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Paul PK, Hossan A, Ullah SMA. KeratoEL: Detection of keratoconus using corneal parameters with ensemble learning. Health Sci Rep 2024; 7:e2202. [PMID: 38952404 PMCID: PMC11214914 DOI: 10.1002/hsr2.2202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 04/01/2024] [Accepted: 05/16/2024] [Indexed: 07/03/2024] Open
Abstract
Background and Aims Keratoconus is a progressive eye condition in which the normally round cornea thins and bulges outwards into a cone shape. This irregular shape causes light to scatter in multiple directions as it enters the eye, leading to distorted vision, increased sensitivity to light and frequent changes in the prescription of glasses or contact lenses. Detecting keratoconus at an early stage is not only difficult but also challenging. Methods The study has proposed an ensemble-based machine learning (ML) technique named KeratoEL to detect keratoconus at an early stage. The proposed KeratoEL model combines the basic machine learning algorithms, namely support vector machine (SVM), decision tree (DT), random forest (RF) and artificial neural network (ANN). Before employing the ML model for keratoconus detection, the data set is first preprocessed manually by eliminating some features that don't contribute any significant value to predict the exact class. Moreover, the output features are labelled into three different classes and Extra Trees Classifier is used to find out the important features. Then, the features are sorted in descending order and top 45, 30, and 15 features are taken as input datasets against the output. Finally, different machine learning models are tested using the input datasets and performance metrics are measured. Results The proposed model obtains 98.0%, 98.9% and 99.8% accuracy for top 45, 30, and 15 number of features respectively. Overall experimental results show that the proposed ensemble model outperforms the existing machine learning models. Conclusion The proposed KeratoEL model effectively detects keratoconus at an early stage by combining SVM, DT, RF, and ANN algorithms, demonstrating superior performance over existing models. These results underscore the potential of the KeratoEL ensemble approach in enhancing early detection and treatment of keratoconus.
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Affiliation(s)
- Prodeep Kumar Paul
- Department of Electronics and Communication EngineeringKhulna University of Engineering & Technology (KUET)KhulnaBangladesh
| | - Arif Hossan
- Department of Electronics and Communication EngineeringKhulna University of Engineering & Technology (KUET)KhulnaBangladesh
| | - Shah Muhammad A. Ullah
- Department of Electronics and Communication EngineeringKhulna University of Engineering & Technology (KUET)KhulnaBangladesh
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Dutta R, Iyer G, Srinivasan B, Iqbal A. Aberration change after scleral lens wear in eyes with pellucid marginal degenerations. Indian J Ophthalmol 2024; 72:1037-1042. [PMID: 38324626 PMCID: PMC11329822 DOI: 10.4103/ijo.ijo_1820_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 11/28/2023] [Accepted: 12/26/2023] [Indexed: 02/09/2024] Open
Abstract
PURPOSE To investigate the impact of scleral lenses (SLs) on higher-order aberrations (HOAs), corrected distance visual acuity (CDVA), and contrast sensitivity (CS) in pellucid marginal degeneration (PMD) eyes. METHODS SLs were fitted in 24 eyes diagnosed with PMD. CDVA, CS, and HOAs were measured at baseline and with the lens on the eye. The HOAs were measured using an i-Trace aberrometer. RESULTS A statistically significant improvement was noted in CDVA ( P < 0.001) with BSS lenses (0.05 ± 0.04) compared to baseline (0.42 ± 0.06). Front surface eccentricity 1 (FSE1) lens provided the best CDVA in most of the eyes. The baseline CS of 1.24 ± 0.74 improved to 1.58 ± 0.48 with SL and reported a statistically significant improvement ( P < 0.001) and a gain of 6 letters. The baseline higher order-root mean square (HO-RMS) was 0.89 ± 0.53 µm, which reduced to 0.38 ± 0.24 µm ( P < 0.001), and RMS coma of 0.45 ± 0.29 µm improved to 0.20 ± 0.12 µm ( P < 0.001). Though there was a marginal reduction from 0.04 ± 0.14 to 0.03 ± 0.07, RMS spherical aberration did not show any statistically significant difference ( P = 0.37). RMS secondary astigmatism reduced from 0.17 ± 0.15 µm to 0.08 ± 0.12 µm ( P = 0.007), and RMS trefoil reduced to 0.13 ± 0.09 µm from 0.64 ± 0.36 µm ( P < 0.001) with SLs and showed statistically significant improvement. CONCLUSION SLs can be considered an effective option that corrects a significant amount of HOAs and enhances visual performances in PMD eyes.
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Affiliation(s)
- Ronit Dutta
- Department of Contact Lens, Sankara Nethralaya, Unit of Medical Research Foundation, Chennai, Tamil Nadu, India
| | - Geetha Iyer
- CJ Shah Cornea Services, Sankara Nethralaya, Unit of Medical Research Foundation, Chennai, Tamil Nadu, India
| | - Bhaskar Srinivasan
- CJ Shah Cornea Services, Sankara Nethralaya, Unit of Medical Research Foundation, Chennai, Tamil Nadu, India
| | - Asif Iqbal
- Department of Contact Lens, Sankara Nethralaya, Unit of Medical Research Foundation, Chennai, Tamil Nadu, India
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Dutta R, Iyer G, Srinivasan B, Iqbal A. Scleral lens induced short term corneal changes in eyes with Pellucid Marginal Degeneration. Cont Lens Anterior Eye 2024; 47:102173. [PMID: 38653594 DOI: 10.1016/j.clae.2024.102173] [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: 04/06/2023] [Revised: 04/17/2024] [Accepted: 04/20/2024] [Indexed: 04/25/2024]
Abstract
PURPOSE To investigate the short-term effect of scleral lens (SL) on corneal curvature and corneal oedema in Pellucid Marginal Degeneration (PMD) eyes. METHODS Corneal anterior, posterior curvature and corneal thickness were measured in 14 eyes of 14 PMD participants with Schiempflug imaging at different corneal diameters and meridians at baseline and after 6 h of SL wear. RESULTS There was a significant flattening (up to 0.26 mm) of the anterior corneal curvature noted in the inferotemporal quadrant (from 210 to 255 degree at 2 mm, 8 mm and 10 mm corneal diameter), inferonasal quadrant (from 285 to 345 degree at 6 mm and 8 mm corneal diameter), and inferiorly at 2 mm and 10 mm corneal diameter (p < 0.05). Similarly, posterior corneal curvature showed statistically significant steepening mostly in inferotemporal quadrants (from 195 to 255 degree from 4 mm to 8 mm corneal diameter) and inferonasally at 2 mm and 4 mm corneal diameter (p < 0.05). A statistically significant increase in the corneal thickness noted in different corneal diameters with corneal oedema ranging from 2.10 % to 4.00 % after 6 h of SL wear. A gradual increase in corneal oedema was noted form centre to periphery. The baseline central fluid reservoir thickness (FRT) was 341.07 ± 139.8 which reduced to 276.71 ± 114.32 µm after 6 h of lens wear. No significant correlation was noted between corneal oedema with different parameters like initial and final FRT, change in anterior and posterior corneal curvature, and lens thickness (p > 0.05). CONCLUSIONS Short-term SL wear induced a clinically acceptable range of corneal oedema. A clinically significant flattening in anterior curvature and minimal steepening in posterior curvature were noted. Practitioners should be careful while measuring corneal parameters in PMD eyes wearing SL, as these alterations can provide false impression of disease progression.
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Affiliation(s)
- Ronit Dutta
- Department of Contact Lens, Sankara Nethralaya, Unit of Medical Research Foundation, Chennai, India
| | - Geetha Iyer
- CJ Shah Cornea Services, Sankara Nethralaya, Unit of Medical Research Foundation, Chennai, India
| | - Bhaskar Srinivasan
- CJ Shah Cornea Services, Sankara Nethralaya, Unit of Medical Research Foundation, Chennai, India
| | - Asif Iqbal
- Department of Contact Lens, Sankara Nethralaya, Unit of Medical Research Foundation, Chennai, India.
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Mergen B, Sideroudi H, Seitz B, Flockerzi E. Altered Corneal Biomechanics According to the Biomechanical E-Staging in Pellucid Marginal Degeneration. Cornea 2024:00003226-990000000-00478. [PMID: 38334467 DOI: 10.1097/ico.0000000000003479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 12/03/2023] [Indexed: 02/10/2024]
Abstract
PURPOSE The purpose of this study was to investigate corneal biomechanics in pellucid marginal degeneration (PMD) compared with healthy controls using Corvis ST (Oculus, Germany) by using the new biomechanical E-staging (based on the Corvis Biomechanical Factor, the linearized Corvis Biomechanical Index) together with tomographic parameters. METHODS Corneal biomechanical and topographic data of 75 eyes of 75 patients with PMD and 75 eyes of 75 age-matched and sex-matched healthy controls were investigated. Topographic parameters (K1, K2, Kmax, central corneal thickness (CCT), and Belin/Ambrósio Deviation Index (BAD-D) were evaluated in dependence of and correlated with the biomechanically defined E-stages. Biomechanical parameters were also recorded for the 2 groups. RESULTS Patients with PMD showed higher K2, Kmax, BAD-D, and Corvis Biomechanical Factor values and a lower CCT compared with healthy controls (P < 0.001). The E-stage was positively correlated with K1, K2, Kmax, BAD-D, and intraocular pressure difference and negatively correlated with CCT. Stage-dependent analysis revealed a significant increase in K1, K2, Kmax (P < 0.001), and BAD-D (P = 0.041) in stage E3 compared with E0 and a significant decrease in stage E2 in CCT (P = 0.009) compared with E0. CONCLUSIONS This study showed that patients with PMD may have a reduced corneal stiffness compared with healthy controls which worsens with increasing E-stage. Significant changes in topographic parameters were observed at stage E2 for CCT and at stage E3 for K1, K2, Kmax, and BAD-D when compared with stage E0.
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Affiliation(s)
- Burak Mergen
- Department of Ophthalmology, Saarland University Medical Center (UKS), Homburg/Saar, Germany; and
- Department of Ophthalmology, University of Health Sciences, Basaksehir Cam and Sakura City Hospital, Istanbul, Turkey
| | - Haris Sideroudi
- Department of Ophthalmology, Saarland University Medical Center (UKS), Homburg/Saar, Germany; and
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center (UKS), Homburg/Saar, Germany; and
| | - Elias Flockerzi
- Department of Ophthalmology, Saarland University Medical Center (UKS), Homburg/Saar, Germany; and
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Sahebjada S, Chan E, Sutton G, Pang CPC, Kerdraon Y, Natarajan S, Meteoukki W, Ang A, Daniell M, Baird PN. Keratoconus International Consortium (KIC)- advancing keratoconus research. BMC Ophthalmol 2023; 23:337. [PMID: 37501133 PMCID: PMC10375634 DOI: 10.1186/s12886-023-03087-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 07/16/2023] [Indexed: 07/29/2023] Open
Abstract
CLINICAL RELEVANCE The Keratoconus International Consortium (KIC) will allow better understanding of keratoconus. BACKGROUND Keratoconus is a disorder characterised by corneal elevation and thinning, leading to reduced vision. The current gaps in understanding of this disease will be discussed and the need for a multi-pronged and multi-centre engagement to enhance our understanding of keratoconus will be highlighted. DESIGN KIC has been established to address the gaps in our understanding of keratoconus with the aim of collecting baseline as well as longitudinal data on several fields. PARTICIPANTS Keratoconus and control (no corneal condition) subjects from different sites globally will be recruited in the study. METHODS KIC collects data using an online, secure database, which enables standardised data collection at member sites. Data fields collected include medical history, clinical features, quality of life and economic burden questionnaires and possible genetic sample collection from patients of different ethnicities across different geographical locations. RESULTS There are currently 40 Australian and international clinics or hospital departments who have joined the KIC. Baseline data has so far been collected on 1130 keratoconus patients and indicates a median age of 29.70 years with 61% being male. A total of 15.3% report a positive family history of keratoconus and 57.7% self-report a history of frequent eye rubbing. CONCLUSION The strength of this consortium is its international, collaborative design and use of a common data collection tool. Inclusion and analyses of cross-sectional and longitudinal data will help answer many questions that remain in keratoconus, including factors affecting progression and treatment outcomes.
