diagnosis and grading of keratoconus. Clin Exp Optom 2022; 106:263-270. [PMID: 35109771 DOI: 10.1080/08164622.2022.2033602] [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: 10/19/2022] Open
Abstract
CLINICAL RELEVANCE Evaluation of corneal higher-order aberrations can be used clinically to diagnose early cases of keratoconus as well as to classify the severity of keratoconus. BACKGROUND To investigate the anterior and posterior corneal higher-order aberrations (HOAs) up to the sixth order and their ability to identify early keratoconus (KCN) as well as differentiate different severities of KCN using cross-validation analysis. METHODS This prospective cross-sectional comparative study was performed at a tertiary eye hospital in Tehran, Iran, in 2019. The study sample consisted of 95 eyes of 95 patients with KCN and 53 eyes of 53 normal individuals. The eyes with KCN were classified into three groups based on the Amsler-Krumeich classification system: group 1 (mild KCN), group 2 (moderate KCN), and group 3 (severe KCN). Corneal wavefront analysis was performed using Pentacam HR. RESULTS Based on the magnitude of AUC, posterior vertical secondary coma (Z5-1) had an excellent discriminant ability (AUC: 0.91) and anterior vertical coma (Z3-1) and anterior vertical secondary coma (Z5-1) had a good discriminant ability (0.8 < AUC < 0.89) for differentiating eyes with mild KCN from normal eyes. The anterior and posterior primary spherical aberrations (Z4°) had an excellent ability (AUC > 0.9), and anterior secondary spherical aberration (Z6°) had a good ability (AUC: 0.83) for differentiating moderate from mild KCN. In the differentiation of severe from moderate KCN, anterior and posterior primary aspherical aberrations (Z4°) had a good AUC value (AUC > 0.8). CONCLUSION Coma-like aberrations had a good discriminant ability between normal eyes and eyes with mild KCN. Spherical aberrations showed a good ability for differentiating between different stages of KCN. The cut-off values reported in this study can be used for early detection of KCN as well as classification of KCN severity.
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Affiliation(s)
- Abbasali Yekta
- Department of Optometry, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hassan Hashemi
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | - Hadi Ostadimoghaddam
- Refractive Errors Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohsen Hadizadeh
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | - Shokoofeh Rafati
- Rehabilitation Research Center, Department of Optometry, Iran University of Medical Sciences, Tehran, Iran
| | - Asgar Doostdar
- Rehabilitation Research Center, Department of Optometry, Iran University of Medical Sciences, Tehran, Iran
| | - Payam Nabovati
- Rehabilitation Research Center, Department of Optometry, Iran University of Medical Sciences, Tehran, Iran
| | | | - Mehdi Khabazkhoob
- Department of Basic Sciences, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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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: 167] [Impact Index Per Article: 83.5] [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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Shiga S, Kojima T, Nishida T, Nakamura T, Ichikawa K. Evaluation of CorvisST biomechanical parameters and anterior segment optical coherence tomography for diagnosing forme fruste keratoconus. Acta Ophthalmol 2021; 99:644-651. [PMID: 33326180 DOI: 10.1111/aos.14700] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/26/2020] [Accepted: 11/10/2020] [Indexed: 11/27/2022]
Abstract
PURPOSE To investigate the utility of biomechanical property measurements using a Scheimpflug-based tonometer (SBT) and/or anterior segment optical coherence tomography (AS-OCT) for diagnosing forme fruste keratoconus (FFK). METHODS In this retrospective interventional case series, 23 eyes with FFK of 23 consecutive patients and 52 eyes of 52 healthy volunteers who visited our keratoconus outpatient clinic were enrolled. Logistic regression analysis was conducted to determine the causal relationship between FFK diagnosis and each parameter. RESULTS When only SBT was used, the corneal stiffness parameter, stiffness parameter A1 (SP-A1) and the corneal velocity at first applanation were selected as explanatory variables, and sensitivity, specificity and area under the receiver operating characteristic curve (AUROC) were 82.9%, 86.9% and 0.938, respectively. When only AS-OCT parameters were used, the posterior corneal asymmetric component and central corneal thickness were selected, and the sensitivity, specificity and AUROC were 82.6%, 94.2% and 0.893, respectively. When parameters from both methods were used, SP-A1 and the posterior corneal asymmetry component derived from Fourier analysis were selected as explanatory variables, and sensitivity, specificity and AUROC were 91.30%, 90.38% and 0.947, respectively. No significant differences in AUROC were observed between diagnoses using each device and the combination of both devices (AS-OCT versus SBT, p = 0.314; integrated parameters versus AS-OCT, p = 0.081; integrated parameters versus SBT, p = 0.234). CONCLUSION Optimization of SBT and AS-OCT parameters allowed for the diagnosis of FFK at a clinically usable level. Forme fruste keratoconus (FFK) diagnosis integrating biomechanical properties with AS-OCT showed no superiority compared to diagnosis based on a single device.
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Affiliation(s)
| | - Takashi Kojima
- Japanese Red Cross Gifu Hospital Gifu Japan
- Department of Ophthalmology Keio University School of Medicine Tokyo Japan
- Nagoya Eye Clinic Nagoya Japan
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Roszkowska AM, Alessandrello F, Waśniewska M, Tropeano A, Gargano R, Aragona P. Is keratoconus associated to thyroid diseases? Assessment of the corneal parameters in patients with congenital hypothyroidism. Eur J Ophthalmol 2021; 32:31-35. [PMID: 34399598 DOI: 10.1177/11206721211039946] [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: 11/16/2022]
Abstract
PURPOSE To investigate the association between keratoconus and congenital hypothyroidism (CH). PATIENTS AND METHODS Patients were enrolled in this study and divided into two groups. The first group comprised 31 subjects (11M:20F) with the mean age of 15.2 ± 3.9 years. affected by CH, and the control group was composed by 19 healthy individuals (8M:11F) aged 14.3 ± 4.6 years. All patients underwent complete ophthalmologic examination with visual acuity assessment, refraction, slit lamp examination, and retinoscopy. Corneal parameters were measured using Scheimpflug camera (Pentacam® Oculus, Germany). The main outcome measures considered for evaluation were: average corneal curvature (K), central corneal thickness (CCT), anterior elevation and posterior elevation at the thinnest point, corneal volume (CV), anterior chamber depth (ACD), and anterior chamber volume (ACV). Additionally, data from Belin/Ambrosio Enhanced Ectasia Display (BAD) and the high order aberrations were evaluated. Kolmogorov-Smirnov test was used to verify the Gaussian distribution, the comparison between the controls and cases group was performed by Mann-Whitney nonparametric test. A p value less than 0.05 was considered to be statistically significant. The odds ratio was performed in order to quantify the relationship between the congenital hypothyroidism and abnormal values displayed on front BAD. RESULTS The significant difference in the refractive status between both groups was observed. As to examined corneal and anterior chamber parameters no statistical differences were detected. CONCLUSIONS Congenital hypothyroidism diagnosed and treated since the early postnatal life doesn't induce abnormalities of corneal parameters suggestive for keratoconus.
