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Patel SV, Hodge DO, Baratz KH. Corneal Backscatter, Pachymetric Indices, and Ectasia Indices for the Assessment of Fuchs Endothelial Corneal Dystrophy. Cornea 2024:00003226-990000000-00568. [PMID: 38830190 DOI: 10.1097/ico.0000000000003577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Accepted: 04/15/2024] [Indexed: 06/05/2024]
Abstract
PURPOSE To determine whether corneal backscatter, pachymetric indices, and ectasia indices derived from Scheimpflug tomography can identify Fuchs endothelial corneal dystrophy (FECD) corneas with abnormal tomography, the relationships between these parameters and tomographic edema in FECD, and if these parameters help predict improvement in central corneal thickness (CCT) after Descemet membrane endothelial keratoplasty (DMEK). METHODS Tomography maps of 132 eyes of 80 subjects with FECD were analyzed to determine how backscatter, pachymetric, and ectasia parameters compared with the instrument's normative database and if any predicted tomographic edema. Tomography maps from a separate group undergoing DMEK were split into derivation (48 eyes of 39 subjects) and validation (45 eyes of 41 subjects) subgroups to derive a predictive model of improvement in CCT after DMEK. Backscatter, pachymetric, and ectasia parameters were incorporated to determine if the model could be enhanced. RESULTS Among all ectasia, pachymetric, and backscatter parameters, at best only 65% of FECD corneas with definite tomographic edema could be identified based on the instrument's normative database. Among all parameters individually, the highest sensitivity for detecting tomographic edema was 77%. Anterior and mid-corneal backscatter featured in a model predicting improvement in CCT after DMEK with high performance in derivation (R2 = 0.79; 95% confidence interval, 0.65-0.87) and validation (R2 = 0.72; 95% confidence interval, 0.52-0.83) subgroups. CONCLUSIONS The Scheimpflug camera software program could not reliably detect abnormal tomography in FECD from corneal backscatter, pachymetric indices, or ectasia indices. Corneal backscatter contributes to, but does not enhance, a predictive model of improvement in CCT after DMEK.
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Affiliation(s)
- Sanjay V Patel
- Department of Ophthalmology, Mayo Clinic, Rochester, MN; and
| | - David O Hodge
- Department of Quantitative Health Sciences, Mayo Clinic, Jacksonville, FL
| | - Keith H Baratz
- Department of Ophthalmology, Mayo Clinic, Rochester, MN; and
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2
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Brandi-Dohrn F, Jiang J, Grewing V, Fritz M, Zander D, Lieberum JL, Kladny AM, Siegel H, Bixler S, Müller C, Reinhard T, Wacker K. Diurnal Variation of Visual Acuity and Refraction in Fuchs Endothelial Corneal Dystrophy. Cornea 2024; 43:83-87. [PMID: 37157119 DOI: 10.1097/ico.0000000000003291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 03/15/2023] [Indexed: 05/10/2023]
Abstract
PURPOSE Patients with advanced Fuchs endothelial corneal dystrophy frequently report poor vision in the morning, which improves as the day progresses. This study quantified the amount of variation in near and distance visual acuity and refraction over the course of a day. METHODS This was a prospective cohort study. Best-corrected distance visual acuity and near visual acuity were tested in participants with clinically advanced Fuchs dystrophy and in controls with healthy corneas. Subjective refraction and autorefraction were conducted in a presumed steady state in the afternoon. Measurements were repeated directly after eye opening in the hospital the next morning. In a subgroup, measurements were repeated every 30 minutes for up to 2 hours. RESULTS In Fuchs dystrophy, the mean distance visual acuity was worse by -3 letters (95% confidence interval, -4 to -1) directly after eye opening in the morning compared with late afternoon. No such difference was seen in healthy corneas. In Fuchs dystrophy, visual acuity improved over the course of the study. Visual acuity in the morning could be improved with fine tuning of refraction, and refractive changes were exclusive to Fuchs dystrophy (0.5-1.0 D in spherical equivalent in 30%, >1.0 D in 2% of eyes). CONCLUSIONS Distance and near visual acuity and refraction changes over the course of the day in patients with advanced Fuchs dystrophy. Although small changes in refraction may not usually require a second set of glasses for the first hours of the day, diurnal variation should be considered when determining disease severity in routine practice and in clinical trials.
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3
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Oie Y, Yamaguchi T, Nishida N, Okumura N, Maeno S, Kawasaki R, Jhanji V, Shimazaki J, Nishida K. Systematic Review of the Diagnostic Criteria and Severity Classification for Fuchs Endothelial Corneal Dystrophy. Cornea 2023; 42:1590-1600. [PMID: 37603692 DOI: 10.1097/ico.0000000000003343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 05/28/2023] [Indexed: 08/23/2023]
Abstract
PURPOSE There are no defined diagnostic criteria and severity classification for Fuchs endothelial corneal dystrophy (FECD), which are required for objective standardized assessments. Therefore, we performed a systematic literature review of the current diagnosis and severity classification of FECD. METHODS We searched the Ovid MEDLINE and Web of Science databases for studies published until January 13, 2021. We excluded review articles, conference abstracts, editorials, case reports with <5 patients, and letters. RESULTS Among 468 articles identified, we excluded 173 and 165 articles in the first and second screenings, respectively. Among the 130 included articles, 61 (47%) and 99 (76%) mentioned the diagnostic criteria for FECD and described its severity classification, respectively. Regarding diagnosis, slitlamp microscope alone was the most frequently used device in 31 (51%) of 61 articles. Regarding diagnostic findings, corneal guttae alone was the most common parameter [adopted in 23 articles (38%)]. Regarding severity classification, slitlamp microscopes were used in 88 articles (89%). The original or modified Krachmer grading scale was used in 77 articles (78%), followed by Adami's classification in six (6%). Specular microscopes or Scheimpflug tomography were used in four articles (4%) and anterior segment optical coherence tomography in one (1%). CONCLUSIONS FECD is globally diagnosed by the corneal guttae using slitlamp examination, and its severity is predominantly determined by the original or modified Krachmer grading scale. Objective severity grading using Scheimpflug or anterior segment optical coherence tomography can be applied in the future innovative therapies such as cell injection therapy or novel small molecules.