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Affiliation(s)
- Srujana Sahebjada
- Centre for Eye Research Australia, Level 7, 32 Gisborne St, East Melbourne, Victoria, 3002, Australia.
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, Australia.
| | - Elsie Chan
- Centre for Eye Research Australia, Level 7, 32 Gisborne St, East Melbourne, Victoria, 3002, Australia
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, Australia
- Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Gerard Sutton
- Sydney Medical School, The University of Sydney, Sydney, Australia
- NSW Tissue Banks, Sydney, Australia
| | | | - Yves Kerdraon
- Sydney Medical School, The University of Sydney, Sydney, Australia
- Envision Eye Centre, Sydney, Australia
| | | | - Wafaa Meteoukki
- Molecular and Cellular Genetics Laboratory, Oran University of Science and Technology - Mohamed Boudiaf (USTOMB), Oran, Algeria
| | | | - Mark Daniell
- Centre for Eye Research Australia, Level 7, 32 Gisborne St, East Melbourne, Victoria, 3002, Australia
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, Australia
- Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Paul N Baird
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, Australia
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Regueiro U, López-López M, Varela-Fernández R, Otero-Espinar FJ, Lema I. Biomedical Applications of Lactoferrin on the Ocular Surface. Pharmaceutics 2023; 15:pharmaceutics15030865. [PMID: 36986726 PMCID: PMC10052036 DOI: 10.3390/pharmaceutics15030865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/03/2023] [Accepted: 03/05/2023] [Indexed: 03/11/2023] Open
Abstract
Lactoferrin (LF) is a first-line defense protein with a pleiotropic functional pattern that includes anti-inflammatory, immunomodulatory, antiviral, antibacterial, and antitumoral properties. Remarkably, this iron-binding glycoprotein promotes iron retention, restricting free radical production and avoiding oxidative damage and inflammation. On the ocular surface, LF is released from corneal epithelial cells and lacrimal glands, representing a significant percentage of the total tear fluid proteins. Due to its multifunctionality, the availability of LF may be limited in several ocular disorders. Consequently, to reinforce the action of this highly beneficial glycoprotein on the ocular surface, LF has been proposed for the treatment of different conditions such as dry eye, keratoconus, conjunctivitis, and viral or bacterial ocular infections, among others. In this review, we outline the structure and the biological functions of LF, its relevant role at the ocular surface, its implication in LF-related ocular surface disorders, and its potential for biomedical applications.
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Affiliation(s)
- Uxía Regueiro
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
- Department of Surgery and Medical-Surgical Specialties, Faculty of Optics and Optometry, University of Santiago de Compostela (USC), 15705 Santiago de Compostela, Spain
| | - Maite López-López
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
- Department of Surgery and Medical-Surgical Specialties, Faculty of Optics and Optometry, University of Santiago de Compostela (USC), 15705 Santiago de Compostela, Spain
| | - Rubén Varela-Fernández
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, University of Santiago de Compostela (USC), 15705 Santiago de Compostela, Spain
| | - Francisco Javier Otero-Espinar
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, University of Santiago de Compostela (USC), 15705 Santiago de Compostela, Spain
- Institute of Materials (iMATUS), University of Santiago de Compostela (USC), 15705 Santiago de Compostela, Spain
- Correspondence: (F.J.O.-E.); (I.L.)
| | - Isabel Lema
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
- Department of Surgery and Medical-Surgical Specialties, Faculty of Optics and Optometry, University of Santiago de Compostela (USC), 15705 Santiago de Compostela, Spain
- Galician Institute of Ophthalmology (INGO), Conxo Provincial Hospital, 15706 Santiago de Compostela, Spain
- Correspondence: (F.J.O.-E.); (I.L.)
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Sideroudi H, Flockerzi E, Seitz B. Differential Diagnosis of Keratoconus Based on New Technologies. Klin Monbl Augenheilkd 2023; 240:57-72. [PMID: 35940178 DOI: 10.1055/a-1920-6929] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Keratoconus (KC) must be distinguished from other corneal ectatic diseases and thinning disorders for stage-appropriate and suitable management of each condition. The most relevant corneal pathologies that may imitate the tomographic KC pattern are pellucid marginal degeneration (PMD), keratoglobus, posterior keratoconus, and Fuchs-Terrien marginal degeneration (FTMD). In moderate cases of KC, differentiation is typically possible using slit lamp examination and corneal tomography with evaluation of the location of the corneal thinning region. In early cases, however, differential diagnosis may be more challenging since the cornea may look relatively normal. In severe cases, the extended area of corneal thinning also complicates differentiation. Biomicroscopic findings cannot always give all the information needed to distinguish KC from related ectatic corneal conditions. The aim of this work is to discuss contemporary techniques and findings to assist physicians to identify the correct diagnosis. Corneal topography has been used in recent decades as the main tool for imaging in ectatic corneal diseases. Moreover, Scheimpflug cameras (corneal tomographers), which analyze both anterior and posterior corneal surfaces, curvatures, pachymetry, elevation data, higher order aberrations, Fourier analysis of keratometric data, and corneal density have become the most promising tools for diagnosis and follow-up of ectatic diseases. A noninvasive air pulse tonometer in conjunction with an ultrahigh-speed Scheimpflug camera complements tomographic findings by analyzing biomechanical corneal properties. Α confocal microscopy system, which is a novel clinical technique for the study of corneal cellular structure, could contribute effectively in the same direction. Moreover, anterior segment optical coherence tomography (AS-OCT) creates cross-sections, which can be generated into a three-dimensional structure to produce corneal epithelial thickness (ET) measurements. ET mapping is increasingly recognized as a sensitive tool for the diagnosis of ocular surface disorders. Combining information of all these systems could lead to a more effective identification and differential diagnosis of ectatic corneal disorders.
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Affiliation(s)
- Haris Sideroudi
- Department of Ophthalmology, Saarland University Medical Center and Saarland University Faculty of Medicine, Homburg/Saar, Germany
| | - Elias Flockerzi
- Department of Ophthalmology, Saarland University Medical Center and Saarland University Faculty of Medicine, Homburg/Saar, Germany
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center and Saarland University Faculty of Medicine, Homburg/Saar, Germany
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Regueiro U, López-López M, Varela-Fernández R, Sobrino T, Diez-Feijoo E, Lema I. Immunomodulatory Effect of Human Lactoferrin on Toll-like Receptors 2 Expression as Therapeutic Approach for Keratoconus. Int J Mol Sci 2022; 23:ijms232012350. [PMID: 36293206 PMCID: PMC9604127 DOI: 10.3390/ijms232012350] [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: 09/06/2022] [Revised: 10/07/2022] [Accepted: 10/08/2022] [Indexed: 11/07/2022] Open
Abstract
Keratoconus (KC) is a corneal disorder whose etiology shares a close relationship with Lactoferrin (LTF) dysregulation and Toll-like Receptors 2 (TLR2) overexpression. This study shows how these two important biomarkers are clinically and molecularly interrelated, increasing knowledge about KC pathophysiology, and opening the door to future therapies. In this prospective clinical study, serum and tear LTF concentrations were quantified in 90 KC patients and 60 controls. A correlation analysis with multiple blood and tear immunoinflammatory mediators, and KC-associated tomographic parameters, was performed. An in vitro study using HEK-BlueTMhTLR2 cell cultures was also conducted to determine the expression and functionality of TLR2 under the influence of LTF treatment. As a result, a LTF decreased was observed in KC patients compared to controls (p < 0.0001), evidencing the strong correlation with TLR2 overexpression at systemic and ocular surface level, with inflammatory mediator upregulation and with KC severity. In stimulated cell cultures, TLR2 expression was decreased using 2 mg/mL of LTF. The levels of secreted embryonic alkaline phosphatase (SEAP) and interleukin-8 (IL-8) were also reduced in supernatants after LTF treatment. As conclusions, the dysregulation of LTF and TLR2 in the ocular surface of KC patients contributes to KC severity by maintaining a detrimental chronic immune−inflammatory state. The immunomodulatory properties of LTF on TLR2 expression suggest its potential as a therapeutic approach for KC.
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Affiliation(s)
- Uxía Regueiro
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
- Department of Surgery and Medical-Surgical Specialties, Faculty of Optics and Optometry, University of Santiago de Compostela (USC), 15705 Santiago de Compostela, Spain
- Correspondence: (U.R.); (I.L.); Tel.: +34-981951086 (U.R. & I.L.)
| | - Maite López-López
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
- Department of Surgery and Medical-Surgical Specialties, Faculty of Optics and Optometry, University of Santiago de Compostela (USC), 15705 Santiago de Compostela, Spain
| | - Rubén Varela-Fernández
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, University of Santiago de Compostela (USC), 15705 Santiago de Compostela, Spain
| | - Tomás Sobrino
- NeuroAging Laboratory (NEURAL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
| | - Elio Diez-Feijoo
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
- Department of Surgery and Medical-Surgical Specialties, Faculty of Optics and Optometry, University of Santiago de Compostela (USC), 15705 Santiago de Compostela, Spain
- Galician Institute of Ophthalmology (INGO), Conxo Provincial Hospital, 15706 Santiago de Compostela, Spain
| | - Isabel Lema
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
- Department of Surgery and Medical-Surgical Specialties, Faculty of Optics and Optometry, University of Santiago de Compostela (USC), 15705 Santiago de Compostela, Spain
- Galician Institute of Ophthalmology (INGO), Conxo Provincial Hospital, 15706 Santiago de Compostela, Spain
- Correspondence: (U.R.); (I.L.); Tel.: +34-981951086 (U.R. & I.L.)