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Affiliation(s)
- Anna M Roszkowska
- Ophthalmology Clinic, Department of Biomedical Sciences, University of Messina, Messina, Italy
| | - Federica Alessandrello
- Ophthalmology Clinic, Department of Biomedical Sciences, University of Messina, Messina, Italy
| | - Małgorzata Waśniewska
- Department of Human Pathology of Child and Adulthood, University of Messina, Messina, Italy
| | - Angelo Tropeano
- Department of Human Pathology of Child and Adulthood, University of Messina, Messina, Italy
| | - Romina Gargano
- Department of Economics, University of Messina, Messina, Italy
| | - Pasquale Aragona
- Ophthalmology Clinic, Department of Biomedical Sciences, University of Messina, Messina, Italy
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Repeatability and Agreement of Wavefront aberrations of Pentacam AXL Wave- a new hybrid topographer and aberrometer with ITrace in healthy eyes. J Cataract Refract Surg 2021; 48:408-416. [PMID: 34393184 DOI: 10.1097/j.jcrs.0000000000000775] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 08/06/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE To assess repeatability and agreement of Pentacam AXL Wave, with iTrace aberrometer. SETTING Narayana Nethralaya, Bangalore, India. DESIGN Prospective ,cross-sectional study. METHODS One hundred eyes of 100 patients underwent three sets of measurements, at a single visit, using Pentacam AXL Wave (Oculus, Germany) and iTrace (Tracey Technologies, USA).Lower-order aberration (LOA), higher-order aberration (HOA), Coma and Spherical Aberrations (SA) were analyzed. Repeatability was assessed using within-subject standard deviation (Sw), test-retest variability (TRT), within-subject coefficient of variation (COV) and Intraclass Correlation Coefficient (ICC). The Bland-Altman analysis was used to assess 95% limits of agreement (LoA) and the correlation coefficient (r) to determine strength of relationship between measurements. RESULTS All measurements with Pentacam AXL Wave had repeatability with an ICC for total ocular aberrations ranging from 0.84 for HOAto 0.92 for LOA and corneal from 0.76 for HOA to 0.86 for LOA The Sw, TRT, COV of all aberrations were significantly lower (better) than those of iTrace (p < 0.001). The mean differences between 2 devices were insignificant for the comparison of all parameters, except for spherical aberration (0.011(0.002571 to 0.02008; P= 0.01). Both devices showed excellent corelations for ocular aberrations (tHOA (P=0.12,LoA= -0.52 to 0.025; r= 0.89); LOA (P=0.14, LoA = -2.71 to 2.61 ; r= 0.96) coma (P=0.27, LoA = -0.11 to 0.12; r= 0.89) and in SA (P=0.01, LoA = -0.09 to 0.07;r=0.97)). CONCLUSIONS The repeatability estimates for wavefront aberrations using Pentacam AXL Wave were significantly better than that using iTrace. Both devices showed excellent corelations for total ocular aberrations.
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Shneor E, Piñero DP, Doron R. Contrast sensitivity and higher-order aberrations in Keratoconus subjects. Sci Rep 2021; 11:12971. [PMID: 34155283 PMCID: PMC8217180 DOI: 10.1038/s41598-021-92396-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/09/2021] [Indexed: 02/05/2023] Open
Abstract
This study analyzes the relationship between contrast-sensitivity and higher-order aberrations (HOA) in mild and subclinical-keratoconus in subjects with good visual-acuity (VA). Keratoconus group (including subclinical-keratoconus) and controls underwent autokeratometry, corneal-tomography, autorefraction and HOA measurement. Contrast-sensitivity was tested using a psychophysical two-alternative forced-choice Gabor patches in three blocks (6, 9, 12 cycles/deg). Controls were compared to the keratoconus group and to a keratoconus subgroup with VA of 0.00 LogMar group ("keratoconus-0.00VA"). Spearman correlation tested association between HOA and contrast-sensitivity. Twenty-two keratoconus subjects (38 eyes: 28 keratoconus, 10 subclinical-keratoconus, 20 keratoconus-0.00VA) and 35 controls were included. There was a significant difference between control and keratoconus, and between control and keratoconus-0.00VA, for keratometry, cylinder, thinnest and central corneal thickness (p < 0.001). Controls showed lower HOA and higher contrast-sensitivity for all spatial-frequencies (p < 0.001). Most HOA were negatively correlated with contrast-sensitivity for all spatial-frequencies for keratoconus group and for 9 and 12 cycles/deg for keratoconus-0.00VA. Keratoconus subjects with good VA showed reduction in contrast-sensitivity and increased HOAs compared to controls. HOA and contrast-sensitivity are inversely correlated in subjects with mild keratoconus despite good VA. This suggests that the main mechanism underlying the decreased vision quality in keratoconus is the increase of HOA.
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Affiliation(s)
- Einat Shneor
- Department of Optometry and Vision Science, Hadassah Academic College, Haniviim St. 37, 9101001, Jerusalem, Israel.
| | - David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Ravid Doron
- Department of Optometry and Vision Science, Hadassah Academic College, Haniviim St. 37, 9101001, Jerusalem, Israel
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Corneal Aberrations in Keratoconus: A Pentacam Scheimpflug Imaging Study. JOURNAL OF CONTEMPORARY MEDICINE 2021. [DOI: 10.16899/jcm.846006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Xu M, Ramirez-Garcia MA, Narang H, Buckley MR, Lerner AL, Yoon G. Individualized Characterization of the Distribution of Collagen Fibril Dispersion Using Optical Aberrations of the Cornea for Biomechanical Models. Invest Ophthalmol Vis Sci 2021; 61:54. [PMID: 32866268 PMCID: PMC7463181 DOI: 10.1167/iovs.61.10.54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The spatial distribution of collagen fibril dispersion has a significant impact on both corneal biomechanical and optical behaviors. The goal of this study was to demonstrate a novel method to characterize collagen fibril dispersion using intraocular pressure (IOP)-induced changes in corneal optical aberrations for individualized finite-element (FE) modeling. Methods The method was tested through both numerical simulations and ex vivo experiments. Inflation tests were simulated in FE models with three assumed patterns of collagen fibril dispersion and experimentally on three rhesus monkey corneas. Geometry, matrix stiffness, and the IOP-induced changes in wavefront aberrations were measured, and the collagen fibril dispersion was characterized. An individualized corneal model with customized collagen fibril dispersion was developed, and the estimated optical aberrations were compared with the measured data. Results For the theoretical investigations, three assumed distributions of fibril dispersion were all successfully characterized. The estimated optical aberrations closely matched the measured data, with average root-mean-square (RMS) differences of 0.29, 0.24, and 0.10 µm for the three patterns, respectively. The overall features of the IOP-induced changes in optical aberrations were estimated for two ex vivo monkey corneas, with average RMS differences of 0.57 and 0.43 µm. Characterization of the fibril dispersion in the third cornea might have been affected by corneal hydration, resulting in an increased RMS difference, 0.8 µm. Conclusions A more advanced corneal model with individualized distribution of collagen fibril dispersion can be developed and used to improve our ability to understand both biomechanical and optical behaviors of the cornea.