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Affiliation(s)
- Yoshinori Oie
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Takefumi Yamaguchi
- Department of Ophthalmology, Tokyo Dental College Ichikawa General Hospital, Ichikawa, Japan
| | - Nozomi Nishida
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Naoki Okumura
- Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan; and
| | - Sayo Maeno
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Ryo Kawasaki
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Vishal Jhanji
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Jun Shimazaki
- Department of Ophthalmology, Tokyo Dental College Ichikawa General Hospital, Ichikawa, Japan
| | - Kohji Nishida
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
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4
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Jones L, Efron N, Bandamwar K, Barnett M, Jacobs DS, Jalbert I, Pult H, Rhee MK, Sheardown H, Shovlin JP, Stahl U, Stanila A, Tan J, Tavazzi S, Ucakhan OO, Willcox MDP, Downie LE. TFOS Lifestyle: Impact of contact lenses on the ocular surface. Ocul Surf 2023; 29:175-219. [PMID: 37149139 DOI: 10.1016/j.jtos.2023.04.010] [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: 04/07/2023] [Accepted: 04/10/2023] [Indexed: 05/08/2023]
Abstract
Several lifestyle choices made by contact lens wearers can have adverse consequences on ocular health. These include being non-adherent to contact lens care, sleeping in lenses, ill-advised purchasing options, not seeing an eyecare professional for regular aftercare visits, wearing lenses when feeling unwell, wearing lenses too soon after various forms of ophthalmic surgery, and wearing lenses when engaged in risky behaviors (e.g., when using tobacco, alcohol or recreational drugs). Those with a pre-existing compromised ocular surface may find that contact lens wear exacerbates ocular disease morbidity. Conversely, contact lenses may have various therapeutic benefits. The coronavirus disease-2019 (COVID-19) pandemic impinged upon the lifestyle of contact lens wearers, introducing challenges such as mask-associated dry eye, contact lens discomfort with increased use of digital devices, inadvertent exposure to hand sanitizers, and reduced use of lenses. Wearing contact lenses in challenging environments, such as in the presence of dust and noxious chemicals, or where there is the possibility of ocular trauma (e.g., sport or working with tools) can be problematic, although in some instances lenses can be protective. Contact lenses can be worn for sport, theatre, at high altitude, driving at night, in the military and in space, and special considerations are required when prescribing in such situations to ensure successful outcomes. A systematic review and meta-analysis, incorporated within the review, identified that the influence of lifestyle factors on soft contact lens dropout remains poorly understood, and is an area in need of further research. Overall, this report investigated lifestyle-related choices made by clinicians and contact lens wearers and discovered that when appropriate lifestyle choices are made, contact lens wear can enhance the quality of life of wearers.
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Affiliation(s)
- Lyndon Jones
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada.
| | - Nathan Efron
- School of Optometry and Vision Science, Queensland University of Technology, Kelvin Grove, Queensland, Australia
| | - Kalika Bandamwar
- Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand
| | - Melissa Barnett
- University of California, Davis Eye Center, Sacramento, CA, USA
| | - Deborah S Jacobs
- Massachusetts Eye & Ear, Harvard Medical School, Boston, MA, USA
| | - Isabelle Jalbert
- School of Optometry and Vision Science, UNSW Sydney, NSW, Australia
| | - Heiko Pult
- Dr Heiko Pult Optometry & Vision Research, Weinheim, Germany
| | | | - Heather Sheardown
- Department of Chemical Engineering, McMaster University, Hamilton, Ontario, Canada
| | | | - Ulli Stahl
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada
| | | | - Jacqueline Tan
- School of Optometry and Vision Science, UNSW Sydney, NSW, Australia
| | - Silvia Tavazzi
- Department of Materials Science, University of Milano-Bicocca, Milan, Italy
| | | | - Mark D P Willcox
- School of Optometry and Vision Science, UNSW Sydney, NSW, Australia
| | - Laura E Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
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Loss of Corneal Nerves and Corneal Haze in Patients with Fuchs' Endothelial Corneal Dystrophy with the Transcription Factor 4 Gene Trinucleotide Repeat Expansion. OPHTHALMOLOGY SCIENCE 2022; 3:100214. [PMID: 36275201 PMCID: PMC9563205 DOI: 10.1016/j.xops.2022.100214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 07/30/2022] [Accepted: 08/19/2022] [Indexed: 11/22/2022]
Abstract
Objective Seventy percent of Fuchs' endothelial corneal dystrophy (FECD) cases are caused by an intronic trinucleotide repeat expansion in the transcription factor 4 gene (TCF4). The objective of this study was to characterize the corneal subbasal nerve plexus and corneal haze in patients with FECD with (RE+) and without the trinucleotide repeat expansion (RE-) and to assess the correlation of these parameters with disease severity. Design Cross-sectional, single-center study. Participants Fifty-two eyes of 29 subjects with a modified Krachmer grade of FECD severity from 1 to 6 were included in the study. Fifteen of the 29 subjects carried an expanded TCF4 allele length of ≥ 40 cytosine-thymine-guanine repeats (RE+). Main Outcomes Measures In vivo confocal microscopy assessments of corneal nerve fiber length (CNFL), corneal nerve branch density, corneal nerve fiber density (CNFD), and anterior corneal stromal backscatter (haze); Scheimpflug tomography densitometry measurements of haze in anterior, central, and posterior corneal layers. Results Using confocal microscopy, we detected a negative correlation between FECD severity and both CNFL and CNFD in the eyes of RE+ subjects (Spearman ρ = -0.45, P = 0.029 and ρ = -0.62, P = 0.0015, respectively) but not in the eyes of RE- subjects. Additionally, CNFD negatively correlated with the repeat length of the expanded allele in the RE+ subjects (Spearman ρ = -0.42, P = 0.038). We found a positive correlation between anterior stromal backscatter and severity in both the RE+ and RE- groups (ρ = 0.60, P = 0.0023 and ρ = 0.44, P = 0.024, respectively). The anterior, central, and posterior Scheimpflug densitometry measurements also positively correlated with severity in both the RE+ and RE- groups (P = 5.5 × 10-5, 2.5 × 10-4, and 2.9 × 10-4, respectively, after adjusting for the expansion status in a pooled analysis. However, for patients with severe FECD (Krachmer grades 5 and 6), the posterior densitometry measurements were higher in the RE+ group than in the RE- group (P < 0.05). Conclusions Loss of corneal nerves in FECD supports the classification of the TCF4 trinucleotide repeat expansion disorder as a neurodegenerative disease. Haze in the anterior, central, and posterior cornea correlate with severity, irrespective of the genotype. Quantitative assessments of corneal nerves and corneal haze may be useful to gauge and monitor FECD disease severity in RE+ patients.