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Demographic, clinical and tomographic characteristics of pellucid marginal degeneration patients in South Egyptian population. Int Ophthalmol 2022; 42:3237-3242. [PMID: 36001208 PMCID: PMC9509300 DOI: 10.1007/s10792-022-02326-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 04/18/2022] [Indexed: 12/04/2022]
Abstract
Purpose To retrospectively evaluate the demographic, clinical, and tomographic characteristics of pellucid marginal degeneration (PMD) patients in South Egypt. Methods This study was retrospective cross-sectional, including all patients who attended and sought refractive surgery at Sohag Center for Corneal and Refractive Surgeries, Sohag, South Egypt, between October 2016 and October 2020, and had a diagnosis of PMD. It included cases of PMD at different stages. Cases with PMD were diagnosed by the two authors (experienced in corneal refractive surgery), combining both slit-lamp biomicroscopy findings and corneal tomography. Results Out of the 2534 patients attending the Sohag Center for Corneal and Refractive Surgeries (between October 2016 and May 2020) seeking correction of their refractive errors, 24 patients were found to fit in the diagnosis of PMD. Forty-three eyes of the 24 patients were diagnosed with PMD. The topographic patterns ranged from horizontal bow tie (against the rule astigmatism) being the least presenting, followed by crab claw, then butterfly pattern. Conclusion PMD is a separate entity of the ectatic corneal spectrum that can easily be misinterpreted as Keratoconus. Topographic and tomographic patterns cannot solely diagnose PMD as they should be enforced by slit-lamp findings.
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López-López M, Regueiro U, Bravo SB, Chantada-Vázquez MDP, Pena C, Díez-Feijoo E, Hervella P, Lema I. Shotgun Proteomics for the Identification and Profiling of the Tear Proteome of Keratoconus Patients. Invest Ophthalmol Vis Sci 2022; 63:12. [PMID: 35551575 PMCID: PMC9123485 DOI: 10.1167/iovs.63.5.12] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The qualitative approach followed in this study aims to obtain an extensive view of the keratoconus (KC) tear proteome, which could highlight proteins previously undetected and enlarge our knowledge of the disease's pathophysiology. Methods Twenty-five patients diagnosed with KC and 25 control subjects were studied in a prospective, cross-sectional study. KC screening examinations, including clinical and tomographic examinations, were performed on all participants. Tear samples were collected using Schirmer strips and analyzed by liquid chromatography-tandem mass spectrometry in a data-dependent workflow. A spectral count was used as a semiquantification tool. The tear proteomes of both groups were identified and profiled, and the functional interactions and biological characterization of differential proteins were analyzed using in silico tools. Results We identified a total of 232 proteins, of whom 133 were expressed in both groups’ samples; 41 were observed only in control samples and 58 were identified just in tears of patients with KC. A semiquantitative analysis showed the dysregulation of 17 proteins in the KC samples. An in silico analysis linked proteins only expressed in KC samples to oxidative stress, skin development, and apoptosis. The dysregulation of proteins involved in iron transport, inflammation, oxidative stress, and protease inhibition was observed in the semiquantitative results. Conclusions A shotgun analysis showed that the tear proteome of patients with KC differed from controls by more than one-third of the total proteins identified, highlighting the relationship of the proteins only expressed in KC tears with processes of cell death, oxidative damage, and inflammation. The underexpression of proteins involved in iron pathways might support the iron imbalance as a contributing factor to cellular damage and death in KC disease.
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Affiliation(s)
- Maite López-López
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.,Department of Surgery and Medical-Surgical Specialties, Faculty of Optics and Optometry, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Uxía Regueiro
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.,Department of Surgery and Medical-Surgical Specialties, Faculty of Optics and Optometry, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Susana Belén Bravo
- Proteomic Unit, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | | | - Carmen Pena
- Proteomic Unit, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Elío Díez-Feijoo
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.,Department of Surgery and Medical-Surgical Specialties, Faculty of Optics and Optometry, University of Santiago de Compostela, Santiago de Compostela, Spain.,Galician Institute of Ophthalmology (INGO), Conxo Provincial Hospital, Santiago de Compostela, Spain
| | - Pablo Hervella
- Neuroimaging and Biotechnology Group (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Isabel Lema
- Corneal Neurodegeneration Group (RENOIR), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.,Department of Surgery and Medical-Surgical Specialties, Faculty of Optics and Optometry, University of Santiago de Compostela, Santiago de Compostela, Spain.,Galician Institute of Ophthalmology (INGO), Conxo Provincial Hospital, Santiago de Compostela, Spain
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11
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Das AV, Pillutla LN, Chaurasia S. Clinical profile and demographic distribution of pellucid marginal corneal degeneration in India: A study of 559 patients. Indian J Ophthalmol 2021; 69:3488-3493. [PMID: 34826981 PMCID: PMC8837343 DOI: 10.4103/ijo.ijo_553_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose: The aim of this study was to describe the clinical profile and demographic distribution of pellucid marginal corneal degeneration (PMD) in patients presenting to a multitier ophthalmology hospital network in India. Methods: This cross-sectional hospital-based study included 2,470,793 new patients presenting between September 2012 and September 2020 (~8 years period). Patients with a clinical diagnosis of PMD in at least one eye were included as cases. The data were collected using an electronic medical record system. Results: Overall, 559 (0.02%) new patients were diagnosed with PMD. The prevalence rates were 0.004% in children (age <16 years) and 0.03% in adults. The majority of patients were males (70.13%) with the bilateral affliction (77.1%). The mean age of the patients was 37.91 ± 13.19 years. The majority (30.23%) of the patients were between 31 and 40 years of age. A significant number of patients were from higher socioeconomic status (93.74%) and from the urban region (45.08%). Of the 990 eyes, the most common clinical signs were ectasia/thinning (58.99%), corneal scar (17.47%), and corneal hydrops (1.01%). The majority of the eyes (87.97%) were managed with either spectacles or contact lenses. Among those who had surgical intervention, collagen cross-linking was the most performed procedure (5.25%) followed by cataract surgery (4.14%). Conclusion: PMD is a rare disease affecting patients seeking eye care in India. It commonly affects adult males and is bilateral in nature. The disease progression is slow and usually occurs beyond 3 years. Conservative management is more common than surgical intervention.
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Affiliation(s)
- Anthony V Das
- Department of eyeSmart EMR and AEye, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Lalitha N Pillutla
- Department of eyeSmart EMR and AEye, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Sunita Chaurasia
- Cornea and Anterior Segment Services, L V Prasad Eye Institute, Hyderabad, Telangana, India
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12
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Sun M, Zafrullah N, Adams S, Devaux F, Avila MY, Ziebarth N, Margo CE, Koch M, Espana EM. Collagen XIV Is an Intrinsic Regulator of Corneal Stromal Structure and Function. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:2184-2194. [PMID: 34560063 DOI: 10.1016/j.ajpath.2021.08.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/04/2021] [Accepted: 08/16/2021] [Indexed: 12/01/2022]
Abstract
Collagen XIV is poorly characterized in the body, and the current knowledge of its function in the cornea is limited. The aim of the current study was to elucidate the role(s) of collagen XIV in regulating corneal stromal structure and function. Analysis of collagen XIV expression, temporal and spatial, was performed at different postnatal days (Ps) in wild-type C57BL/6 mouse corneal stromas and after injury. Conventional collagen XIV null mice were used to inquire the roles that collagen XIV plays in fibrillogenesis, fibril packing, and tissue mechanics. Fibril assembly and packing as well as stromal organization were evaluated using transmission electron microscopy and second harmonic generation microscopy. Atomic force microscopy was used to assess stromal stiffness. Col14a1 mRNA expression was present at P4 to P10 and decreased at P30. No immunoreactivity was noted at P150. Abnormal collagen fibril assembly with a shift toward larger-diameter fibrils and increased interfibrillar spacing in the absence of collagen XIV was found. Second harmonic generation microscopy showed impaired fibrillogenesis in the collagen XIV null stroma. Mechanical testing suggested that collagen XIV confers stiffness to stromal tissue. Expression of collagen XIV is up-regulated following injury. This study indicates that collagen XIV plays a regulatory role in corneal development and in the function of the adult cornea. The expression of collagen XIV is recapitulated during wound healing.
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Affiliation(s)
- Mei Sun
- Cornea and External Disease, Department of Ophthalmology, University of South Florida, Morsani College of Medicine, Tampa, Florida
| | - Nabeel Zafrullah
- Cornea and External Disease, Department of Ophthalmology, University of South Florida, Morsani College of Medicine, Tampa, Florida
| | - Sheila Adams
- Cornea and External Disease, Department of Ophthalmology, University of South Florida, Morsani College of Medicine, Tampa, Florida
| | - Floriane Devaux
- Biomedical Atomic Force Microscopy Laboratory, Department of Biomedical Engineering, College of Engineering, University of Miami, Miami, Florida
| | - Marcel Y Avila
- Department of Ophthalmology, Universidad Nacional de Colombia, Bogota, Colombia
| | - Noel Ziebarth
- Biomedical Atomic Force Microscopy Laboratory, Department of Biomedical Engineering, College of Engineering, University of Miami, Miami, Florida; Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, Florida
| | - Curtis E Margo
- Cornea and External Disease, Department of Ophthalmology, University of South Florida, Morsani College of Medicine, Tampa, Florida
| | - Manuel Koch
- Institute for Dental Research and Oral Musculoskeletal Biology, Center for Biochemistry, University of Cologne, Cologne, Germany
| | - Edgar M Espana
- Cornea and External Disease, Department of Ophthalmology, University of South Florida, Morsani College of Medicine, Tampa, Florida; Department of Molecular Pharmacology and Physiology, University of South Florida, Morsani College of Medicine, Tampa, Florida.
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13
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López-López M, Regueiro U, Bravo SB, Chantada-Vázquez MDP, Varela-Fernández R, Ávila-Gómez P, Hervella P, Lema I. Tear Proteomics in Keratoconus: A Quantitative SWATH-MS Analysis. Invest Ophthalmol Vis Sci 2021; 62:30. [PMID: 34431975 PMCID: PMC8399462 DOI: 10.1167/iovs.62.10.30] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Purpose To elucidate dysregulated proteins in keratoconus (KC) to provide a better understanding of the molecular mechanisms that lead to the development of the disease using sequential window acquisition of all theoretical mass spectra (SWATH-MS) as a protein quantification tool of the tear proteomic profile. Methods Prospective cross-sectional study that includes 25 keratoconic eyes and 25 healthy eyes. All participants underwent a clinical, tomographic, and aberrometric exam. Tear sample was collected using Schirmer strips and analyzed by liquid chromatography with tandem mass spectrometry. SWATH-MS was used as a quantification tool of the tear proteomic profile. The expression of the quantified proteins was compared between groups, and the biological and molecular functions of the dysregulated proteins as well as their functional relationships were studied by in silico analysis. Results A total of 203 proteins were quantified in tear samples of patients with KC and control participants, of which 18 showed differential expression between groups (P < 0.05). An increase in the expression of 7 proteins and a decrease in the expression of 11 proteins were observed. Protein–protein interactions and gene ontology analysis showed the involvement of these dysregulated proteins in structural, inflammatory-immune, iron homeostasis, oxidative stress, and extracellular matrix proteolysis processes. Conclusions Tear protein quantification has revealed the dysregulation of proteins involved in biological processes previously associated with KC. Among them, iron homeostasis should be highlighted as a relevant pathway in the KC pathophysiology, and it should be taken into account in the development of therapeutic targets to cope with tissue damage derived from iron accumulation and toxicity.