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Affiliation(s)
- Mengchen Xu
- Department of Mechanical Engineering, University of Rochester, Rochester, New York, United States
| | - Manuel A Ramirez-Garcia
- Department of Biomedical Engineering, University of Rochester, Rochester, New York, United States
| | - Harshita Narang
- Department of Biomedical Engineering, University of Rochester, Rochester, New York, United States
| | - Mark R Buckley
- Department of Biomedical Engineering, University of Rochester, Rochester, New York, United States
| | - Amy L Lerner
- Department of Mechanical Engineering, University of Rochester, Rochester, New York, United States.,Department of Biomedical Engineering, University of Rochester, Rochester, New York, United States
| | - Geunyoung Yoon
- Flaum Eye Institute, The Institute of Optics, Center for Visual Science, Department of Biomedical Engineering, University of Rochester, Rochester, New York, United States
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Menon R, Menon S, Ajith T. Prevalence of subclinical keratoconus in children presenting with refractive errors: A cross-sectional study. KERALA JOURNAL OF OPHTHALMOLOGY 2021. [DOI: 10.4103/kjo.kjo_103_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Abstract
Ectatic corneal disease (ECD) comprises a group of disorders characterized by progressive thinning and subsequent bulging of the corneal structure. Different phenotypes have been recognized, including keratoglobus, pellucid marginal degeneration (PMD), and keratoconus (KC). Keratoconus has been widely investigated throughout the years, but the advent of laser refractive surgery boosted an immediate need for more knowledge and research about ectatic diseases. This article discusses nomenclature of ectatic disease, etiology and pathogenesis, along with treatment options, with special focus ok KC and forme fruste keratoconus.
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20
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Outcomes of photorefractive keratectomy in patients with posterior corneal steepening. Eye (Lond) 2020; 35:2016-2023. [PMID: 33024325 DOI: 10.1038/s41433-020-01213-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 09/19/2020] [Accepted: 09/23/2020] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To assess post-operative outcomes following photorefractive keratectomy (PRK) in patients with posterior corneal steepening compared to an age, gender and refraction matched control group. METHODS A retrospective matched case-control study that analysed outcomes of PRK in eyes with posterior corneal steepening as shown by the Sirius tomography (Sirius, CSO, Italy), versus normal eyes. Both groups were age, gender and refraction matched. Data collected include: demographic data, pre-operative and post-operative refraction, uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), maximal ablation depth. Inferior-superior ratio, central corneal thickness (CCT), mean posterior keratometry (K), Baiocchi Calossi Versaci index for the front (BCVf) and back (BCVb) cornea, the symmetry index of front (SIf) and back (SIb) corneal curvature were assessed pre- and postoperatively. RESULTS Overall, 89 study eyes and 954 normal myopic eyes were included. Compared to the control group, corneas with posterior steepening demonstrated significantly reduced CDVA (p < 0.0001 and p = 0.007) and lower CCT (p < 0.0001 and p = 0.03), before and following the operation, respectively. Pre-operative BCVf, BCVb, SIf and SIb were significantly higher in corneas with posterior steepening (p < 0.0001) and remained higher following the surgery except for BCVf. Ectasia occurred in one eye (1.1%). The safety and efficacy indices at 12 months were comparable for both groups. CONCLUSION PRK on corneas with posterior steepening results in similar refractive outcomes compared to normal eyes, 1 year following the surgery. Keratectasia is a rare, however a possible complication.
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Ziaei M, Gokul A, Vellara H, Patel DV, McGhee CNJ. Measurement of refractive, wavefront, topographic, and keratometric changes attributable to epithelial removal in keratoconus. Can J Ophthalmol 2020; 56:6-11. [PMID: 32777204 DOI: 10.1016/j.jcjo.2020.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/20/2020] [Accepted: 06/29/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE The corneal epithelium is able to mask topographic and keratometric abnormalities of the underlying Bowman layer in keratoconus, but its contribution to refractive and wavefront parameters has not yet been studied. This study compared the refractive and aberrometric features of the corneal epithelium and Bowman layer in eyes with keratoconus before and after epithelial debridement. METHODS Corneal refractive and wavefront variables were measured in patients with keratoconus undergoing corneal crosslinking-immediately before and after epithelial debridement using a third-generation combined corneal topographer, autorefractor, and aberrometer. RESULTS After epithelial debridement, there were significant changes in spherical equivalent (-1.37 D; p < 0.01) and asphericity (-0.64; p = 0.03). The mean difference in the magnitude of epithelium-induced astigmatism in the 3rd and 5th central millimeter rings was 0.44 ± 3.20 D × 8 and 0.43 ± 2.75 D × 21 (positive cylinder), respectively. Corneal astigmatism axis shifted in the against-the-rule orientation after epithelial debridement. There were no significant changes in any corneal higher-order aberration parameter after epithelial debridement (p > 0.05). CONCLUSIONS In eyes with keratoconus, epithelial debridement increased the magnitude of anterior corneal prolateness and tended to increase astigmatism and shift its axis toward the against-the-rule orientation. This study supports the notion that the corneal epithelium smooths underlying Bowman layer irregularity in keratoconus.
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Affiliation(s)
- Mohammed Ziaei
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand..
| | - Akilesh Gokul
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Hans Vellara
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Dipika V Patel
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Charles N J McGhee
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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Corneal higher-order aberrations after crosslinking and intrastromal corneal ring segments for keratoconus. J Cataract Refract Surg 2020; 46:979-985. [DOI: 10.1097/j.jcrs.0000000000000209] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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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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Classification of Keratoconus Based on Anterior Corneal High-order Aberrations: A Cross-validation Study. Optom Vis Sci 2020; 97:169-177. [PMID: 32168239 DOI: 10.1097/opx.0000000000001489] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE Placido disc-based videokeratography is one of the most extensively used methods for corneal topographic assessments in keratoconus. Anterior corneal wavefront analysis has been demonstrated to be an effective tool to manage keratoconus eyes. However, currently, there is no clinically adequate classification system for keratoconus. PURPOSE The aim of this study was to analyze the usefulness of anterior corneal high-order aberrations in keratoconus classification provided by Placido disc-based videokeratography conducting a cross-validation analysis. METHODS Corneal topography of 70 normal and 77 keratoconic eyes (divided according to the Amsler-Krumeich classification [n = 21, stage 1; n = 30, stage 2; and n = 26, stage 3]) was assessed using Placido disc-based videokeratography (Oculus Keratograph [Oculus Optikgeräte GmbH, Wetzlar, Germany]). Receiver operating characteristic curve analysis was used to compare the mean values of coma, trefoil, tetrafoil, secondary astigmatism, spherical aberration, and coma-like, third-, and fourth-order root mean square (RMS) to calculate cutoff values, sensitivity, and specificity to discriminate between normal and stage 1 keratoconus eyes and between each keratoconus stage after cross-validation analysis. RESULTS All wavefront aberrations were significantly different between the normal and keratoconus groups (P ≤ .01). The coma and third-order RMS values (cutoff values, 0.367 and 0.359 μm, respectively) provide better sensitivity (99 and 100%, respectively) and specificity (100%) to discriminate keratoconus (stage 1) from healthy eyes compared with trefoil, tetrafoil, secondary astigmatism, spherical aberration, and coma-like and fourth-order RMS values (sensitivity >84% and specificity >57%). The coma and third-order RMS values showed the highest specificity (100%) and great sensitivity (90 and 87%, respectively) to differentiate between stages 1 and 2 and good sensitivity (97 and 100%) and specificity (81 and 88%) to differentiate between stages 2 and 3. CONCLUSIONS Anterior corneal high-order aberrations, specifically coma and third-order RMS, could be useful in keratoconus diagnosis and topographical classification. These new cutoff values could improve different stages of keratoconus eyes discrimination.