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Zander DB, Jiang J, Reinhard T, Wacker K. Corneal Oedema: Aetiology, Diagnostic Testing, and Treatment. Klin Monbl Augenheilkd 2022; 239:752-759. [DOI: 10.1055/a-1759-3834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AbstractCorneal oedema results from an underlying pathology, which can be diverse in origin, and may be mechanical, dystrophic, or inflammatory, and affect any layer of the cornea. Diagnostic tools
such as Scheimpflug imaging and anterior segment optical coherence tomography have standardised quantification of corneal oedema and have become important aids in clinical practice. Timely
diagnosis and treatment are key to preventing irreversible damage to the corneal ultrastructure, such as anterior corneal fibrosis or endothelial cell damage. The oedema usually resolves
quickly when the underlying cause has been addressed. Symptomatic treatment using hyperosmolar agents has failed to show any benefits in oedema resolution or improvement in visual acuity
compared to placebo. In contrast, rho-associated protein kinase (ROCK) inhibitors offer a promising option for medical treatment in cases of endothelial dysfunction, but their safety and
efficacy must be further validated in large scale clinical trials. Until then, endothelial or penetrating keratoplasties remain the mainstay treatment where structural changes to the cornea
have occurred.
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Affiliation(s)
| | - Jana Jiang
- Eye Center, Medical Center – University of Freiburg, Freiburg, Germany
| | - Thomas Reinhard
- Eye Center, Medical Center – University of Freiburg, Freiburg, Germany
| | - Katrin Wacker
- Eye Center, Medical Center – University of Freiburg, Freiburg, Germany
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7
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Liu C, Gao ZQ, Li J, Zhou Q. Identification of novel therapeutic targets for Fuchs' endothelial corneal dystrophy based on gene bioinformatics analysis. PLoS One 2022; 17:e0264018. [PMID: 35239706 PMCID: PMC8893658 DOI: 10.1371/journal.pone.0264018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 01/31/2022] [Indexed: 11/19/2022] Open
Abstract
Fuchs' endothelial corneal dystrophy (FECD) is a disease where progressive visual impairment occurs by the thickening of the Descemet's membrane and the gradual degeneration and loss of corneal endothelial cells. This study aimed to investigate the key changes in gene expression associated with FECD and explore potential biomarkers and new therapeutic strategies for FECD. To explore the potential therapeutic targets of FECD, we downloaded the gene expression dataset GSE171830 from the Gene Expression Omnibus (GEO) database. A total of 303 differentially expressed genes (DEGs) were identified by the limma package. The enriched Gene Ontology (GO) annotations and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of DEGs mostly included the extracellular matrix organization, collagen-containing extracellular matrix, and the structural constituents of the extracellular matrix. Fifteen hub genes from the most significant module were ascertained by Cytoscape. Both collagen-containing extracellular matrix and extracellular matrix hit to ANXA1, VCAN, GPC3, TNC, IGFBP7, MATN3, and SPARCL1 genes in the GO cellular components. Among these genes, the expression of SPARCL1 was down-regulated in the FECD samples, whereas the expression of GPC3, MATN3, IGFBP7, TNC, VCAN, and ANXA1 was up-regulated in the FECD samples. Gene set enrichment analysis (GSEA) plots showed that among the 20,937 genes, SPARCL1 played an important role in three pathways, cytokine-cytokine receptor interaction, the TGF-beta signaling pathway, and antigen processing and presentation. The top three pathways enriched by the GPC3, MATN3, IGFBP7, TNC, VCAN, and ANXA1 genes were those for cytokine-cytokine receptor interaction, TGF-beta signaling, and RIG-I-like receptor signaling. In conclusion, the DEGs identified here might assist clinicians in understanding the pathogenesis of FECD. Furthermore, these identified biomarkers might serve as potential therapeutic targets for the treatment of FECD.
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Affiliation(s)
- Chao Liu
- Department of Ophthalmology, the First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui Province, China
| | - Zi-Qing Gao
- Department of Ophthalmology, the First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui Province, China
| | - Juan Li
- Department of Ophthalmology, the First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui Province, China
| | - Qi Zhou
- Department of Ophthalmology, the First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui Province, China
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8
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Patel SV. Imaging Fuchs Endothelial Corneal Dystrophy in Clinical Practice and Clinical Trials. Cornea 2021; 40:1505-1511. [PMID: 34074894 DOI: 10.1097/ico.0000000000002738] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/20/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT Corneal tomography has an emerging role in the assessment of Fuchs endothelial corneal dystrophy (FECD) in clinical practice and potentially for future clinical trials. Posterior elevation and pachymetry maps derived from elevation based Scheimpflug tomography can detect early corneal edema, even at a subclinical stage, enabling clinicians to better counsel patients about their vision and the risk of disease progression with and without cataract surgery. Tomographic imaging provides a functional assessment of corneal endothelial health, and could enable objective assessment of FECD progression, or regression, in response to novel therapeutic interventions. Clinicians and investigators should adopt Scheimpflug imaging for the assessment of FECD over traditional morphologic imaging modalities.