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Affiliation(s)
- Maite López-López
- Department of Surgery and Medical-Surgical Specialties. Faculty of Optics and Optometry, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.,Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Uxía Regueiro
- Department of Surgery and Medical-Surgical Specialties. Faculty of Optics and Optometry, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.,Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Susana B Bravo
- Proteomic Unit, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | | | - Rubén Varela-Fernández
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.,Department of Pharmacology, Pharmacy and Pharmaceutical Technology. Universidade de Santiago de Compostela (USC), Campus Vida, Santiago de Compostela, Spain
| | - Paulo Ávila-Gómez
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Pablo Hervella
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Isabel Lema
- Department of Surgery and Medical-Surgical Specialties. Faculty of Optics and Optometry, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.,Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.,Instituto Galego de Oftalmoloxía (INGO), Hospital Provincial de Conxo, Santiago de Compostela, Spain
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14
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Abstract
ABSTRACT The advent of refractive surgery and corneal cross-linking for ectatic disease has further highlighted the need to recognize early or subclinical ectatic disease. Historical systems depend on anterior corneal changes that occur late in the disease course and are commonly associated with visual loss. Tomographic imaging allows for the acquisition of posterior corneal surface data and corneal thickness distribution. This led to the development of modalities to diagnose early or subclinical keratoconus and to screen patients for refractive surgery.This article reviews the modern methods for assessing changes in posterior corneal surface and pachymetric distribution, now accepted by the major cornea societies to be the hallmarks of ectatic disease. Screening tools utilized by the commonly used tomographic imaging devices are discussed, and the difference between screening for ectasia and diagnosing keratoconus is highlighted. The Belin ABCD staging and classification system and the ABCD Progression Display are reviewed as a new grading and monitoring system that can be used for earlier intervention and prevention of visual loss in keratoconus.
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15
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Kalra N, Asif MI, Bafna RK, Sharma N, Sinha R. Posterior Chamber Phakic Intraocular Lens Implantation for Refractive Correction in Corneal Ectatic Disorders: A Review. J Refract Surg 2021; 37:351-359. [PMID: 34044697 DOI: 10.3928/1081597x-20210115-03] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To summarize the indications and outcomes of posterior chamber phakic intraocular lens (PIOL) implantation in corneal ectasias including keratoconus, pellucid marginal degeneration (PMD), post-refractive surgery, and post-keratoplasty ectasias. METHODS A review of the literature was conducted using the relevant keywords from various databases up to August 15, 2020. All pertinent studies were reviewed, and the relevant articles were studied in detail for efficacy, stability, predictability, and safety outcomes. In addition, visual quality, corneal biomechanical outcomes, complications, the role of posterior chamber PIOL in combination treatment, and comparison of posterior chamber PIOL with other PIOLs for ectasias were also evaluated. RESULTS A total of 30 relevant studies (13 prospective, 13 retrospective, 4 case reports) on the subject were studied and summarized. All studies showed a favorable refractive outcome. Quality of vision remained unaffected and no significant complications were reported in any of the studies. CONCLUSIONS Posterior chamber PIOLs represent a viable option in the treatment of mild to moderate and stable corneal ectasia in patients with contact lens intolerance who have low irregular astigmatism, a clear central cornea, and good preoperative corrected distance visual acuity. [J Refract Surg. 2021;37(5):351-359.].
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16
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Jacobs DS, Carrasquillo KG, Cottrell PD, Fernández-Velázquez FJ, Gil-Cazorla R, Jalbert I, Pucker AD, Riccobono K, Robertson DM, Szczotka-Flynn L, Speedwell L, Stapleton F. CLEAR - Medical use of contact lenses. Cont Lens Anterior Eye 2021; 44:289-329. [PMID: 33775381 DOI: 10.1016/j.clae.2021.02.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 02/01/2021] [Indexed: 12/11/2022]
Abstract
The medical use of contact lenses is a solution for many complex ocular conditions, including high refractive error, irregular astigmatism, primary and secondary corneal ectasia, disfiguring disease, and ocular surface disease. The development of highly oxygen permeable soft and rigid materials has extended the suitability of contact lenses for such applications. There is consistent evidence that bandage soft contact lenses, particularly silicone hydrogel lenses, improve epithelial healing and reduce pain in persistent epithelial defects, after trauma or surgery, and in corneal dystrophies. Drug delivery applications of contact lens hold promise for improving topical therapy. Modern scleral lens practice has achieved great success for both visual rehabilitation and therapeutic applications, including those requiring retention of a tear reservoir or protection from an adverse environment. This report offers a practical and relevant summary of the current evidence for the medical use of contact lenses for all eye care professionals including optometrists, ophthalmologists, opticians, and orthoptists. Topics covered include indications for use in both acute and chronic conditions, lens selection, patient selection, wear and care regimens, and recommended aftercare schedules. Prevention, presentation, and management of complications of medical use are reviewed.
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Affiliation(s)
- Deborah S Jacobs
- Massachusetts Eye & Ear, Cornea and Refractive Surgery Service, Harvard Medical School, Boston, MA, USA.
| | | | | | | | | | | | | | | | | | - Loretta Szczotka-Flynn
- Department of Ophthalmology & Visual Science, Case Western Reserve University, Cleveland, OH, USA
| | - Lynne Speedwell
- Great Ormond Street Hospital for Children NHS Trust, Moorfields Eye Hospital, London, UK
| | - Fiona Stapleton
- School of Optometry and Vision Science, UNSW Sydney, Australia
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17
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Regueiro U, López-López M, Hervella P, Sobrino T, Lema I. Corneal and conjunctival alteration of innate immune expression in first-degree relatives of keratoconus patients. Graefes Arch Clin Exp Ophthalmol 2021; 259:459-467. [PMID: 32949300 DOI: 10.1007/s00417-020-04929-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/01/2020] [Accepted: 09/10/2020] [Indexed: 01/18/2023] Open
Abstract
PURPOSE The innate immune toll-like receptors 2 (TLR2) and 4 (TLR4) may play a key role in the physiopathology of keratoconus (KC). Therefore, the aim of this study was to compare TLR2/TLR4 expression in corneal and conjunctival epithelial cells between healthy first-degree relatives of patients with KC and healthy controls as well as KC patients. METHODS Case-control study in 72 healthy eyes of 36 control subjects, 53 eyes of 27 first-degree relatives, and 109 eyes with KC (60 patients). All participants were subjected to a clinical, topographic, aberrometric, and tomographic examination with extraction of corneal and conjunctival epithelial cells through scraping. TLR2/TLR4 expression was measured by flow cytometry, and was compared among controls, first-degree relatives, and KC patients. The relationship between TLR expression and epidemiological-clinical variables or topographic-aberrometric-tomographic parameters was also analyzed. RESULTS Mean TLR2/TLR4 expression showed a significant gradual increase among groups: controls < first-degree relatives < KC patients. Mean expression of TLR2 in corneal epithelial cells and both TLR2/TLR4 in conjunctival epithelial cells were significantly higher in relatives than in controls (p = 0.026, p < 0.001, and p = 0.031, respectively). Sex, age, allergic disease, eye itching, rubbing, and topographic-aberrometric-tomographic parameters were not associated to TLR2/TLR4 expression in relatives. TLR2 conjunctival expression was independently associated to relatives (OR 1.001; CI 95% 1.000-1.002, p = 0.043) after adjustment by sex, age, and rubbing. CONCLUSION TLR2 and TLR4 are overexpressed in corneal and conjunctival epithelial cells of KC relatives compared with controls. Both biomarkers may monitor early ocular changes in first-degree relatives who not show any abnormal clinical-topographic-aberrometric-tomographic parameters.
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Affiliation(s)
- Uxía Regueiro
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.,Facultade de Óptica e Optometría, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Maite López-López
- Facultade de Óptica e Optometría, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Pablo Hervella
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Tomás Sobrino
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.
| | - Isabel Lema
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain. .,Facultade de Óptica e Optometría, Universidade de Santiago de Compostela, Santiago de Compostela, Spain. .,Instituto Galego de Oftalmoloxía (INGO), Hospital Provincial de Conxo, Santiago de Compostela, Spain.
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18
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Matalia H, Nandini C, Matalia J. Long-term outcome of custom toric intraocular lens for treating high astigmatism in case of cataract associated with pellucid marginal corneal degeneration. Indian J Ophthalmol 2020; 68:3082-3084. [PMID: 33245061 PMCID: PMC7857004 DOI: 10.4103/ijo.ijo_2943_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Pellucid marginal corneal degeneration (PMCD) is a progressive corneal ectasia that ultimately results in high regular astigmatism and correction of this astigmatism is always challenging. However, when a PMCD patient develops a cataract, it provides a golden opportunity to treat this coexisting astigmatism with toric intraocular lens (IOL) implantation. Regular toric IOLs would correct astigmatism only up to 6 diopters in the IOL plane but higher astigmatism would require customization of such IOLs. Our case report describes the long term outcomes of customized toric IOL to tackle this high astigmatism during cataract surgery in PMCD cases.
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Affiliation(s)
- Himanshu Matalia
- Department of Cornea and Refractive Surgery, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Chinnappaiah Nandini
- Department of Cornea and Refractive Surgery, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Jyoti Matalia
- Department of Pediatric Ophthalmology and Neurophthalmology, Narayana Nethralaya, Bangalore, Karnataka, India
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19
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Mohr N, Shajari M, Krause D, Kassumeh S, Siedlecki J, Priglinger SG, Mayer WJ, Luft N. Pellucid marginal degeneration versus keratoconus: distinction with wide-field SD-OCT corneal sublayer pachymetry. Br J Ophthalmol 2020; 105:1638-1644. [PMID: 33055086 DOI: 10.1136/bjophthalmol-2020-316496] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 07/11/2020] [Accepted: 09/15/2020] [Indexed: 11/03/2022]
Abstract
PURPOSE To evaluate the capability of wide-field spectral-domain optical coherence tomography (SD-OCT) corneal sublayer pachymetry to distinguish between keratoconus and pellucid marginal degeneration (PMD). METHODS This prospective cross-sectional study included 69 eyes (59 with keratoconus and 10 with PMD) of 69 patients. All patients were examined three subsequent times with the RTVue XR system. Pachymetry maps of the total cornea (CT), the epithelium (ET) and the stroma were generated using the onboard software. For analysis of reliability, the coefficients of variation and intraclass correlation coefficients (ICC) were calculated. Receiver operating characteristic analyses were performed to elaborate the most accurate pachymetric parameters for distinguishing between PMD and keratoconus. RESULTS Overall repeatability of (sublayer) pachymetry was comparably good in both keratoconus (ICC ranging between 0.827 and 0.986) and PMD (ICC ranging between 0.753 and 0.998). Measurement reliability in keratoconic eyes was a negative function of Kmax (p<0.05). As compared with keratoconus, PMD exhibited higher CT (526±31 µm vs 503±30 µm; p=0.02) and ET (56±7 µm vs 51±5 µm; p=0.02) in the inferotemporal 2-5 mm sector as well as lower ET in the inferior 7-9 mm sector (52±5 µm vs 57±5 µm; p<0.01). The calculated ratio between CT in the inferotemporal 2-5 mm and in the inferior 7-9 mm sector yielded the highest diagnostic accuracy for distinguishing between PMD and keratoconus with an area under the curve of 0.977 and an optimal cut-off value of 0.90. CONCLUSION Wide-field SD-OCT corneal sublayer pachymetry showed good reliability in PMD and keratoconus and may be useful to differentiate between the two ectatic diseases.