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Assessment of Visual Quality in Eyes with Forme Fruste Keratoconus and Mild and Moderate Keratoconus Based on Optical Quality Analysis System II Parameters. J Ophthalmol 2020; 2020:7505016. [PMID: 32280532 PMCID: PMC7125474 DOI: 10.1155/2020/7505016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 01/09/2020] [Indexed: 12/03/2022] Open
Abstract
Purpose The study aimed to evaluate the visual quality of forme fruste keratoconus (FFK) and mild and moderate keratoconus by using an optical quality analysis system II (OQAS-II) and to explore the correlation between optical quality parameters and the disease progression. Methods Twenty-one normal eyes, twenty-one FFK eyes, twenty-one mild keratoconus eyes, and twenty-one moderate keratoconus eyes were included in this prospective study. The optical quality parameters, such as object scatter index (OSI), modulation transfer function cutoff (MTF cutoff), strehl ratio (SR), and OQAS-II values at contrasts of 100% (OV-100), 20% (OV-20), and 9% (OV-9), were measured by OQAS-II. The repeatability of these parameters was analyzed by intraclass correlation coefficient (ICC), repeatability coefficient (RC), and coefficient of variation (CVw). Correlations between optical quality parameters and mean central keratometry readings (Kmean) were evaluated. The sensitivity and specificity of the parameters were analyzed using the receiver operating characteristic (ROC). Results All the optical quality parameters among four groups showed good repeatability (all ICC≥0.75). The MTF cutoff, SR, OV-100, OV-20, OV-9 in FFK, mild and moderate keratoconus eyes were significantly lower than those in the normal group (all P < 0.05). The ROC analyses of the MTF cutoff, SR, OV-100, OV-20, and OV-9 showed significant area under the curve (AUC) in discriminating FFK form normal, mild keratoconus from FFK, and moderate keratoconus from mild keratoconus (all P < 0.05). The ROC analyses of the MTF cutoff, SR, OV-100, OV-20, and OV-9 showed significant area under the curve (AUC) in discriminating FFK form normal, mild keratoconus from FFK, and moderate keratoconus from mild keratoconus (all P < 0.05). The ROC analyses of the MTF cutoff, SR, OV-100, OV-20, and OV-9 showed significant area under the curve (AUC) in discriminating FFK form normal, mild keratoconus from FFK, and moderate keratoconus from mild keratoconus (all P < 0.05). The ROC analyses of the MTF cutoff, SR, OV-100, OV-20, and OV-9 showed significant area under the curve (AUC) in discriminating FFK form normal, mild keratoconus from FFK, and moderate keratoconus from mild keratoconus (all P < 0.05). The ROC analyses of the MTF cutoff, SR, OV-100, OV-20, and OV-9 showed significant area under the curve (AUC) in discriminating FFK form normal, mild keratoconus from FFK, and moderate keratoconus from mild keratoconus (all Kmean) were evaluated. The sensitivity and specificity of the parameters were analyzed using the receiver operating characteristic (ROC). r = −0.710, P < 0.05). The ROC analyses of the MTF cutoff, SR, OV-100, OV-20, and OV-9 showed significant area under the curve (AUC) in discriminating FFK form normal, mild keratoconus from FFK, and moderate keratoconus from mild keratoconus (all Conclusion The repeatability of OQAS-II is good in measuring visual quality of normal as well as FFK, mild, and moderate keratoconus. The visual quality of the FFK, mild, and moderate keratoconus is worse than that in normal eyes. The OQAS-II has the potential value in screening FFK from normal eyes and might be a useful tool for evaluating the progression of keratoconus.
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Impact of Corneoscleral Contact Lens Usage on Corneal Biomechanical Parameters in Keratoconic Eyes. Eye Contact Lens 2019; 45:318-323. [DOI: 10.1097/icl.0000000000000579] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Golan O, Piccinini AL, Hwang ES, De Oca Gonzalez IM, Krauthammer M, Khandelwal SS, Smadja D, Randleman JB. Distinguishing Highly Asymmetric Keratoconus Eyes Using Dual Scheimpflug/Placido Analysis. Am J Ophthalmol 2019; 201:46-53. [PMID: 30721688 DOI: 10.1016/j.ajo.2019.01.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 12/07/2018] [Accepted: 01/22/2019] [Indexed: 12/27/2022]
Abstract
PURPOSE To identify the best metrics or combination of metrics that provide the highest predictive power between normal eyes and the clinically unaffected eye of patients with highly asymmetric keratoconus using data from a Dual Scheimpflug/Placido device. DESIGN Retrospective case-control study. METHODS Combined Dual Scheimpflug/Placido imaging was obtained from the Galilei G4 device (Ziemer Ophthalmic Systems AG, Port, Switzerland) in 31 clinically unaffected eyes with highly asymmetric keratoconus and 178 eyes from 178 patients with bilaterally normal corneal examinations that underwent uneventful LASIK with at least 1 year follow-up. Receiver operating characteristic (ROC) curves were generated to determine area under the curve (AUC), sensitivity, and specificity for 87 metrics, and logistic regression modeling was used to determine optimal variable combinations. RESULTS No individual metric achieved an AUC greater than 0.79. A combined model consisting of 9 metrics yielded an AUC of 0.96, with 90.3% sensitivity and 92.6% specificity. Among those 9 metrics included, 5 related to corneal pachymetry: Opposite Sector Index and Anterior Height BFS Z from the anterior surface, Asphericity and Asymmetry Index, Posterior Height BFS Z, and Posterior Height BFS X from the posterior surface. The strongest variable in the model was the thinnest point location on the horizontal (x) axis. CONCLUSION While individual metrics performed poorly, using a combination of metrics from the combined Dual Scheimpflug/Placido device provided a useful model for differentiating normal corneas from the clinically normal eyes of patients with highly asymmetric keratoconus. Pachymetry values were the most impactful metrics.
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Affiliation(s)
- Oren Golan
- Keck School of Medicine of the University of Southern California, Los Angeles, California, USA; Tel Aviv Souraski Medical Center, Tel Aviv University, Tel Aviv, Israel
| | - Andre L Piccinini
- Keck School of Medicine of the University of Southern California, Los Angeles, California, USA; Sadalla Amin Ghanem Eye Hospital, Joinville, Santa Catarina, Brazil
| | - Eric S Hwang
- Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | | | - Mark Krauthammer
- Tel Aviv Souraski Medical Center, Tel Aviv University, Tel Aviv, Israel
| | | | - David Smadja
- Department of Ophthalmology, Shaare Zedek Medical Center, Jerusalem, Israel
| | - J Bradley Randleman
- Keck School of Medicine of the University of Southern California, Los Angeles, California, USA; USC Roski Eye Institute, Los Angeles, California, USA.