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Shahin A, Ramazani S.A A, Mehraji S, Eslami H. Synthesis and characterization of a chitosan/gelatin transparent film crosslinked with a combination of EDC/NHS for corneal epithelial cell culture scaffold with potential application in cornea implantation. INT J POLYM MATER PO 2021. [DOI: 10.1080/00914037.2020.1865349] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Ali Shahin
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, Iran
| | - Ahmad Ramazani S.A
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, Iran
| | - Sima Mehraji
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, Iran
| | - Hamed Eslami
- Department of Biomedical Engineering Biomaterial, Science and Research Branch, Islamic Azad University, Tehran, Iran
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10
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Eleiwa T, Elsawy A, Özcan E, Abou Shousha M. Automated diagnosis and staging of Fuchs' endothelial cell corneal dystrophy using deep learning. EYE AND VISION 2020; 7:44. [PMID: 32884962 PMCID: PMC7460770 DOI: 10.1186/s40662-020-00209-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 08/03/2020] [Indexed: 12/20/2022]
Abstract
Background To describe the diagnostic performance of a deep learning algorithm in discriminating early-stage Fuchs’ endothelial corneal dystrophy (FECD) without clinically evident corneal edema from healthy and late-stage FECD eyes using high-definition optical coherence tomography (HD-OCT). Methods In this observational case-control study, 104 eyes (53 FECD eyes and 51 healthy controls) received HD-OCT imaging (Envisu R2210, Bioptigen, Buffalo Grove, IL, USA) using a 6 mm radial scan pattern centered on the corneal vertex. FECD was clinically categorized into early (without corneal edema) and late-stage (with corneal edema). A total of 18,720 anterior segment optical coherence tomography (AS-OCT) images (9180 healthy; 5400 early-stage FECD; 4140 late-stage FECD) of 104 eyes (81 patients) were used to develop and validate a deep learning classification network to differentiate early-stage FECD eyes from healthy eyes and those with clinical edema. Using 5-fold cross-validation on the dataset containing 11,340 OCT images (63 eyes), the network was trained with 80% of these images (3420 healthy; 3060 early-stage FECD; 2700 late-stage FECD), then tested with 20% (720 healthy; 720 early-stage FECD; 720 late-stage FECD). Thereafter, a final model was trained with the entire dataset consisting the 11,340 images and validated with a remaining 7380 images of unseen AS-OCT scans of 41 eyes (5040 healthy; 1620 early-stage FECD 720 late-stage FECD). Visualization of learned features was done, and area under curve (AUC), specificity, and sensitivity of the prediction outputs for healthy, early and late-stage FECD were computed. Results The final model achieved an AUC of 0.997 ± 0.005 with 91% sensitivity and 97% specificity in detecting early-FECD; an AUC of 0.974 ± 0.005 with a specificity of 92% and a sensitivity up to 100% in detecting late-stage FECD; and an AUC of 0.998 ± 0.001 with a specificity 98% and a sensitivity of 99% in discriminating healthy corneas from all FECD. Conclusion Deep learning algorithm is an accurate autonomous novel diagnostic tool of FECD with very high sensitivity and specificity that can be used to grade FECD severity with high accuracy.
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Affiliation(s)
- Taher Eleiwa
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida 33136 USA.,Department of Ophthalmology, Faculty of Medicine, Benha University, Benha, Egypt
| | - Amr Elsawy
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida 33136 USA.,Electrical and Computer Engineering, University of Miami, Coral Gables, Florida USA
| | - Eyüp Özcan
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida 33136 USA.,Net Eye Medical Center, Gaziantep, Turkey
| | - Mohamed Abou Shousha
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida 33136 USA.,Electrical and Computer Engineering, University of Miami, Coral Gables, Florida USA.,Biomedical Engineering, University of Miami, Coral Gables, Florida USA
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11
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Patel SV, Hodge DO, Treichel EJ, Spiegel MR, Baratz KH. Repeatability of Scheimpflug Tomography for Assessing Fuchs Endothelial Corneal Dystrophy. Am J Ophthalmol 2020; 215:91-103. [PMID: 32112772 DOI: 10.1016/j.ajo.2020.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/31/2020] [Accepted: 02/01/2020] [Indexed: 12/22/2022]
Abstract
PURPOSE To determine if agreement between subjective interpretations of Scheimpflug tomography maps of corneas with Fuchs endothelial corneal dystrophy (FECD) is affected by daily and hourly changes in corneal edema. DESIGN Reliability analysis. METHODS Scheimpflug imaging pachymetry and posterior elevation maps of corneas with a range of severity of FECD were evaluated in a randomized manner for the presence of 3 tomographic features of edema. Agreement between interpretations of 1 masked observer was assessed (percentage, and κ-statistic with 95% confidence interval) for images taken within minutes on the same day, for images taken at a similar time on a different day, and for images taken over the course of a morning. Intra- and interobserver agreement was also assessed. RESULTS Interpretations for individual tomographic features agreed for ≥88% of images (κ ≥ 0.75) taken within minutes on the same day; complete disagreement (ie, disagreement for all 3 tomographic features in an image) occurred in ≤3% of images. Interpretations agreed for ≥77% of images (κ ≥ 0.52) taken at a similar time on a different day; complete disagreement did not occur. Interpretations agreed for ≥81% of images (κ ≥ 0.61) taken over the course of a morning; complete disagreement occurred in ≤6% of images. Intraobserver agreement was ≥93% (κ ≥ 0.83) and interobserver agreement was ≥93% (κ ≥ 0.66); complete disagreement did not occur. CONCLUSIONS Subjective interpretation of Scheimpflug images in FECD is highly repeatable for disease classification. Although small variations in interpretations resulted from pathophysiologic changes in corneal hydration and other factors, clinically significant disagreements in interpretation were uncommon and therefore unlikely to affect clinical decision-making.