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Affiliation(s)
- Niklas Mohr
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany
| | - Mehdi Shajari
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.,Department of Ophthalmology, Goethe-University, Frankfurt am Main, Germany
| | - Daniel Krause
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany
| | - Stefan Kassumeh
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany
| | - Jakob Siedlecki
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.,SMILE Eyes Clinic, Linz, Austria
| | - Siegfried G Priglinger
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.,SMILE Eyes Clinic, Linz, Austria
| | - Wolfgang J Mayer
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany
| | - Nikolaus Luft
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany .,SMILE Eyes Clinic, Linz, Austria
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20
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Regueiro U, Pérez-Mato M, Hervella P, Campos F, Sobrino T, Lema I. Toll-like receptors as diagnostic targets in pellucid marginal degeneration. Exp Eye Res 2020; 200:108211. [PMID: 32890481 DOI: 10.1016/j.exer.2020.108211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/06/2020] [Accepted: 08/31/2020] [Indexed: 12/30/2022]
Abstract
The main purpose of this study is to evaluate the diagnostic role of Toll-like receptors 2 (TLR2) and 4 (TLR4) expression in corneal and conjunctival epithelial cells of eyes with pellucid marginal degeneration (PMD) compared to keratoconus patients (KC) and control subjects. A prospective case-control study in 29 PMD eyes, 109 KC eyes and 72 healthy eyes was done. All participants were subjected to a clinical, topographic, aberrometric and tomographic exam with extraction of corneal and conjunctival epithelial cells through scraping. The TLR2 and TLR4 expression was measured with flow cytometry. Receiver operating characteristic (ROC) curve analysis was used to determine the most appropriate cutoff point for predicting the risk of PMD and KC. Correlations between TLR2/TLR4 expression and the severity of PMD/KC were evaluated. A TLRs follow-up review was made 19 ± 4 months after to the first review. As result, mean expression of TLR2 and TLR4 in both corneal and conjunctival epithelial cells was significantly higher in eyes with corneal ectasia (PMD and KC) than in control eyes (all p < 0.05). Conjunctival TLR4 expression showed the highest capacity to diagnose the existence of PMD (odd ratio 42.84; 95% confidence interval:6.20-296.20; p < 0.0001) after adjusting by eye rubbing and steeper corneal meridian. Moreover, we found an association between the TLR2/TLR4 overexpression with the severity of the PMD and KC measured by corneal topographic, aberrometric and tomographic quantitative parameters (all p < 0.05). Differences on TLR2/TLR4 expression between study groups were maintained during the follow-up period. In conclusion, the TLR2/TLR4 overexpression in corneal and conjunctival epithelial cells of PMD and KC patients compared to healthy control subjects have demonstrated their role as diagnostic target in both corneal ectatic disorders.
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Affiliation(s)
- Uxía Regueiro
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain; Facultade de Óptica e Optometría, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - María Pérez-Mato
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Pablo Hervella
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Francisco Campos
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Tomás Sobrino
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.
| | - Isabel Lema
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain; Facultade de Óptica e Optometría, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain; Instituto Galego de Oftalmoloxía (INGO), Hospital Provincial de Conxo, Santiago de Compostela, Spain.
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21
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Aberrometric outcome of customized toric IOL in cataract with very high corneal astigmatism due to pellucid marginal degeneration. J Cataract Refract Surg 2020; 46:1308-1311. [PMID: 32541368 DOI: 10.1097/j.jcrs.0000000000000278] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A case of pellucid marginal degeneration (PMD) with cataract where a customized high-power toric IOL was implanted is reported. The patient had preoperative corneal astigmatism of 13.96 diopters (D), and a customized toric IOL of 19 D toricity was implanted; postoperative visual acuity was 6/9 on Snellen chart. The visual quality and aberrometric outcome were assessed with a ray-tracing aberrometer. The toric IOL gave not only a better uncorrected visual acuity but also better quality of vision in this patient with corneal astigmatism due to PMD.
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22
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de Almeida Ferreira G, Coral Ghanem V, Coral Ghanem R. Late progressive corneal flattening, haze and visual loss after eccentric crosslinking for Pellucid marginal degeneration. Am J Ophthalmol Case Rep 2020; 18:100621. [PMID: 32140613 PMCID: PMC7044711 DOI: 10.1016/j.ajoc.2020.100621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 11/20/2019] [Accepted: 02/17/2020] [Indexed: 11/17/2022] Open
Abstract
Purpose Observation Conclusion and Importance
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23
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Pellucid marginal degeneration: Detection, discrimination from other corneal ectatic disorders and progression. Cont Lens Anterior Eye 2019; 42:341-349. [DOI: 10.1016/j.clae.2018.11.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/07/2018] [Accepted: 11/15/2018] [Indexed: 02/07/2023]
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Transepithelial Phototherapeutic Keratectomy Followed by Corneal Collagen Crosslinking for the Treatment of Pellucid Marginal Degeneration: Long-term Results. Cornea 2019; 38:980-985. [PMID: 31107284 DOI: 10.1097/ico.0000000000002003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE To evaluate visual, refractive, topographic, and aberrometric outcomes of transepithelial phototherapeutic keratectomy (PTK) + corneal collagen crosslinking in the treatment of pellucid marginal degeneration. METHODS This retrospective study includes 20 eyes of 15 patients with pellucid marginal degeneration treated with transepithelial PTK + accelerated corneal collagen crosslinking. Visual acuity, refraction, topographic keratometry, pachymetry, and aberrations were recorded pretreatment and 6, 12, 24, and 36 months after treatment. RESULTS Stabilization in visual acuity was observed throughout the 36 months of follow-up (P > 0.05). The cylindrical value was significantly lower (P < 0.05) during the follow-up compared with the baseline (4.97 ± 2.00, 3.86 ± 2.01, 3.92 ± 2.27, 2.87 ± 1.70, and 3.28 ± 3.12 D at the baseline and postoperative 6th, 12th, 24th, and 36th month, respectively). Spherical equivalent was significantly lower at the 24th (P = 0.02) and 36th month (P = 0.01) follow-up intervals. A significant decrease (P < 0.05) in average keratometry readings was observed in all follow-up points (47.12 ± 4.66, 46.65 ± 4.38, 46.57 ± 4.57, 46.46 ± 4.81, and 46.27 ± 4.46 D, respectively). The maximum keratometry value remained stable (P > 0.05) in all visits (64.30 ± 10.70, 63.49 ± 10.05, 62.97 ± 9.50, 63.33 ± 10.06, and 62.27 ± 10.36 D, respectively). The Baiocchi Calossi Versaci index was significantly lower (P < 0.05) at all follow-up points compared with the baseline (3.21 ± 1.93, 2.99 ± 1.96, 2.96 ± 1.93, 2.82 ± 1.95, and 2.86 ± 1.99 μm, respectively). Central and minimum corneal thicknesses were significantly lower (P ≤ 0.01) compared with the baseline throughout the follow-up. Higher order aberration, trefoil, coma, and spherical aberration values remained stable during the follow-up compared with the baseline (P > 0.05). CONCLUSIONS The combination of transepithelial PTK with accelerated corneal collagen crosslinking seems to be an effective treatment in patients with pellucid marginal degeneration in the long-term.
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Garcia-Ferrer FJ, Akpek EK, Amescua G, Farid M, Lin A, Rhee MK, Varu DM, Musch DC, Mah FS, Dunn SP. Corneal Ectasia Preferred Practice Pattern®. Ophthalmology 2019; 126:P170-P215. [DOI: 10.1016/j.ophtha.2018.10.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 10/09/2018] [Indexed: 02/07/2023] Open
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Nasrin F, Iyer RV, Mathews SM. Simultaneous Estimation of Corneal Topography, Pachymetry, and Curvature. IEEE TRANSACTIONS ON MEDICAL IMAGING 2018; 37:2463-2473. [PMID: 29994760 DOI: 10.1109/tmi.2018.2836304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Identification of objective criteria to correctly diagnose ectatic diseases of the cornea or to detect early stages of corneal ectasia is of great interest in ophthalmology and optometry. Metrics for diagnosis typically employed are curvature maps (axial/sagittal, tangential); elevation map of the anterior surface of the cornea with respect to a reference sphere; and pachymetry (thickness) map of the cornea. We present evidence that currently used curvature maps do not represent the actual curvatures (principal or mean) in a human cornea. A novel contribution of this paper is the computation of the true mean curvature over every point of a central region of the cornea. We show that the true mean curvature can accurately identify the location of the ectasia. We present a quartic smoothing spline algorithm for the simultaneous computation of elevation maps for anterior and posterior corneal surfaces, pachymetry, and true mean curvature. The input to the algorithm is data from a single measurement from imaging devices such as an anterior segment optical coherence tomographer or a Scheimpflug imager. We show that a different combination of metrics is useful for the diagnosis of existing ectasia (true mean curvature and anterior elevation map) as opposed to subclinical ectasia (pachymetry and posterior elevation map). We compare our results with existing algorithms, and present applications to a normal cornea, a forme fruste keratoconic cornea, and an advanced keratoconic cornea.
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Tekin K, Koc M. Corneal hysteresis and corneal resistance factor in pellucid marginal degeneration. J Curr Ophthalmol 2018; 30:186. [PMID: 29988894 PMCID: PMC6033774 DOI: 10.1016/j.joco.2017.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 11/10/2017] [Indexed: 11/18/2022] Open
Affiliation(s)
- Kemal Tekin
- Kars State Hospital, Kars, Turkey.,Ulucanlar Eye Training and Research Hospital, Ophthalmology Department, Ankara, Turkey
| | - Mustafa Koc
- Ulucanlar Eye Training and Research Hospital, Ophthalmology Department, Ankara, Turkey
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Repeat Keratoplasty for Failed Deep Anterior Lamellar Keratoplasty in Keratoconus: Incidence, Indications, and Outcomes. Cornea 2017; 46:325-326. [PMID: 28257387 DOI: 10.1097/ico.0000000000001169] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To analyze the incidence, indications, and clinical outcomes of penetrating keratoplasty (PK) and repeat deep anterior lamellar keratoplasty (DALK) after failed DALK for keratoconus. METHODS This retrospective interventional case series reviewed the medical records of patients with keratoconus who underwent DALK and were followed up for at least 1 year. Patients who underwent PK or repeat DALK for failed DALK were identified. The incidence, indications, and clinical outcomes after repeat keratoplasty were assessed. RESULTS A total of 382 consecutive eyes with keratoconus underwent DALK over a 9-year period. Graft failure was observed in 14 eyes (3.7%). The reasons for the graft failure included nonhealing epithelial defects (n = 1), pseudoanterior chamber (n = 2), patient dissatisfaction with vision (n = 4), interface opacification (n = 4), high astigmatism (n = 1), and recurrence of keratoconus in the graft (n = 2). Of these 14 eyes with graft failure, 12 eyes underwent PK (n = 11) or repeat DALK (n = 1). At the most recent examination, which was performed 49.7 ± 25.2 months after the secondary graft, all regrafts were clear. There was no significant difference between eyes with clear first grafts and eyes that underwent PK or repeat DALK in visual outcomes at the final examination. Graft rejection was the most common complication, which was encountered in 75% of the regrafts. CONCLUSIONS The prognosis for repeat keratoplasty was excellent, and the outcomes of secondary grafts were comparable to those of primary DALK grafts. However, the rate of rejection with secondary grafts was high, necessitating close follow-up after PK and repeat DALK performed for failed DALK.