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Salomão M, Hoffling-Lima AL, Lopes B, Belin MW, Sena N, Dawson DG, Ambrósio R. Recent developments in keratoconus diagnosis. EXPERT REVIEW OF OPHTHALMOLOGY 2018. [DOI: 10.1080/17469899.2018.1555036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Marcella Salomão
- Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
- Instituto Benjamin Constant, Rio de Janeiro, Brazil
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
| | | | - Bernardo Lopes
- Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
- Instituto Benjamin Constant, Rio de Janeiro, Brazil
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
- Department of Biomaterial Mechanics, University of Liverpool, Liverpool, Tucson, UK
| | - Michael W. Belin
- Department of Ophthalmology and Visual Sciences, University of Arizona, USA
| | - Nelson Sena
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
- Department of Ophthalmology, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
| | - Daniel G. Dawson
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Renato Ambrósio
- Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
- Department of Ophthalmology, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
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Kataria P, Padmanabhan P, Gopalakrishnan A, Padmanaban V, Mahadik S, Ambrósio R. Accuracy of Scheimpflug-derived corneal biomechanical and tomographic indices for detecting subclinical and mild keratectasia in a South Asian population. J Cataract Refract Surg 2018; 45:328-336. [PMID: 30527442 DOI: 10.1016/j.jcrs.2018.10.030] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 09/27/2018] [Accepted: 10/03/2018] [Indexed: 10/27/2022]
Abstract
PURPOSE To test the predictive accuracy of the Belin-Ambrósio deviation index (BAD-D), the stiffness parameter A1 (SPA1), the Corvis biomechanical index (CBI), and the tomographic and biomechanical index (TBI) assessments for distinguishing subclinical and mild keratoconic eyes from normal eyes. SETTING Medical Research Foundation, Sankara Nethralaya, Chennai, India. DESIGN Retrospective case series. METHOD In this cross-sectional clinical study, the following 3 groups of eyes were analyzed: very asymmetric ectasia with normal topography (very asymmetric-normal topography), mild keratoconus, and normal control. All eyes had comprehensive assessment with corneal topography (TMS-IV), Scheimpflug tomography (Pentacam HR), and dynamic Scheimpflug biomechanical analysis (Corvis ST). The outcome measures were the BAD-D, SPA1, CBI, and TBI. Receiver operating characteristic (ROC) curve analysis was performed to determine each parameter's predictive accuracy in distinguishing between eyes with subclinical or mild keratoconus and control eyes. RESULTS The area under the curve (AUC) ROC values for the very asymmetric-normal topography and normal control comparison were 0.81 (BAD-D), 0.76 (SPA1), 0.78 (CBI), and 0.90 (TBI). The TBI (using cutoff value 0.16) showed the highest diagnostic accuracy (85%), with 84% sensitivity and 86% specificity. The AUC ROC values for the mild keratoconus and normal control comparison were 0.998 (BAD-D), 0.91 (SPA1), 0.97 (CBI), and 0.999 (TBI). The TBI (with a 0.63 cutoff) showed the highest accuracy (99.5%), with 99% sensitivity and 100% specificity. The TBI also showed the weakest correlation with mean keratometry, biomechanically corrected intraocular pressure, and central corneal thickness in normal eyes and keratoconic eyes. CONCLUSIONS The TBI best distinguished eyes with mild ectasia from normal eyes and had the weakest correlation with biomechanical confounding factors, reinforcing the hypothesis that the TBI represents corneal biomechanical susceptibility.
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Affiliation(s)
- Pratik Kataria
- Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Prema Padmanabhan
- Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India.
| | | | | | - Sanjay Mahadik
- Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Renato Ambrósio
- Federal University of the State of Rio de Janeiro, the Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil
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Visual quality with corneo-scleral contact lenses for keratoconus management. Cont Lens Anterior Eye 2018; 41:351-356. [DOI: 10.1016/j.clae.2018.01.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 01/10/2018] [Accepted: 01/12/2018] [Indexed: 11/22/2022]
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Salomão M, Lopes B, Ambrósio R, Faria-Correia F, Silva-Lopes Í, Azevedo-Wagner A, Tanos FW. Paradigms, Paradoxes, and Controversies on Keratoconus and Corneal Ectatic Diseases. ACTA ACUST UNITED AC 2018. [DOI: 10.5005/jp-journals-10025-1158] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Porcar E, Montalt JC, España-Gregori E, Peris-Martínez C. Corneo-scleral contact lenses in an uncommon case of keratoconus with high hyperopia and astigmatism. Cont Lens Anterior Eye 2017; 40:351-356. [PMID: 28712891 DOI: 10.1016/j.clae.2017.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 06/20/2017] [Accepted: 07/07/2017] [Indexed: 11/30/2022]
Abstract
PURPOSE To analyse the visual quality achieved by fitting corneo-scleral contact lenses (CScL) in an uncommon case of bilateral keratoconus, high hyperopia and astigmatism. METHODS A 45-year-old man presented for eye examination due to the unsatisfactory quality of his vision wearing soft toric contact lenses. He presented high hyperopia and astigmatism with bilateral keratoconus. He was fitted with CScL to correct his irregular astigmatism and ocular aberrations. A diagnostic trial set was used in the fitting process and he was assessed according to standardised fitting methodology. Visual acuity, corneal topography, biometry and ocular aberrations were evaluated. The follow-up period was 1year. RESULTS The best spectacle-corrected visual acuity was 20/32 with +8.00/-4.50×30° for the right eye (RE) and 20/25 with +7.75/-2.25×120° for the left eye (LE). After CScL fitting, visual acuity was improved to 20/20 and 20/16 for the RE and LE, respectively. The patient wore these contact lenses an average of 13h a day. The total high order aberrations decreased by approximately 79% in the RE (2.37-0.50μm) and 47% in the LE (1.04-0.55μm) after CScL fitting. Visual quality and wearing time were maintained after 1year wearing CScL. In addition, no adverse ocular effects were found during this period. CONCLUSION The present case report describes how the patient had CScL fitted successfully for management of keratoconus with high hyperopia and astigmatism. They provided optimal visual quality, along with prolonged use times and no adverse effects to the cornea.
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Affiliation(s)
- Esteban Porcar
- Department of Optics, Optometry and Vision Sciences, Physics College, University of Valencia, Burjassot, Valencia 46100, Spain.