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Affiliation(s)
- Sanjay V Patel
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, USA.
| | - David O Hodge
- Department of Health Sciences Research, Mayo Clinic, Jacksonville, Florida, USA
| | - Emily J Treichel
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, USA
| | - Matthew R Spiegel
- Department of Health Sciences Research, Mayo Clinic, Jacksonville, Florida, USA
| | - Keith H Baratz
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, USA
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12
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Matthaei M, Hribek A, Clahsen T, Bachmann B, Cursiefen C, Jun AS. Fuchs Endothelial Corneal Dystrophy: Clinical, Genetic, Pathophysiologic, and Therapeutic Aspects. Annu Rev Vis Sci 2020; 5:151-175. [PMID: 31525145 DOI: 10.1146/annurev-vision-091718-014852] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fuchs endothelial corneal dystrophy (FECD) is a bilateral corneal endothelial disorder and the most common cause of corneal transplantation worldwide. Professor Ernst Fuchs described the first 13 cases of FECD more than 100 years ago. Since then, we have seen far-reaching progress in its diagnosis and treatment. In the field of diagnostics, new technologies enable the development of more accurate classification systems and the more detailed breakdown of the genetic basis of FECD. Laboratory studies help in deciphering the molecular pathomechanisms. The development of minimally invasive surgical techniques leads to a continuous improvement of the postoperative result. This review highlights and discusses clinical, genetic, pathophysiologic, and therapeutic aspects of this common and important corneal disorder.
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Affiliation(s)
- Mario Matthaei
- Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany; , , , ,
| | - Agathe Hribek
- Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany; , , , ,
| | - Thomas Clahsen
- Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany; , , , ,
| | - Björn Bachmann
- Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany; , , , ,
| | - Claus Cursiefen
- Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany; , , , ,
| | - Albert S Jun
- Wilmer Eye Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA;
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13
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Loreck N, Adler W, Siebelmann S, Rokohl AC, Heindl LM, Cursiefen C, Bachmann BO, Matthaei M. Morning Myopic Shift and Glare in Advanced Fuchs Endothelial Corneal Dystrophy. Am J Ophthalmol 2020; 213:69-75. [PMID: 31954712 DOI: 10.1016/j.ajo.2020.01.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 10/25/2022]
Abstract
PURPOSE Impaired subjective morning visual acuity with improvement of symptoms during the day is pathognomonic for corneal endothelial dysfunction in advanced Fuchs endothelial corneal dystrophy (FECD). This study aimed to analyze the daily fluctuations of corneal thickness, refraction, and (glare) visual acuity in advanced FECD. DESIGN Prospective cohort study. METHODS Patients with advanced FECD (FECD group) and patients with normal cornea (control group) were enrolled. Routine clinical examination was performed using slit-lamp biomicroscopy, funduscopy, and macular optical coherence tomography. In addition, assessment using corneal Scheimpflug tomography (Pentacam), refraction, corrected distance visual acuity (CDVA), and glare CDVA was performed at 4 PM (afternoon) and the following day at 8 AM (morning). RESULTS A total of 29 FECD eyes and 22 control eyes were included. Diurnal variations from afternoon to morning were Δ corneal thickness (apex) ± standard deviation (SD) 41.45 ± 34.1 μm (P < .001, FECD group) and 5.5 ± 6.72 μm (P = .001, control group); Δ spherical equivalent ± SD -0.64 ± 0.6 diopters (D) (P < .001, FECD group) and -0.01 ± 0.50 D (P = .461, control group); Δ total corneal refractive power ± SD 0.60 ± 0.83 D (P = .001, FECD group) and -0.01 ± 0.49 D (P = .602, control group), Δ CDVA ± SD 0.15 ± 0.18 logarithm of minimal angle of resolution (logMAR) (P < .001, FECD group) and 0.02 ± 0.04 logMAR (P = .174, control group), Δ CDVA glare ± SD 0.34 ± 0.25 logMAR (P < .001, FECD group) and 0.05 ± 0.11 logMAR (P = .106, control group). CONCLUSION A morning myopic shift and increased glare paralleling increased corneal thickness may particularly contribute to subjective visual impairment in advanced FECD in the first hours after awaking. This should be taken into account during assessment and surgical decision-making in patients with FECD.
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Fritz M, Grewing V, Maier P, Lapp T, Böhringer D, Reinhard T, Wacker K. Diurnal Variation in Corneal Edema in Fuchs Endothelial Corneal Dystrophy. Am J Ophthalmol 2019; 207:351-355. [PMID: 31415734 DOI: 10.1016/j.ajo.2019.08.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 08/04/2019] [Accepted: 08/05/2019] [Indexed: 10/26/2022]
Abstract
PURPOSE The extent of diurnal variation in corneal edema in Fuchs dystrophy is unknown. We measured corneal thickness and posterior profile over the course of the day using Scheimpflug imaging. DESIGN Prospective cohort study. METHODS Participants with clinically advanced Fuchs dystrophy eyes undergoing endothelial keratoplasty and participants with healthy corneas were assessed around noon the day before surgery and late afternoon, in presumed steady state. After controlled overnight patching to standardize eyelid closure, participants were assessed immediately upon eye opening in hospital the morning of surgery. RESULTS Directly upon awakening, patients had mean corneal thickness of 663 μm (interquartile range [IQR], 625-707) in Fuchs dystrophy (n = 44) and controls (n = 11) had thickness of 557 μm (IQR, 527-601). In control corneas, there were no systematic changes with time. In Fuchs dystrophy eyes, corneal thickness decreased after awakening. Ninety-five percent of patients can be expected to have a decrease in corneal thickness over the first 4 hours after awakening between 31 μm and 58 μm (95% prediction interval). Posterior Q decreased on average by 0.15 (95% confidence interval [CI], 0.07-0.23) and posterior radius of curvature decreased by 0.20 mm (95% CI, 0.14-0.27) over the first 4 hours, indicating that edema resolution steepened the central posterior cornea. Beyond 4 hours after awakening, corneas no longer changed considerably in Fuchs dystrophy. CONCLUSION Impaired hydration control in clinically advanced Fuchs dystrophy makes measurements of key corneal parameters unreliable directly after eye opening. Beyond the first hours after eye opening, corneal thickness measurements are unlikely to vary more in Fuchs dystrophy eyes than in normal eyes.