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Koc M, Tekin K, Inanc M, Kosekahya P, Yilmazbas P. Crab claw pattern on corneal topography: pellucid marginal degeneration or inferior keratoconus? Eye (Lond) 2017; 32:11-18. [PMID: 28937143 DOI: 10.1038/eye.2017.198] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 08/01/2017] [Indexed: 11/09/2022] Open
Abstract
PurposeTo evaluate the topographic, tomographic, and densitometric properties of patients with pellucid marginal degeneration (PMD) and inferior keratoconus.Patients and methodsRetrospective, comparative case series. Forty-seven eyes of 32 patients with crab claw patterns were identified from 2751 patients with corneal ectasia. They were divided into two groups, inferior keratoconus and PMD, based on clinical findings. The topographic, tomographic, and densitometric measurements were analyzed.ResultsPMD was detected in 11 eyes of eight patients (mean age 50.2±11.1 years), and inferior keratoconus was detected in 36 eyes of 24 patients (mean age 34.7±10.1 years). The control group consisted of 40 patients (33.1±4.6 years). The thinnest corneal point and maximum anterior and posterior elevation points were located lower in the PMD than in the inferior keratoconus (P<0.01). In the PMD, all deviation indices were higher than the controls (P<0.01), whereas the deviation indices, except Dt (P=0.960), were lower than the inferior keratoconus (P<0.01). The densitometry values of PMD were significantly higher than those of the controls in all zones and layers (P<0.01) and significantly higher than the densitometry values of inferior keratoconus in the 6-10 and 10-12 mm zones (P<0.05).ConclusionThere is a higher probability of a patient with crab claw pattern on the topography of having inferior keratoconus than having PMD. Therefore, analyzing only the anterior corneal surface is not sufficient in differential diagnosis. Tomographic and densitometric evaluations may facilitate the differential diagnosis.
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Affiliation(s)
- M Koc
- Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - K Tekin
- Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - M Inanc
- Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - P Kosekahya
- Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - P Yilmazbas
- Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
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Sedaghat MR, Ostadi-Moghadam H, Jabbarvand M, Askarizadeh F, Momeni-Moghaddam H, Narooie-Noori F. Corneal hysteresis and corneal resistance factor in pellucid marginal degeneration. J Curr Ophthalmol 2017; 30:42-47. [PMID: 29564407 PMCID: PMC5859559 DOI: 10.1016/j.joco.2017.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 07/02/2017] [Accepted: 08/01/2017] [Indexed: 01/09/2023] Open
Abstract
Purpose To evaluate and compare corneal hysteresis (CH) and corneal resistance factor (CRF) in pellucid marginal degeneration (PMD), keratoconus (KCN), and normal eyes using the Ocular Response Analyzer (ORA). Methods In this retrospective study, corneal biomechanical parameters were measured in patients with PMD (n = 102) and KCN (n = 202) and normal subjects (n = 208) using the ORA. Data, including full patient history as well as the results of refraction, slit-lamp biomicroscopy, Pentacam HR (Oculus), and ORA (Reichert; Buffalo, New York, USA), were collected from medical records. Also, the data of only one eye per individual were selected for the analysis. The inclusion criteria for PMD and KCN groups were a reliable diagnosis of these ectatic disorders based on the clinical and corneal tomographic findings. CH, CRF, CH–CRF, intraocular pressure (IOP) measurements were assessed for each subject. Data were analyzed with SPSS and MedCalc using the ANOVA, Pearson Correlation, and receiver operating characteristic (ROC) curve analysis. Results The mean CH was 8.91 mmHg ± 1.05 [standard deviation (SD)], 8.43 ± 0.78, and 10.89 ± 1.08 in the PMD, KCN, and normal group, respectively. Also, the mean CRF was 8.21 ± 1.35, 7.19 ± 1.11, and 10.69 ± 1.41 in the PMD, KCN, and normal group, respectively. ANOVA showed differences in the mean CH, CRF, and CH–CRF between three groups (P < 0.001). Also, ROC curve analysis showed the cut-off points ≤9.5, ≤9.5, and >1.3 mmHg for CH, CRF, and CH–CRF in the PMD group, respectively. For biomechanical parameters in PMD eyes, CRF had the highest sensitivity (75.49%) while the greatest area under the ROC curve (AUC) was seen for CH (0.903). Moreover, central corneal thickness (CCT) showed no correlation with CH (P = 0.30, r = −0.104) or CRF (P = 0.75, r = 0.033) in the PMD group. Conclusions This study presented the values of corneal biomechanics for PMD using the ORA. The results of the ORA were markedly different between PMD, KCN, and normal eyes.
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Affiliation(s)
- Mohamad Reza Sedaghat
- Cornea Research Center, Khatam-Al-Anbia Hospital, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hadi Ostadi-Moghadam
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.,Refractive Errors Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mahmoud Jabbarvand
- Ophthalmology Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Farshad Askarizadeh
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.,Refractive Errors Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hamed Momeni-Moghaddam
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.,Refractive Errors Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Foroozan Narooie-Noori
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.,Refractive Errors Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
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Bikbov MM, Surkova VK, Khalimov AR, Usubov EL. [Results of corneal crosslinking for pellucid marginal corneal degeneration]. Vestn Oftalmol 2017; 133:58-66. [PMID: 28745658 DOI: 10.17116/oftalma2017133358-64] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
AIM to evaluate the clinical effectiveness of crosslinking in patients with progressive pellucid marginal corneal degeneration (PMCD). MATERIAL AND METHODS A total of 9 patients (16 eyes) with progressive PMCD were treated by standard crosslinking. The cornea was saturated with Dextralink solution and UV-A irradiated at 3 mW/cm2 for 30 minutes. The follow-up period was 12 months. RESULTS One month after treatment, there was a slight decrease in uncorrected and best corrected visual acuity (UCVA and BCVA) - from 0.08±0.03 and 0.4±0.15 preoperatively down to 0.06±0.02 and 0.3±0.07, respectively, caused by pseudohaze of the cornea. Keratometric parameters (the average refractive power of the cornea, corneal astigmatism, and corneal thickness) did not change significantly. The demarcation line was identified in 56% of cases. By the 3-month follow-up, UCVA and BCVA improved up to 0.1±0.07 and 0.52±0.1, respectively. The refractive power of the cornea decreased by 2.0 diopters and corneal astigmatism - by 0.7 diopters reaching 46.8±2.7 and 5.1±1.3 diopters, respectively (p≤0.04). Central corneal thickness decreased by an average of 29 microns. The demarcation line remained visible in 25% of cases. At 6 months, BCVA averaged 0.58±0.13, at that, 56% of eyes gained 1 line and 31% - 2 lines. The refractive power of the cornea decreased down to 45.7±1.6 diopters, corneal astigmatism - down to 4.8±1.5 diopters. The demarcation line was not detected. At 1 year, there were no significant changes in the average values of optometric indices as compared to the 6-month period. Сonclusion. Pellucid marginal corneal degeneration should be regarded as a kind of primary ectasia, often bilateral and notable for its characteristic clinical picture and late onset. In progressive disease, photochemical crosslinking of the cornea contributes to the improvement of optometric parameters and stabilization of the process.
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Affiliation(s)
- M M Bikbov
- Ufa Eye Research Institute, Academy of Sciences of the Republic of Bashkortostan, 90 Pushkin St., Ufa, Russia, 450008
| | - V K Surkova
- Ufa Eye Research Institute, Academy of Sciences of the Republic of Bashkortostan, 90 Pushkin St., Ufa, Russia, 450008
| | - A R Khalimov
- Ufa Eye Research Institute, Academy of Sciences of the Republic of Bashkortostan, 90 Pushkin St., Ufa, Russia, 450008
| | - E L Usubov
- Ufa Eye Research Institute, Academy of Sciences of the Republic of Bashkortostan, 90 Pushkin St., Ufa, Russia, 450008
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Clinical outcomes of scleral Misa lenses for visual rehabilitation in patients with pellucid marginal degeneration. Cont Lens Anterior Eye 2016; 39:420-424. [DOI: 10.1016/j.clae.2016.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 06/20/2016] [Accepted: 06/29/2016] [Indexed: 11/22/2022]
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National survey of pellucid marginal corneal degeneration in Japan. Jpn J Ophthalmol 2016; 60:341-8. [DOI: 10.1007/s10384-016-0462-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 05/11/2016] [Indexed: 11/25/2022]
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Pásztor D, Kolozsvári BL, Csutak A, Berta A, Hassan Z, Ujhelyi B, Gogolák P, Fodor M. Tear Mediators in Corneal Ectatic Disorders. PLoS One 2016; 11:e0153186. [PMID: 27074131 PMCID: PMC4830513 DOI: 10.1371/journal.pone.0153186] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/24/2016] [Indexed: 12/31/2022] Open
Abstract
Purpose To compare the concentrations of 11 tear mediators in order to reveal the biochemical difference between pellucid marginal degeneration (PMD) and keratoconus (KC). Methods We have designed a cross-sectional study in which patients with corneal ectasia based on slit-lamp biomicroscopy and Pentacam HR (keratometry values (K1, K2, Kmax), astigmatism, minimal radius of curvature (Rmin), corneal thickness (Apex and Min), indices (surface variation, vertical asymmetry, keratoconus, central keratoconus, height asymmetry and decentration)) were enrolled. Eyes of keratoconic patients were similar to the PMD patients in age and severity (K2, Kmax and Rmin). Non-stimulated tear samples were collected from nine eyes of seven PMD patients, 55 eyes of 55 KC patients and 24 eyes of 24 healthy controls. The mediators’ (interleukin -6, -10, chemokine ligand 5, -8, -10, matrix metalloproteinase (MMP) -9, -13, tissue inhibitor of metalloproteinases (TIMP)-1, tissue plasminogen activator, plasminogen activator inhibitor, nerve growth factor) concentrations were measured using Cytometric Bead Array. Results MMP-9 was the only mediator which presented relevant variances between the two patient groups (p = 0.005). The ratios of MMP-9 and TIMP-1 were 2.45, 0.40 and 0.23 in PMD, KC and the controls, respectively. Conclusion As far as we are aware, this is the first study that aims to reveal the biochemical differences between PMD and KC. Further studies of biomarkers to investigate the precise role of these mediators need to be defined, and it is important to confirm the observed changes in a larger study to gain further insights into the molecular alterations in PMD.