| | - Juan Carlos Montalt
- Department of Optics, Optometry and Vision Sciences, Physics College, University of Valencia, Burjassot, Valencia 46100, Spain
| | - Enrique España-Gregori
- Department of Surgery, Ophthalmology Unit, la Fe University and Polytechnic Hospital, Faculty of Medicine and Odontology, University of Valencia, Hospital la Fe, Valencia 46026, Spain
| | - Cristina Peris-Martínez
- FISABIO Oftalmología Médica (FOM), Cornea Unit and Anterior Segment Diseases, Catholic University of Valencia, Valencia 46015, Spain
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Ocular, corneal, and internal aberrations in eyes with keratoconus, forme fruste keratoconus, and healthy eyes. Int Ophthalmol 2017. [DOI: 10.1007/s10792-017-0620-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Ortiz-Toquero S, Rodriguez G, de Juan V, Martin R. Repeatability of Wavefront Aberration Measurements With a Placido-Based Topographer in Normal and Keratoconic Eyes. J Refract Surg 2017; 32:338-44. [PMID: 27163620 DOI: 10.3928/1081597x-20160121-04] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 12/03/2015] [Indexed: 12/26/2022]
Abstract
PURPOSE To determine and compare the repeatability of anterior corneal higher order aberrations (HOAs) using a Placido-based topographer (Allegro Topolyzer; WaveLight Technologie AG, Alcon Laboratories, Erlangen, Germany) in a sample of normal and keratoconic eyes. METHODS Three repeated measurements of each cornea of normal and keratoconic eyes were taken with the Allegro Topolyzer. Repeatability of the HOAs (3rd- and 4th-order individual values and normalized polar Zernike coefficients, coma-like, root mean square (RMS) up to 8th-order values, HOA RMS, and total RMS for 6-mm pupil diameter) and central corneal power (3-mm pupil) were analyzed. Within-subject standard deviation (Sw), precision, repeatability, coefficient of variation (CV), and the intraclass correlation coefficient (ICC) were calculated. RESULTS Zernike coefficients were significantly different between the normal (36 eyes of 36 patients) and keratoconus (36 eyes of 36 patients) groups (P ≤ .03) except in Z(+1) 3, Z(+3) 3, Z(-4) 4, and Z(+4) 4. In the normal group, Sw was 0.031 µm or less, CV ranged from 6.49% (spherical aberration) to 37.18% (secondary astigmatism), and ICC values ranged from 0.227 to 0.982. In the keratoconus group, Sw was 0.059 µm or less, CV ranged from 2.06% (total RMS) to 25.82% (tetrafoil), and ICC values ranged from 0.839 to 0.996. In analyzing the keratoconus stages (Amsler-Krumeich classification), the repeatability of the Zernike coefficients tended to improve with increasing keratoconus stage. CONCLUSIONS The repeatability of corneal wavefront aberration provided by the Allegro Topolyzer was better in keratoconic eyes (good and moderate repeatability) than in normal eyes (moderate and poor repeatability). These results are important to eye care practitioners and refractive surgeons during refractive surgery planning or keratoconus detection, classification, and management. [J Refract Surg. 2016;32(5):338-344.].
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Affiliation(s)
- Davin Johnson
- Department of Ophthalmology, CHUM-Notre Dame Hospital, Montreal, Canada
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Estrella Velástegui PE, Vizcarra Proaño HF. Cuantificación de la severidad de las aberraciones de alto orden y de elevación de la cara posterior corneal mediante tomógrafo Scheimpflug/Plácido (Sirius®) en pacientes con diagnóstico de queratocono subclínico y manifiesto en la Clínica Oftálmica durante el segundo semestre del año 2013. REVISTA MEXICANA DE OFTALMOLOGÍA 2017. [DOI: 10.1016/j.mexoft.2015.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Hondur G, Cagil N, Sarac O, Ozcan ME, Kosekahya P. Pupillary Offset in Keratoconus and its Relationship with Clinical and Topographical Features. Curr Eye Res 2016; 42:708-712. [PMID: 27897442 DOI: 10.1080/02713683.2016.1242752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE To evaluate the change in the location of pupillary center with corneal tomography in keratoconic patients, and determine the correlation of pupillary offset with clinical and topographical features of keratoconus. METHODS Ninety-one eyes of the 54 patients with keratoconus in different stages and 39 eyes of 39 refractive surgery candidates with normal corneas were included in our study. Ocular aberrations and the pupillary offset parameters (x-offset and y-offset) over a 5 mm (undilated) pupil were measured with a Sirius corneal tomographer. A correlation analysis among the pupillary offset parameters and the possible determinative variables (topographical and tomographical parameters, corneal aberrations and best corrected visual acuity) was performed. RESULTS The mean pupillary offset was significantly greater in the keratoconic eyes compared with the controls (p = 0.003), and the difference was mostly due to the y-offset (p = 0.03). There was no significant difference between the groups in the mean horizontal pupillary offset value (p = 0.07). Both the vertical and the total pupillary offset values correlated significantly (p < 0.0001) with the keratoconus stage (r = 0.58 and r = 0.51, respectively). They also correlated with the corneal aberrations, and negatively correlated with the visual acuity. CONCLUSIONS The pupillary offset seems to correlate with the clinical and topographic features of keratoconus. It may be important to quantify its magnitude and direction in order to ensure correct centralization of the corneal procedures.
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Affiliation(s)
- Gozde Hondur
- a Department of Ophthalmology , Ulucanlar Eye Training and Research Hospital , Ankara , Turkey
| | - Nurullah Cagil
- b Department of Ophthalmology , Yildirim Beyazit University School of Medicine , Ankara , Turkey
| | - Ozge Sarac
- c Department of Ophthalmology , Ataturk Training and Research Hospital , Ankara , Turkey
| | - Meltem Ece Ozcan
- b Department of Ophthalmology , Yildirim Beyazit University School of Medicine , Ankara , Turkey
| | - Pinar Kosekahya
- a Department of Ophthalmology , Ulucanlar Eye Training and Research Hospital , Ankara , Turkey
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Subclinical keratoconus detection by pattern analysis of corneal and epithelial thickness maps with optical coherence tomography. J Cataract Refract Surg 2016; 42:284-95. [PMID: 27026454 DOI: 10.1016/j.jcrs.2015.09.021] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 08/22/2015] [Accepted: 09/01/2015] [Indexed: 11/24/2022]
Abstract
PURPOSE To screen for subclinical keratoconus by analyzing corneal, epithelial, and stromal thickness map patterns with Fourier-domain optical coherence tomography (OCT). SETTING Four centers in the United States. DESIGN Cross-sectional observational study. METHODS Eyes of normal subjects, subclinical keratoconus eyes, and the topographically normal eye of a unilateral keratoconus patient were studied. Corneas were scanned using a 26,000 Hz Fourier-domain OCT system (RTVue). Normal subjects were divided into training and evaluation groups. Corneal, epithelial, and stromal thickness maps and derived diagnostic indices, including pattern standard deviation (PSD) variables and pachymetric map-based keratoconus risk scores, were calculated from the OCT data. Area under the receiver operating characteristic curve (AUC) analysis was used to evaluate the diagnostic accuracy of the indices. RESULTS The study comprised 150 eyes of 83 normal subjects, 50 subclinical keratoconus eyes of 32 patients, and 1 topographically normal eye of a unilateral keratoconus patient. Subclinical keratoconus was characterized by inferotemporal thinning of the cornea, epithelium, and stroma. The PSD values for corneal (P < .001), epithelial (P < .001), and stromal (P = .049) thickness maps were all significantly higher in subclinical keratoconic eyes than in the normal group. The diagnostic accuracy was significantly higher for PSD variables (pachymetric PSD, AUC = 0.941; epithelial PSD, AUC = 0.985; stromal PSD, AUC = 0.924) than for the pachymetric map-based keratoconus risk score (AUC = 0.735). CONCLUSIONS High-resolution Fourier-domain OCT could map corneal, epithelial, and stromal thicknesses. Corneal and sublayer thickness changes in subclinical keratoconus could be detected with high accuracy using PSD variables. These new diagnostic variables might be useful in the detection of early keratoconus. FINANCIAL DISCLOSURES Oregon Health and Science University (OHSU) and Drs. Li, Tan, and Huang have a significant financial interest in Optovue, Inc. These potential conflicts have been reviewed and managed by OHSU. Dr. Brass receives research grants from Optovue, Inc. Drs. Chamberlain and Weiss have no financial or proprietary interest in any material or method mentioned.