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Patel SV, Hodge DO, Treichel EJ, Spiegel MR, Baratz KH. Predicting the Prognosis of Fuchs Endothelial Corneal Dystrophy by Using Scheimpflug Tomography. Ophthalmology 2019; 127:315-323. [PMID: 31685256 DOI: 10.1016/j.ophtha.2019.09.033] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/18/2019] [Accepted: 09/20/2019] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To determine if Scheimpflug tomography pachymetry map and posterior elevation map patterns, central corneal thickness (CCT), and corneal backscatter can predict the prognosis of Fuchs endothelial corneal dystrophy (FECD). DESIGN Cross-sectional study with follow-up of outcomes. PARTICIPANTS Ninety-six eyes (56 subjects) with a range of severity of FECD. METHODS Corneas were graded by cornea specialists according to the area and confluence of guttae and the presence of clinically definite edema. Masked and randomized Scheimpflug imaging pachymetry map and posterior elevation map patterns were assessed by 1 observer for loss of regular isopachs, displacement of the thinnest point of the cornea, and the presence of posterior surface depression. The prognosis of eyes over a 5-year (median) follow-up period was determined based on FECD progression (new onset of clinically definite edema or ≥5% increase in CCT) or intervention by endothelial keratoplasty. Cumulative probabilities of progression and intervention were estimated from survival analyses, with risk factors determined by using Cox proportional hazards models. MAIN OUTCOME MEASURES Pachymetry map and posterior elevation map patterns, corneal backscatter, and CCT (ultrasonic pachymetry). RESULTS In univariate analyses, loss of regular isopachs (hazard ratio [HR], 18.00) displacement of the thinnest point (HR, 11.53), focal posterior surface depression (HR, 10.21), and anterior corneal backscatter (HR, 1.22, per 1-grayscale unit increment), were risk factors for progression or intervention (P < 0.001), whereas CCT (HR, 1.30, per 25-μm increment) was not (P = 0.15). In multivariate analyses, loss of regular isopachs (HR, 11.57; P < 0.001) and displacement of the thinnest point (HR, 5.61; P = 0.02) were independent and clinically important risk factors for progression and intervention. The 5-year cumulative risk of disease progression and intervention was 7%, 48%, and 89% when none, 1 or 2, and all 3 pachymetry map and posterior elevation map parameters were present, respectively (P <0.001). The 4-year cumulative risk of disease progression and intervention after uncomplicated cataract surgery was 0%, 50%, and 75% when none, 1 or 2, and all 3 pachymetry map and posterior elevation map parameters were present, respectively (P < 0.001). CONCLUSIONS Three Scheimpflug tomography pachymetry map and posterior elevation map patterns can predict FECD prognosis independent of CCT. The risk of FECD progression and intervention, including after uncomplicated cataract surgery, increases according to the number of parameters present.
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Affiliation(s)
- Sanjay V Patel
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota.
| | - David O Hodge
- Department of Health Sciences Research, Mayo Clinic, Jacksonville, Florida
| | | | - Matthew R Spiegel
- Department of Health Sciences Research, Mayo Clinic, Jacksonville, Florida
| | - Keith H Baratz
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota
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Wacker K, Reinhard T, Maier P. [Pathogenesis and diagnostic evaluation of Fuchs' endothelial corneal dystrophy]. Ophthalmologe 2019; 116:221-227. [PMID: 30402742 DOI: 10.1007/s00347-018-0799-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Following new treatment options for Fuchs' endothelial corneal dystrophy, our understanding of optical and structural changes in the patient's cornea is also starting to improve. OBJECTIVE To provide an update on clinical evaluation of Fuchs' dystrophy. MATERIAL AND METHODS Standardized approaches to evaluate patients with Fuchs dystrophy in routine practice and research are discussed, accounting for the progressive and partially irreversible structural changes in all corneal layers. RESULTS Early structural changes in the cornea can be detected before clinical edema becomes visible on slit-lamp exam. Optical limitations resulting from these structural changes can be quantified not only with high-contrast acuity but also with glare or contrast sensitivity tests. Characteristic vision-related limitations of patients with Fuchs dystrophy can, e.g., be assessed with V-FUCHS, a Fuchs dystrophy-specific "Visual Function and Corneal Health Status" instrument for patient-reported outcomes. CONCLUSION Clinical grading of Fuchs dystrophy in an edematous and a non-edematous stage is outdated. Better therapy options and our improved understanding of progressive changes in the entire cornea require a standardized assessment of optical and structural changes and patient-reported limitations.
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Affiliation(s)
- K Wacker
- Klinik für Augenheilkunde, Universitätsklinikum Freiburg, Killianstr. 5, 79106, Freiburg, Deutschland.
| | - T Reinhard
- Klinik für Augenheilkunde, Universitätsklinikum Freiburg, Killianstr. 5, 79106, Freiburg, Deutschland
| | - P Maier
- Klinik für Augenheilkunde, Universitätsklinikum Freiburg, Killianstr. 5, 79106, Freiburg, Deutschland
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Patel SV. Towards Clinical Trials in Fuchs Endothelial Corneal Dystrophy: Classification and Outcome Measures-The Bowman Club Lecture 2019. BMJ Open Ophthalmol 2019; 4:e000321. [PMID: 31414054 PMCID: PMC6668606 DOI: 10.1136/bmjophth-2019-000321] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Accepted: 05/12/2019] [Indexed: 12/13/2022] Open
Abstract
The surgical treatment of Fuchs endothelial corneal dystrophy (FECD) has advanced dramatically over the last two decades. Penetrating keratoplasty has been superseded by various iterations of endothelial keratoplasty, and currently, surgical removal of host Descemet membrane without keratoplasty is being investigated. These surgical advances have been accompanied by significant improvement of our understanding of the underlying disease mechanisms, not least the discovery that FECD in western populations is predominantly an intronic trinucleotide repeat expansion disorder in the transcription factor 4 gene that results in RNA toxicity and mis-splicing. Understanding the disease mechanisms augurs well for developing targeted molecular medical therapies, which will require careful clinical investigation through trials to prove their efficacy and safety. As the field advances towards clinical trials, investigators should carefully define the disease state being treated and consider the options for outcome measures relevant to the type of intervention. FECD, and the outcomes of interventions to treat the disease, can be measured in terms of corneal morphology, corneal function and clinical impact. Standardising the approach for defining FECD and careful thought about the outcomes of intervention that are reported will help make the results of future trials for FECD applicable in clinical practice.