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Affiliation(s)
- Dorottya Pásztor
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Bence Lajos Kolozsvári
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Adrienne Csutak
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - András Berta
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Ziad Hassan
- Orbident Refractive Surgery and Medical Center, Debrecen, Hungary
| | - Bernadett Ujhelyi
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter Gogolák
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Mariann Fodor
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- * E-mail:
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Spadea L, Maraone G, Cagini C. Sliding Keratoplasty Followed by Transepithelial Iontophoresis Collagen Cross-linking for Pellucid Marginal Degeneration. J Refract Surg 2016; 32:47-50. [PMID: 26812714 DOI: 10.3928/1081597x-20151119-02] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 11/10/2015] [Indexed: 11/20/2022]
Abstract
PURPOSE To describe the changes in visual acuity and topographic analysis in a patient affected by advanced pellucid marginal degeneration (PMD). METHODS A 59-year-old woman with bilateral PMD who was contact lens intolerant was treated by sliding keratoplasty before and 3 months after transepithelial (epi-on) iontophoresis collagen cross-linking (I-CXL) in one eye. Corrected distance visual acuity (CDVA), spherical equivalent and cylinder refraction, corneal topography, ultrasound pachymetry, and endothelial cell count were assessed at baseline and up to 12 months postoperatively. RESULTS After 1 year of follow-up, CDVA increased from 20/200 to 20/50 and the videokeratographic patterns significantly improved. Endothelial cell counts did not change significantly (P > .05). CONCLUSIONS Sliding keratoplasty combined with I-CXL was safe and effective in the treatment of advanced PMD.
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Koçluk Y, Yalniz-Akkaya Z, Burcu A, Örnek F. Comparison of Scheimpflug imaging analysis of pellucid marginal corneal degeneration and keratoconus. Ophthalmic Res 2014; 53:21-7. [PMID: 25504087 DOI: 10.1159/000365518] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 06/25/2014] [Indexed: 11/19/2022]
Abstract
AIM To determine and compare various quantitative parameters of pellucid marginal degeneration (PMD) and keratoconus with against-the-rule astigmatism (KC-ARA) obtained by elevation-based Scheimpflug imaging and to identify characteristics that can be used to discriminate PMD from KC-ARA. SETTING Ophthalmology Clinic, Ministry of Health Ankara Training and Research Hospital, Ankara, Turkey. DESIGN Retrospective case-control study. PATIENTS AND METHODS Patients with ARA, a butterfly or crab claw pattern in the curvature maps, a kissing bird pattern in the elevation maps and the bell sign in the pachymetric maps were identified, and 60 eyes of 40 patients were chosen for the evaluation. The patients were divided into two groups: the PMD group (29 eyes of 18 patients) and the KC-ARA group (31 eyes of 22 patients). By moving the cursor manually, the pachymetric maps and Scheimpflug images were searched for a thinner location than the automatically identified thinnest location. The coordinates and thickness of this manually identified location were evaluated. RESULTS In the PMD group, 7 (24.1%) eyes did not have any thinner location than the automatically identified thinnest location on the pachymetric maps and the Scheimpflug images, and in 22 (75.8%) eyes, a thinner location, which was located more peripherally, was found by manual evaluation of the pachymetric maps or Scheimpflug images. In 9 (31.0%) eyes of these 22, the manually identified thinnest locations were visible on pachymetric maps, and in 13 (44.8%) eyes the more peripheral thinnest locations were not visible on pachymetric maps but on Scheimpflug images. In the KC group, no patients had thinner locations than the automatically identified thinnest points on the pachymetric maps and the Scheimpflug images. CONCLUSION A more peripheral thinner location than the automatically identified thinnest location exists in most of the eyes with PMD. In KC-ARA eyes, a thinner location than the automatically found thinnest point does not exist. Accordingly, a more peripheral thinner point than the identified thinnest point is a very strong indication for PMD.
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Affiliation(s)
- Yusuf Koçluk
- Ophthalmology Clinic, Ministry of Health Ankara Training and Research Hospital, Ankara, Turkey
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Moshirfar M, Edmonds JN, Behunin NL, Christiansen SM. Current Options in the Management of Pellucid Marginal Degeneration. J Refract Surg 2014; 30:474-85. [DOI: 10.3928/1081597x-20140429-02] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 03/11/2014] [Indexed: 11/20/2022]
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Abstract
Scheimpflug cross-sectioning anterior segment imaging offers significant advantages over traditional placido based curvature analysis and ultrasound pachymetry. The accurate measurement of both the anterior and posterior corneal surfaces and the anterior and posterior lens allows for the creation of a three-dimensional reconstruction of the anterior segment. Changes on both the posterior cornea and/or corneal thickness map are earlier indicators of ectatic change than would otherwise be identifiable with only anterior curvature and ultrasonic pachymetry. Scheimpflug imaging also covers significantly more of the cornea than was possible with placido based devices. This added coverage is critical in the proper diagnosis of peripheral diseases such as pellucid marginal degeneration (PMD).
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Affiliation(s)
- Michael W Belin
- Southern Arizona VA Healthcare System, University of Arizona, Tucson, Arizona, USA
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Labiris G, Giarmoukakis A, Sideroudi H, Song X, Kozobolis V, Seitz B, Gatzioufas Z. Diagnostic capacity of biomechanical indices from a dynamic bidirectional applanation device in pellucid marginal degeneration. J Cataract Refract Surg 2014; 40:1006-12. [PMID: 24774010 DOI: 10.1016/j.jcrs.2014.03.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 03/06/2014] [Accepted: 03/07/2014] [Indexed: 10/25/2022]
Abstract
PURPOSE To evaluate the diagnostic capacity of the keratoconus match index (KMI) and keratoconus match probability (KMP) classification from a dynamic bidirectional applanation device (Ocular Response Analyzer) in eyes with pellucid marginal degeneration (PMD). SETTING Department of Ophthalmology, University Clinics Saarland, Homburg, Germany. DESIGN Cross-sectional study. METHODS Pellucid marginal degeneration eligibility was confirmed by inferior peripheral thinning, corneal protrusion, and irregular astigmatism. The KMI and KMP parameters in PMD eyes (study group) were compared with those in normal eyes (control group). The KMI's overall predictive accuracy was assessed operating characteristic (ROC) curves. The relationship between KMI and corneal hysteresis (CH), the corneal resistance factor (CRF), and a series of Scheimpflug camera indices was evaluated with Spearman analysis (r). RESULTS The mean KMI in the study group (40 eyes) and control group (40 eyes) was 0.34 ± 0.43 (SD) and 0.95 ± 0.30, respectively (P<.001). The KMI correlated significantly with the CH, CRF, and most Scheimpflug camera indices. Regression analysis indicated that the index of height decentration (r = -0.877, P<.001) was the primary determinant of the KMI. Moreover, the KMP index identified 50.0%, 29.16%, and 20.83% of PMD eyes as ectatic, suspect for ectasia, and normal, respectively. The ROC curve analysis of the KMI parameter indicated a predictive accuracy of 94.8% (cutoff point 0.626; sensitivity 85.71%; specificity 90.1%). CONCLUSIONS The KMI seems to be a promising diagnostic index for PMD. In contrast, the KMP index identified a significant percentage of topographically defined PMD eyes as normal, limiting its diagnostic value in PMD. FINANCIAL DISCLOSURES No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Georgios Labiris
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece.
| | - Athanassios Giarmoukakis
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece
| | - Haris Sideroudi
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece
| | - Xuefei Song
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece
| | - Vassilios Kozobolis
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece
| | - Berthold Seitz
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece
| | - Zisis Gatzioufas
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece
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Characteristics of corneal topographic and pachymetric patterns in patients with pellucid marginal corneal degeneration. Jpn J Ophthalmol 2013; 58:131-8. [DOI: 10.1007/s10384-013-0291-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 09/20/2013] [Indexed: 10/26/2022]
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Abstract
PURPOSE OF REVIEW To review the principles and clinical applications of Scheimpflug corneal and anterior segment imaging with special relevance for laser refractive surgery. RECENT FINDINGS Computerized Scheimpflug imaging has been used for corneal and anterior segment tomography (CASTm) in different commercially available instruments. Such approach computes the three-dimensional image of the cornea and anterior segment, enabling the characterization of elevation and curvature of the front and back surfaces of the cornea, pachymetric mapping, calculation of the total corneal refractive power and anterior segment biometry. CASTm represents a major evolution for corneal and anterior segment analysis, beyond front surface corneal topography and single point central corneal thickness measurements. This approach enhances the diagnostic abilities for screening ectasia risk as well as for planning, evaluating the results, managing complications of refractive procedures, and selecting intraocular lens power, type, and design. In addition, dynamic Scheimpflug imaging has been recently introduced for in-vivo corneal biomechanical measurements and has also been used for anterior segment imaging of femtocataract surgery. SUMMARY Scheimpflug imaging has an important role for laser refractive surgery with different applications, which continuously improve due to advances in technology.
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Kanellopoulos AJ, Asimellis G. Revisiting keratoconus diagnosis and progression classification based on evaluation of corneal asymmetry indices, derived from Scheimpflug imaging in keratoconic and suspect cases. Clin Ophthalmol 2013; 7:1539-48. [PMID: 23935360 PMCID: PMC3735334 DOI: 10.2147/opth.s44741] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE To survey the standard keratoconus grading scale (Pentacam®-derived Amsler-Krumeich stages) compared to corneal irregularity indices and best spectacle-corrected distance visual acuity (CDVA). PATIENTS AND METHODS Two-hundred and twelve keratoconus cases were evaluated for keratoconus grading, anterior surface irregularity indices (measured by Pentacam imaging), and subjective refraction (measured by CDVA). The correlations between CDVA, keratometry, and the Scheimpflug keratoconus grading and the seven anterior surface Pentacam-derived topometric indices - index of surface variance, index of vertical asymmetry, keratoconus index, central keratoconus index, index of height asymmetry, index of height decentration, and index of minimum radius of curvature - were analyzed using paired two-tailed t-tests, coefficient of determination (r(2)), and trendline linearity. RESULTS The average ± standard deviation CDVA (expressed decimally) was 0.626 ± 0.244 for all eyes (range 0.10-1.00). The average flat meridian keratometry was (K1) 46.7 ± 5.89 D; the average steep keratometry (K2) was 51.05 ± 6.59 D. The index of surface variance and the index of height decentration had the strongest correlation with topographic keratoconus grading (P < 0.001). CDVA and keratometry correlated poorly with keratoconus severity. CONCLUSION It is reported here for the first time that the index of surface variance and the index of height decentration may be the most sensitive and specific criteria in the diagnosis, progression, and surgical follow-up of keratoconus. The classification proposed herein may present a novel benchmark in clinical work and future studies.