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Colak HN, Kantarci FA, Yildirim A, Tatar MG, Goker H, Uslu H, Gurler B. Comparison of corneal topographic measurements and high order aberrations in keratoconus and normal eyes. Cont Lens Anterior Eye 2016; 39:380-4. [DOI: 10.1016/j.clae.2016.06.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Revised: 05/26/2016] [Accepted: 06/17/2016] [Indexed: 11/30/2022]
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Shokrollahzadeh F, Hashemi H, Jafarzadehpur E, Mirzajani A, Khabazkhoob M, Yekta A, Asgari S. Corneal aberration changes after rigid gas permeable contact lens wear in keratokonic patients. J Curr Ophthalmol 2016; 28:194-198. [PMID: 27830203 PMCID: PMC5093850 DOI: 10.1016/j.joco.2016.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 08/06/2016] [Indexed: 11/25/2022] Open
Abstract
Purpose To determine the short-term effect of rigid gas permeable (RGP) contact lenses on corneal aberrations in keratoconic patients. Method Sixteen keratoconic eyes with no history of RGP lens wear were included. They all had corneal aberrometry using Pentacam, and different aberration indices of the anterior and posterior surfaces of the cornea were measured before and 3 months after fitting RGP lenses. The effect of baseline parameters on these changes was tested in univariate and multiple models. Results Total aberrations and individual Zernike coefficients did not show statistically significant changes after using RGP lenses. Although not statistically significant, vertical coma decreased in the anterior (p = 0.073) and posterior surface (p = 0.095). Relationships that remained statistically significant in the multiple model were between baseline central corneal thickness and changes in total higher order aberrations and anterior 4th order astigmatism 0°, and between baseline 2nd order astigmatism 45° and its changes. Conclusion In this study, corneal aberrations remained unchanged 3 months after wearing RGP contact lens. Further studies with sufficient samples in different groups of keratoconus severity or baseline aberrations are needed to obtain more accurate results.
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Affiliation(s)
| | - Hassan Hashemi
- Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran
| | - Ebrahim Jafarzadehpur
- Department of Optometry, School of Rehabilitation Science, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Mirzajani
- Department of Optometry, School of Rehabilitation Science, Iran University of Medical Sciences, Tehran, Iran
| | - Mehdi Khabazkhoob
- Department of Medical Surgical Nursing, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abbasali Yekta
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Soheila Asgari
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, International Campus, Tehran, Iran
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Safarzadeh M, Nasiri N. Anterior segment characteristics in normal and keratoconus eyes evaluated with a combined Scheimpflug/Placido corneal imaging device. J Curr Ophthalmol 2016; 28:106-11. [PMID: 27579453 PMCID: PMC4992091 DOI: 10.1016/j.joco.2016.06.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/05/2016] [Accepted: 06/06/2016] [Indexed: 11/05/2022] Open
Abstract
Purpose To assess the anterior segment parameters of keratoconus (KC) eyes at different stages of the disease by a new Scheimpflug camera combined with Placido disk corneal topography (Sirius, CSO, Italy) in a sample of the Iranian population. Methods A total of 225 eyes of 225 individuals comprising 41 suspect KC, 40 mild KC, 71 moderate KC, 48 severe KC and 25 normal eyes were assessed for the following parameters: corneal thickness at the apex (CTA), thinnest corneal thickness (TCT), anterior chamber depth (ACD), corneal volume (CV), corneal keratometry (K), corneal asphericity (Q), and corneal elevation in the anterior and posterior surface. Also, the Zernike coefficients for the corneal aberrations including total root mean square (RMS), RMS Coma, RMS spherical aberration (SA), RMS Astigmatism, Baiocchi Calossi Versaci front index (BCVf), and BCV back index (BCVb) were noted for all eyes. Data was analyzed using analysis of variance (ANOVA) and post hoc Bonferroni test for comparison of the means of the five groups. P-value was considered significant if it was <0.05. Results The TCT, CTA and posterior corneal elevation were significantly different between all comparison groups (P < 0.05). ACD values showed inconsistent differences between groups. Mean value of CV in comparing normal eyes vs suspect KC group, normal eyes vs mild KC, and normal eyes vs moderate KC revealed statistically significant change (P < 0.05). Also, weak non-significant positive correlation was demonstrated between K and CV (r = 0.08). There were statistically significant differences in total RMS, RMS coma, BCVf, and BCVb for most groups (P < 0.05). Conclusion Posterior corneal elevation, corneal thickness and high order aberrations are important indices that need to be considered to diagnose different grades of keratoconus.
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Affiliation(s)
- Masoud Safarzadeh
- Department of Optometry, Tehran University of Medical Sciences, Tehran, Iran
| | - Nader Nasiri
- Department of Ophthalmology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Assessment of Corneal Epithelial Thickness in Asymmetric Keratoconic Eyes and Normal Eyes Using Fourier Domain Optical Coherence Tomography. J Ophthalmol 2016; 2016:5697343. [PMID: 27379181 PMCID: PMC4917694 DOI: 10.1155/2016/5697343] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/10/2016] [Indexed: 11/18/2022] Open
Abstract
Purpose. To compare the characteristics of asymmetric keratoconic eyes and normal eyes by Fourier domain optical coherence tomography (OCT) corneal mapping. Methods. Retrospective corneal and epithelial thickness OCT data for 74 patients were compared in three groups of eyes: keratoconic (n = 22) and normal fellow eyes (n = 22) in patients with asymmetric keratoconus and normal eyes (n = 104) in healthy subjects. Areas under the curve (AUC) of receiver operator characteristic (ROC) curves for each variable were compared across groups to indicate their discrimination capacity. Results. Three variables were found to differ significantly between fellow eyes and normal eyes (all p < 0.05): minimum corneal thickness, thinnest corneal point, and central corneal thickness. These variables combined showed a high discrimination power to differentiate fellow eyes from normal eyes indicated by an AUC of 0.840 (95% CI: 0.762-0.918). Conclusions. Our findings indicate that topographically normal fellow eyes in patients with very asymmetric keratoconus differ from the eyes of healthy individuals in terms of their corneal epithelial and pachymetry maps. This type of information could be useful for an early diagnosis of keratoconus in topographically normal eyes.