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Moezzi AM, Hutchings N, Fonn D, Simpson TL. Mixed Model Analysis of Between-Subject Variability in Overnight Corneal Swelling and Deswelling With Silicone Hydrogel Lenses. Invest Ophthalmol Vis Sci 2019; 59:2576-2585. [PMID: 29847665 DOI: 10.1167/iovs.17-23352] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To model between subject variability of corneal swelling (CS) and deswelling after overnight wear of silicone hydrogel (SiHy) contact lenses. Methods A total of 29 neophyte subjects wore 12 SiHy lenses with central transmissibility range of 31 to 211 Dk/t units on separate nights, in random order, and on one eye only. The contralateral eye served as the control. Central corneal thickness was measured using digital optical pachymetry before lens insertion, immediately after lens removal on waking, then 20, 40 minutes, 1, 2, and 3 hours later. Mixed modelling was conducted for simultaneous analysis of group and between-subject effects of CS and deswelling. Results The best model for overnight CS versus Dk/t was linear with a random intercept showing constant between-subject differences in CS for different Dk/t values. The best fit for corneal deswelling versus time was a curvilinear random intercept and random slope model. About 90% of the total between-subject deswelling variance in either lens or control eyes was due to the intercept variability with much less (∼10%) being due to the variability of the individual deswelling rate (slope). Subject age, sex, and ametropia were not predictors of individual corneal swelling in the swelling versus Dk/t analysis. Age, however, was a significant (inverse) predictor of the rate of corneal deswelling, only in lens-wearing eyes. Conclusions A large proportion of variability in corneal swelling is because of subject-specific differences in corneal response to hypoxia. This shows that "low swellers" and "high swellers" actually do exist.
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Affiliation(s)
- Amir M Moezzi
- Center for Ocular Research & Education (CORE, formerly Center for Contact Lens Research), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Natalie Hutchings
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Desmond Fonn
- Center for Ocular Research & Education (CORE, formerly Center for Contact Lens Research), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Trefford L Simpson
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
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Ahmed Mohamed ET, Perone JM, Brand S, Koegel M, Declercq NF. Scanning Acoustic Microscopy Comparison of Descemet's Membrane Normal Tissue and Tissue With Fuchs' Endothelial Dystrophy. Invest Ophthalmol Vis Sci 2018; 59:5627-5632. [PMID: 30481279 DOI: 10.1167/iovs.18-25516] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To describe the application of scanning acoustic microscopy in the GHz-range (GHz-SAM) for qualitative imaging and quantitative characterization of the micromechanical properties of the Descemet's membrane and endothelial cells of cornea tissue. Methods Investigated were samples of a normal tissue and a tissue with Fuchs' endothelial dystrophy (FECD, cornea Guttata). Descemet's membranes were fixed on glass substrates and imaged utilizing a focused acoustic lens operating at a center frequency of 1 GHz. Results GHz-SAM data, based on the well-established V(z) technique, revealed discrepancies in the velocity of the propagation of Rayleigh surface acoustic waves (RSAW). RSAW were found to be slower in glass substrates with FECD samples than in the same glass substrates (soda-lime) with normal Descemet membrane, which indicates lower shear and bulk moduli of elasticity in tissues affected by FECD. Conclusions Noninvasive/nondestructive GHz-SAM, is utilized in this study for the imaging and characterization of Descemet membranes, fixated on glass substrates. V(z) signatures containing sufficient oscillations were obtained for the system of Descemet membranes on glass substrates. The observed variation in the microelastic properties indicates potential for further investigations with GHz-SAM based on the V(z) technique.
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Affiliation(s)
- Esam T Ahmed Mohamed
- Laboratory for Ultrasonic Nondestructive Evaluation "LUNE", UMI Georgia Tech-CNRS 2958, Metz, France
| | - Jean-Marc Perone
- Ophthalmology Department of the Regional Hospital Center of Metz-Thionville, Mercy Hospital, Metz, France
| | - Sebastian Brand
- Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Center for Applied Microstructure Diagnostics CAM, Halle, Germany
| | - Michael Koegel
- Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Center for Applied Microstructure Diagnostics CAM, Halle, Germany
| | - Nico F Declercq
- Laboratory for Ultrasonic Nondestructive Evaluation "LUNE", UMI Georgia Tech-CNRS 2958, Metz, France
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Sun SY, Wacker K, Baratz KH, Patel SV. Determining Subclinical Edema in Fuchs Endothelial Corneal Dystrophy: Revised Classification using Scheimpflug Tomography for Preoperative Assessment. Ophthalmology 2018; 126:195-204. [PMID: 30153944 DOI: 10.1016/j.ophtha.2018.07.005] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 06/29/2018] [Accepted: 07/10/2018] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To determine if Scheimpflug tomography can identify subclinical corneal edema in Fuchs endothelial corneal dystrophy (FECD), and to recommend a new classification of FECD for clinical practice and research. DESIGN Cross-sectional study with follow-up of outcomes. PARTICIPANTS Ninety-three eyes from 57 subjects with a range of severity of FECD and 74 eyes from 40 subjects with normal corneas. METHODS Corneas were clinically assessed for FECD and corneal edema by using slit-lamp biomicroscopy, and categorized as having clinically definite edema (obvious visible edema), being suspicious for subclinical edema (possible corneal thickening without obvious edema on slit-lamp examination), or not having edema (no clinical suspicion of edema). Tomographic pachymetry and elevation maps derived from Scheimpflug images were evaluated by 3 masked observers for specific features believed to be consistent with corneal edema. FECD clinical disease course and outcomes were reviewed from the time of Scheimpflug image acquisition to the last available follow-up. MAIN OUTCOME MEASURES Presence of tomographic features: (1) loss of parallel isopachs, (2) displacement of the thinnest point of the cornea, and (3) focal posterior corneal surface depression. Clinical outcomes included the change in central corneal thickness (CCT) and vision after endothelial keratoplasty (EK). RESULTS The 3 specific tomographic features were all present in all FECD corneas with clinically definite edema (n = 15), in ≥81% of FECD corneas suspicious for subclinical edema (n = 16), in ≤42% of FECD corneas deemed not to have edema (n = 62), and in ≤5% of normal corneas (n = 74). Corneas suspicious for subclinical edema that subsequently underwent EK (n = 9) all had at least 2 of the tomographic features present before EK, and improvement in vision, CCT, and tomographic features after EK confirmed the presence of subclinical edema preoperatively. CONCLUSIONS Subclinical corneal edema in FECD can be detected by Scheimpflug tomography. We recommend classifying FECD corneas as having clinically definite edema (based on slit-lamp examination), subclinical edema (based on tomographic features without clinically definite edema), or no edema (no tomographic or slit-lamp features of edema). This classification is independent of CCT and should be considered when evaluating FECD eyes for cataract surgery or EK.