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Kanellopoulos AJ, Asimellis G. Comparison of Placido disc and Scheimpflug image-derived topography-guided excimer laser surface normalization combined with higher fluence CXL: the Athens Protocol, in progressive keratoconus. Clin Ophthalmol 2013; 7:1385-96. [PMID: 23901251 PMCID: PMC3720663 DOI: 10.2147/opth.s44745] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Background The purpose of this study was to compare the safety and efficacy of two alternative corneal topography data sources used in topography-guided excimer laser normalization, combined with corneal collagen cross-linking in the management of keratoconus using the Athens protocol, ie, a Placido disc imaging device and a Scheimpflug imaging device. Methods A total of 181 consecutive patients with keratoconus who underwent the Athens protocol between 2008 and 2011 were studied preoperatively and at months 1, 3, 6, and 12 postoperatively for visual acuity, keratometry, and anterior surface corneal irregularity indices. Two groups were formed, depending on the primary source used for topoguided photoablation, ie, group A (Placido disc) and group B (Scheimpflug rotating camera). One-year changes in visual acuity, keratometry, and seven anterior surface corneal irregularity indices were studied in each group. Results Changes in visual acuity, expressed as the difference between postoperative and preoperative corrected distance visual acuity were +0.12 ± 0.20 (range +0.60 to −0.45) for group A and +0.19 ± 0.20 (range +0.75 to −0.30) for group B. In group A, K1 (flat keratometry) changed from 45.202 ± 3.782 D to 43.022 ± 3.819 D, indicating a flattening of −2.18 D, and K2 (steep keratometry) changed from 48.670 ± 4.066 D to 45.865 ± 4.794 D, indicating a flattening of −2.805 D. In group B, K1 (flat keratometry) changed from 46.213 ± 4.082 D to 43.190 ± 4.398 D, indicating a flattening of −3.023 D, and K2 (steep keratometry) changed from 50.774 ± 5.210 D to 46.380 ± 5.006 D, indicating a flattening of −4.394 D. For group A, the index of surface variance decreased to −5.07% and the index of height decentration to −26.81%. In group B, the index of surface variance decreased to −18.35% and the index of height decentration to −39.03%. These reductions indicate that the corneal surface became less irregular (index of surface variance) and the “cone” flatter and more central (index of height decentration) postoperatively. Conclusion Of the two sources of primary corneal data, the Scheimpflug rotating camera (Oculyzer™) for topography-guided normalization treatment with the WaveLight excimer laser platform appeared to provide more statistically significant improvement than the Placido disc topographer (Topolyzer™). Overall, the Athens protocol, aiming both to halt progression of keratoconic ectasia and to improve corneal topometry and visual performance, produced safe and satisfactory refractive, keratometric, and topometric results. The observed changes in visual acuity, along with keratometric flattening and topometric improvement, are suggestive of overall postoperative improvement.
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Affiliation(s)
- Anastasios John Kanellopoulos
- Laservision.gr Eye Institute, Athens, Greece ; New York University School of Medicine, Department of Opthalmology, NY, NY, USA
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Panos GD, Hafezi F, Gatzioufas Z. Pellucid marginal degeneration and keratoconus; differential diagnosis by corneal topography. J Cataract Refract Surg 2013; 39:968. [PMID: 23688900 DOI: 10.1016/j.jcrs.2013.04.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Indexed: 11/15/2022]
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Kanellopoulos AJ, Asimellis G. Introduction of quantitative and qualitative cornea optical coherence tomography findings induced by collagen cross-linking for keratoconus: a novel effect measurement benchmark. Clin Ophthalmol 2013; 7:329-35. [PMID: 23440024 PMCID: PMC3577010 DOI: 10.2147/opth.s40455] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose To introduce a novel, noninvasive technique to determine the depth and extent of anterior corneal stroma changes induced by collagen cross-linking (CXL) using quantitative analysis of high-resolution anterior-segment optical coherence tomography (OCT) post-operative images. Setting Private clinical ophthalmology practice. Patients and methods Two groups of corneal cross-sectional images obtained with the OptoVue RTVue anterior-segment OCT system were studied: group A (control) consisted of unoperated, healthy corneas, with the exception of possible refractive errors. The second group consisted of keratoconic corneas with CXL that were previously operated on. The two groups were investigated for possible quantitative evidence of changes induced by the CXL, and specifically, the depth, horizontal extent, as well as the cross-sectional area of intrastromal hyper-reflective areas (defined in our study as the area consisting of pixels with luminosity greater than the mean +2 × standard deviation of the entire stromal cross section) within the corneal stroma. Results In all images of the second group (keratoconus patients treated with CXL) there was evidence of intrastromal hyper-reflective areas. The hyper-reflective areas ranged from 0.2% to 8.8% of the cross-sectional area (mean ± standard deviation; 3.46% ± 1.92%). The extent of the horizontal hyper-reflective area ranged from 4.42% to 99.2% (56.2% ± 23.35%) of the cornea image, while the axial extent (the vertical extent in the image) ranged from 40.00% to 86.67% (70.98% ± 7.85%). There was significant statistical difference (P < 0.02) in these values compared to the control group, in which, by application of the same criteria, the same hyper-reflective area (owing to signal noise) ranged from 0.00% to 2.51% (0.74% ± 0.63%). Conclusion Herein, we introduce a novel, noninvasive, quantitative technique utilizing anterior segment OCT images to quantitatively assess the depth and cross-sectional area of CXL in the corneal stroma based on digital image analysis. Mean cross-sectional area showing evidence of CXL was 3.46% ± 1.92% of a 6 mm long segment.
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Affiliation(s)
- A John Kanellopoulos
- Laservision.gr Institute, Athens, Greece ; New York University Medical School, New York, NY, USA
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Yam JCS, Cheng ACK. Reduced cross-linking demarcation line depth at the peripheral cornea after corneal collagen cross-linking. J Refract Surg 2013; 29:49-53. [PMID: 23311741 DOI: 10.3928/1081597x-20121228-03] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 10/31/2012] [Indexed: 11/20/2022]
Abstract
PURPOSE To compare the corneal collagen cross-linking (CXL) demarcation line depth between the central and peripheral cornea after cross-linking using anterior segment optical coherence tomography. METHODS Retrospective interventional case series of 38 eyes with keratoconus or postoperative LASIK ectasia treated with riboflavin ultraviolet A CXL (UV-X, IROC). CXL demarcation line depth, corneal thickness, and the ratio of the CXL demarcation line depth to the corneal thickness were measured using anterior segment optical coherence tomography at the central cornea and at 2 and 4 mm from the corneal center in four regions: temporal, nasal, superior, and inferior. The CXL demarcation line depths at the center and periphery were compared using the Friedman test. RESULTS The CXL demarcation line was deepest in the central cornea (302 μm; range: 180 to 397 μm) and was reduced progressively toward the peripheral cornea, at nasal 2 mm (289.5 μm; range: 125 to 370 μm), at nasal 4 mm (206.5 μm; range: 100 to 307 μm), at temporal 2 mm (278.5 μm; range: 128 to 375 μm), and at temporal 4 mm (194 μm; range: 80 to 325 μm) (P<.001). The penetration proportion was greatest at the central cornea (64.8%; range: 44% to 80%) and was decreased toward the periphery, at nasal 2 mm (53.8%; range: 30% to 74%), at nasal 4 mm (33.8%; range: 19% to 53%), at temporal 2 mm (54.1%; range: 29% to 77%), and at temporal 4 mm (34.1%; range: 15% to 54%) (P⩽.001). CONCLUSIONS Both the CXL demarcation line depth and its proportion over the corneal thickness were greater at the central cornea than the peripheral cornea.
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Affiliation(s)
- Jason C S Yam
- Department of Opthalmology, Hong Kong Sanatorium and Hopsital, Hong Kong PR China
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Tummanapalli SS, Maseedupally V, Mandathara P, Rathi VM, Sangwan VS. Evaluation of corneal elevation and thickness indices in pellucid marginal degeneration and keratoconus. J Cataract Refract Surg 2012; 39:56-65. [PMID: 23107832 DOI: 10.1016/j.jcrs.2012.08.053] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 06/22/2012] [Accepted: 08/11/2012] [Indexed: 10/27/2022]
Abstract
PURPOSE To determine and compare corneal elevation and thickness indices, thereby formulating a reliable index to distinguish eyes with pellucid marginal degeneration (PMD) from keratoconus eyes and normal (control) eyes. SETTING LV Prasad Eye Institute, Hyderabad, India. DESIGN Initial model-building retrospective study. METHODS Anterior and posterior corneal elevations and thickness indices were obtained from the Orbscan IIz topographer. These values were analyzed and compared between PMD patients, keratoconus patients, and control subjects. RESULTS Of the indices, the mean values of anterior elevation (AE), ratio of the AE to the anterior best-fit sphere, ratio of the average power values of nasal quadrant to the average power values of inferior quadrant, and difference between maximum keratometry (K) and minimum K were significantly different between the 3 groups (P<.05). The highest area under the receiver-operating-characteristic (AROC) curve in discriminating PMD from keratoconus was for asphericity (0.974; cutoff ≥-0.07; sensitivity 93.3%; specificity 90.6%) followed by the ratio of average power values of the nasal and temporal quadrants to the average power values of the inferior and superior quadrants (Avg NT((D))/IS((D))) (0.959; cutoff ≥1.005; sensitivity 96.7%; specificity 90.6%). The PMD index (AROC curve, 0.935), with a cutoff of 3.45 or higher had 90% sensitivity and 93.7% specificity to distinguish PMD from keratoconus and had 100% sensitivity and 100% specificity to distinguish PMD from control eyes, with a cutoff of 2.46 or higher (AROC curve, 1.000). CONCLUSIONS The PMD index appeared to be highly sensitive and specific for diagnosing PMD. Asphericity and Avg NT((D))/IS((D)) were clinically relevant in discriminating PMD from other groups.
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Affiliation(s)
- Shyam Sunder Tummanapalli
- From the Cornea and Contact Lens Department (Tummanapalli, Mandathara, Rathi, Sangwan), LV Prasad Eye Institute, Hyderabad, India; the School of Optometry and Vision Science (Maseedupally), University of New South Wales, Sydney, Australia.
| | - Vinod Maseedupally
- From the Cornea and Contact Lens Department (Tummanapalli, Mandathara, Rathi, Sangwan), LV Prasad Eye Institute, Hyderabad, India; the School of Optometry and Vision Science (Maseedupally), University of New South Wales, Sydney, Australia
| | - Preeji Mandathara
- From the Cornea and Contact Lens Department (Tummanapalli, Mandathara, Rathi, Sangwan), LV Prasad Eye Institute, Hyderabad, India; the School of Optometry and Vision Science (Maseedupally), University of New South Wales, Sydney, Australia
| | - Varsha M Rathi
- From the Cornea and Contact Lens Department (Tummanapalli, Mandathara, Rathi, Sangwan), LV Prasad Eye Institute, Hyderabad, India; the School of Optometry and Vision Science (Maseedupally), University of New South Wales, Sydney, Australia
| | - Virender S Sangwan
- From the Cornea and Contact Lens Department (Tummanapalli, Mandathara, Rathi, Sangwan), LV Prasad Eye Institute, Hyderabad, India; the School of Optometry and Vision Science (Maseedupally), University of New South Wales, Sydney, Australia
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Current world literature. Curr Opin Ophthalmol 2012; 23:330-5. [PMID: 22673820 DOI: 10.1097/icu.0b013e32835584e4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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