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Evaluation of corneal higher order aberrations in normal topographic patterns. J Curr Ophthalmol 2016; 28:75-80. [PMID: 27331151 PMCID: PMC4909702 DOI: 10.1016/j.joco.2016.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 03/10/2016] [Accepted: 03/11/2016] [Indexed: 11/25/2022] Open
Abstract
Purpose This study reports the characteristics of corneal higher order aberrations (HOAs) in eyes with normal topographic pattern using the Pentacam scheimpflug system. Methods In this prospective, observational, comparative study, 165 eyes of 97 patients separated into five groups based on corneal topographic patterns were enrolled. All eyes received a comprehensive ophthalmologic examination including corneal tomographic analysis with the Pentacam system. Keratometry, corneal cylinder, and corneal aberrometric data were recorded and analyzed. Root mean square values (RMS) were calculated for corneal HOAs up to the 6th order, total coma, total trefoil, total spherical aberration, total tetrafoil, and higher order astigmatism. Evaluation of these data to discriminate between the five groups was assessed using the analysis of variance test by Generalized Estimation Equation Linear Model. Results Corneal HOAs were found to be significantly higher for Asymmetric Bow Tie and Irregular groups than other groups (p = <0.001). RMS of total coma aberration (Z3−1, Z31, Z5−1, Z51) were significantly greater in the Asymmetric Bow Tie pattern than others, and RMS of total Spherical aberration (Z40, Z60) was significantly higher in the Irregular pattern than other groups (p = <0.001). The results of our study demonstrate that a tendency toward significant higher values of trefoil, tetrafoil, and higher order astigmatism in Irregular pattern (all p < 0.05). Significantly higher amounts of 3rd order RMS in Asymmetric Bow Tie group and 4th to 6th order RMS in Irregular pattern group were other outcomes of our study (p = <0.001). Conclusions Based on results in this study, there were a good correlation between corneal topographic pattern and corneal HOAs in normal eyes. These results indicate that the corneal HOAs values are largely determined by the topographic patterns. A larger sample size would perhaps have been beneficial to yield in more accurate outcomes.
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Luz A, Lopes B, Hallahan KM, Valbon B, Fontes B, Schor P, Dupps WJ, Ambrósio R. Discriminant Value of Custom Ocular Response Analyzer Waveform Derivatives in Forme Fruste Keratoconus. Am J Ophthalmol 2016; 164:14-21. [PMID: 26743618 DOI: 10.1016/j.ajo.2015.12.020] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 12/18/2015] [Accepted: 12/18/2015] [Indexed: 11/28/2022]
Abstract
PURPOSE To evaluate the performance of corneal hysteresis (CH), corneal resistance factor (CRF), 37 Ocular Response Analyzer (ORA) waveform parameters, and 15 investigator-derived ORA variables in differentiating forme fruste keratoconus (KC) from normal corneas. DESIGN Case-control study. METHODS Seventy-eight eyes of 78 unaffected patients and 21 topographically normal eyes of 21 forme fruste KC patients with topographically manifest KC in the contralateral eye were matched for age, the thinnest point of the cornea, central corneal thickness, and maximum keratometry. Fifteen candidate variables were derived from exported ORA signals to characterize putative indicators of biomechanical behavior, and 37 waveform parameters were tested. Differences between groups were assessed by the Mann-Whitney test. The area under the receiver operating characteristic curve (AUROC) was used to compare the diagnostic performance. RESULTS Ten of 54 parameters reached significant differences between the groups (Mann-Whitney test, P < .05). Neither CRF nor CH differed significantly between the groups. Among the ORA waveform measurements, the best parameters were those related to the area under the first peak, p1area, and p1area1 (AUROC, 0.714 ± 0.064 and 0.721 ± 0.065, respectively). Among the investigator ORA variables, a measure incorporating the pressure-deformation relationship of the entire response cycle performed best (hysteresis loop area, AUROC, 0.694 ± 0.067). CONCLUSION Waveform-derived ORA parameters, including a custom measure incorporating the pressure-deformation relationship of the entire response cycle, performed better than traditional CH and CRF parameters in differentiating forme fruste KC from normal corneas.
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Affiliation(s)
- Allan Luz
- Department for Ophthalmology of the Federal University of Sao Paulo, Sao Paulo, Brazil; Hospital de Olhos de Sergipe, Aracaju, Brazil; Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil.
| | - Bernardo Lopes
- Department for Ophthalmology of the Federal University of Sao Paulo, Sao Paulo, Brazil; Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil; Instituto de Olhos Renato Ambrósio and Visare Personal Laser, Rio de Janeiro, Brazil
| | - Katie M Hallahan
- Cole Eye Institute, Cleveland Clinic; and Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio
| | - Bruno Valbon
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil; Instituto de Olhos Renato Ambrósio and Visare Personal Laser, Rio de Janeiro, Brazil
| | - Bruno Fontes
- Instituto de Olhos Renato Ambrósio and Visare Personal Laser, Rio de Janeiro, Brazil
| | - Paulo Schor
- Department for Ophthalmology of the Federal University of Sao Paulo, Sao Paulo, Brazil
| | - William J Dupps
- Cole Eye Institute, Cleveland Clinic; and Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio
| | - Renato Ambrósio
- Department for Ophthalmology of the Federal University of Sao Paulo, Sao Paulo, Brazil; Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil; Instituto de Olhos Renato Ambrósio and Visare Personal Laser, Rio de Janeiro, Brazil
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Tummanapalli SS, Potluri H, Vaddavalli PK, Sangwan VS. Efficacy of axial and tangential corneal topography maps in detecting subclinical keratoconus. J Cataract Refract Surg 2015; 41:2205-14. [DOI: 10.1016/j.jcrs.2015.10.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 04/09/2015] [Accepted: 04/18/2015] [Indexed: 10/22/2022]
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Abstract
Purpose To determine normative reference ranges for higher-order wavefront error (HO-WFE), compare these values with those in common ocular pathologies, and evaluate treatments. Methods A review of 17 major studies on HO-WFE was made, involving data for a total of 31,605 subjects. The upper limit of the 95% confidence interval (CI) for HO-WFE was calculated from the most comprehensive of these studies using normal healthy patients aged 20 to 80 years. There were no studies identified using the natural pupil size for subjects, and for this reason, the HO-WFE was tabulated for pupil diameters of 3 to 7 mm. Effects of keratoconus, pterygium, cataract, and dry eye on HO-WFE were reviewed and treatment efficacy was considered. Results The calculated upper limit of the 95% CI for HO-WFE in a healthy normal 35-year-old patient with a mesopic pupil diameter of 6 mm would be 0.471 μm (471 nm) root-mean-square or less. Although the normal HO-WFE increases with age for a given pupil size, it is not yet completely clear how the concurrent influence of age-related pupillary miosis affects these findings. Abnormal ocular conditions such as keratoconus can induce a large HO-WFE, often in excess of 3.0 μm, particularly attributed to coma. For pterygium or cortical cataract, a combination of coma and trefoil was more commonly induced. Nuclear cataract can induce a negative spherical HO-WFE, usually in excess of 1.0 μm. Conclusions The upper limit of the 95% CI for HO-WFE root-mean-square is about 0.5 μm with normal physiological pupil sizes. With ocular pathologies, HO-WFE can be in excess of 1.0 μm, although many devices and therapeutic and surgical treatments are reported to be highly effective at minimizing HO-WFE. More accurate normative reference ranges for HO-WFE will require future studies using the subjects’ natural pupil size.
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Affiliation(s)
- Adrian S Bruce
- *BScOptom, PhD, FAAO †OD, DSc (Hon), FAAO Australian College of Optometry, Carlton, Victoria, Australia (ASB); Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Australia (ASB); and Nicolitz Eye Consultants, Jacksonville, Florida (LJC)
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Corneal epithelial thickness mapping using Fourier-domain optical coherence tomography for detection of form fruste keratoconus. J Cataract Refract Surg 2015; 41:812-20. [DOI: 10.1016/j.jcrs.2014.06.043] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 06/13/2014] [Accepted: 06/17/2014] [Indexed: 11/17/2022]
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