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Affiliation(s)
- Susan Y Sun
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota
| | - Katrin Wacker
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota; Eye Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Keith H Baratz
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota
| | - Sanjay V Patel
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota.
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Abstract
PURPOSE OF REVIEW Assessment of corneal biomechanics has been an unmet clinical need in ophthalmology for many years. Many researchers and clinicians have identified corneal biomechanics as source of variability in refractive procedures and one of the main factors in keratoconus. However, it has been difficult to accurately characterize corneal biomechanics in patients. The recent development of Brillouin light scattering microscopy heightens the promise of bringing biomechanics into the clinic. The aim of this review is to overview the progress and discuss prospective applications of this new technology. RECENT FINDINGS Brillouin microscopy uses a low-power near-infrared laser beam to determine longitudinal modulus or mechanical compressibility of tissue by analyzing the return signal spectrum. Human clinical studies have demonstrated significant difference in the elastic properties of normal corneas versus corneas diagnosed with mild and severe keratoconus. Clinical data have also shown biomechanical changes after corneal cross-linking treatment of keratoconus patients. Brillouin measurements of the crystalline lens and sclera have also been demonstrated. SUMMARY Brillouin microscopy is a promising technology under commercial development at present. The technique enables physicians to characterize the biomechanical properties of ocular tissues.
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Affiliation(s)
- Seok Hyun Yun
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital
| | - Dimitri Chernyak
- Intelon Optics Inc., Zero Emerson Place, Boston Massachusetts, USA
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Abstract
PURPOSE Patients with Fuchs endothelial corneal dystrophy (FECD) often notice poor vision in the morning that improves as the day progresses. In this study, we determined changes in corneal optical properties associated with induced corneal edema. METHODS Twenty-three phakic eyes (23 participants) with FECD (grades 1-6, modified Krachmer scale) and 8 normal eyes (8 participants) were examined by Scheimpflug photography. Central corneal thickness, high-order aberrations from anterior and posterior corneal surfaces, and backscatter from the anterior, mid-, and posterior cornea were determined from the Scheimpflug images. A low-oxygen permeable contact lens was placed on the eye, and eyes were closed for 2 hours, after which the lens was removed and Scheimpflug photography was repeated for up to 5 hours to determine changes in backscatter and high-order aberrations. RESULTS Corneas swelled by 10% [95% confidence interval (CI), 9-10]. Backscatter from the anterior cornea increased by 416 scatter units (SU, 95% CI, 344-488; P < 0.001), independent of the presence and severity of FECD. Recovery of anterior backscatter was slower in advanced FECD (81 SU/h, 95% CI, 60-120) compared with normal (123 SU/h, 95% CI, 95-150; P = 0.019). Anterior and posterior corneal high-order aberrations, and mid and posterior backscatter, did not increase with induced swelling. CONCLUSIONS Inducing corneal edema increases anterior corneal backscatter but not high-order aberrations. Subjective poor vision in the morning in FECD is probably caused by scattered light rather than by high-order aberrations, suggesting that these patients experience more disability glare than decreased visual acuity.
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Lawman S, Madden PW, Romano V, Dong Y, Mason S, Williams BM, Kaye SB, Willoughby CE, Harding SP, Shen YC, Zheng Y. Deformation velocity imaging using optical coherence tomography and its applications to the cornea. BIOMEDICAL OPTICS EXPRESS 2017; 8:5579-5593. [PMID: 29296489 PMCID: PMC5745104 DOI: 10.1364/boe.8.005579] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/06/2017] [Accepted: 10/09/2017] [Indexed: 05/07/2023]
Abstract
Optical coherence tomography (OCT) can monitor human donor corneas non-invasively during the de-swelling process following storage for corneal transplantation, but currently only resultant thickness as a function of time is extracted. To visualize and quantify the mechanism of de-swelling, we present a method exploiting the nanometer sensitivity of the Fourier phase in OCT data to image deformation velocities. The technique was demonstrated by non-invasively showing during de-swelling that osmotic flow through an intact epithelium is negligible and removing the endothelium approximately doubled the initial flow at that interface. The increased functional data further enabled the validation of a mathematical model of the cornea. Included is an efficient method of measuring high temporal resolution (1 minute demonstrated) corneal thickness, using automated collection and semi-automated graph search segmentation. These methods expand OCT capabilities to measure volume change processes for tissues and materials.
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Affiliation(s)
- Samuel Lawman
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
| | - Peter W. Madden
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
| | - Vito Romano
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
- St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool L7 8XP, UK
| | - Yue Dong
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - Sharon Mason
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
| | - Bryan M. Williams
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
| | - Stephen B. Kaye
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
- St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool L7 8XP, UK
| | - Colin E. Willoughby
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
- St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool L7 8XP, UK
| | - Simon P. Harding
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
- St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool L7 8XP, UK
| | - Yao-Chun Shen
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - Yalin Zheng
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
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