Evaluation of Visual Quality in Patients With Fuchs Endothelial Corneal Dystrophy

Differences in Guttae Ultramorphology in Relation to Visual Function in Fuchs Endothelial Corneal Dystrophy

PURPOSE

The purpose of this study was to investigate the differences in guttae ultramorphology and their relation to visual function in eyes with Fuchs endothelial corneal dystrophy (FECD).

METHODS

Thirty FECD eyes without ocular comorbidities were included. Visual functional parameters (best-corrected visual acuity with high-contrast and low-contrast letters and contrast sensitivity/LogCS) and corneal morphology measured with Scheimpflug tomography (Pentacam) were assessed. The surgically removed Descemet membranes were examined by light and transmission electron microscopy.

RESULTS

Preoperative mean best-corrected visual acuity (logarithm of the minimum angle of resolution) was 0.52 ± 0.18, LogCS 0.96 ± 0.21 and central corneal thickness 640 ± 55 μm. All eyes had signs of subclinical corneal edema in Scheimpflug tomography; clinically visible corneal edema was present in 40% of eyes. Histological findings included a posterior fibrillar zone (PFZ) in 10 specimens (33%) and abnormal collagen depositions in Descemet membranes in 14 specimens (47%). Guttae buried within the PFZ were present only in eyes with clinically visible edema (n = 4, 13%). There was no difference in visual function results and tomography parameters between eyes with and without PFZ or between protruding guttae and guttae embedded in a PFZ, respectively.

CONCLUSIONS

Guttae morphology and density were not correlated with visual functional parameters. Guttae buried in a PFZ occurred only in eyes with clinically manifest edema, and thereby, they are an ultramorphological sign for advanced FECD. Subclinical edema was present in all eyes and might be more relevant for quality of vision than guttae ultramorphology.

Change in Visual Acuity of Patients With Fuchs Endothelial Corneal Dystrophy Over 1 Year

PURPOSE

To determine whether the clinical and paraclinical course of Fuchs endothelial corneal dystrophy (FECD) over 1 year is related to the extent of triplet repetition in the transcription factor 4 (TCF4) gene.

METHODS

A prospective study with a 1-year follow-up was conducted. A total of 104 patients (160 eyes) with FECD and an equivalent number of age- and sex-matched control subjects without FECD were included. At inclusion, the corneas were graded using the modified Krachmer grade (KG) and patients were genotyped for the number of trinucleotide repeats (TNRs) in the TCF4 gene by the short tandem repeat assay. Visual acuity, Scheimpflug tomographic features, and the Visual Function and Corneal Health Status using a visual disability instrument were measured on 2 visits at 1-year intervals.

RESULTS

KGs ranged from 1 to 6, and 46% of eyes had grades 1 to 4. 71% of the patients harbored TNR expansion (>40) versus 13% in control subjects ( P < 0.001). Severity at inclusion was higher in the presence of TNR expansion when considering eyes independently (mean grade ±SD, 4.08 ± 1.42) without TNR expansion and 4.66 ± 1.27 with TNR expansion ( P = 0.024). In 1 year, the ETDRS score significantly decreased by -2.97 (95% confidence interval -4.69 to -1.26, P = 0.001) and the ETDRS score with glare by -4.25 (95% confidence interval -6.22 to -2.27, P < 10 -5 ). There was no relationship between the rate of decline and TNR expansion or KG. Central corneal thickness and Visual Function and Corneal Health Status scores did not significantly vary.

CONCLUSIONS

It is possible to measure a subtle progression of FECD over a period as short as 1 year. We did not find a relationship between the presence of TNR expansion and the speed of deterioration over 1 year. This work should facilitate the design of future clinical trials on FECD.

Influence of Subclinical Corneal Edema on Contrast Sensitivity in Fuchs Endothelial Corneal Dystrophy

PURPOSE

The aim of this study was to compare visual function, with a focus on contrast sensitivity, between patients with Fuchs endothelial corneal dystrophy (FECD) with and without subclinical corneal edema.

METHODS

In this cross-sectional, observational, single-center study, 46 pseudophakic eyes of 31 patients with FECD were divided into 2 groups depending on the presence of subclinical corneal edema. All eyes presented with a Krachmer grade of 5 and no clinical corneal edema. The criteria for subclinical corneal edema were loss of regular isopachs, displacement of the thinnest point, and focal posterior surface depression in Scheimpflug tomography. If more than 1 criterion was present, subclinical corneal edema was diagnosed. The corrected distance visual acuity, contrast sensitivity (Pelli-Robson chart and CSV-1000 test with optional glare), and straylight were measured. The differences between both groups were analyzed using clustered Wilcoxon rank-sum tests.

RESULTS

The corrected distance visual acuity and the contrast sensitivity, measured with a Pelli-Robson chart, were significantly inferior in eyes with subclinical corneal edema compared with eyes without subclinical edema ( P < 0.05). At all spatial frequencies, eyes with subclinical edema demonstrated lower contrast sensitivity with a statistically significantly reduction in total contrast sensitivity when tested with ( P = 0.005) and without ( P = 0.002) glare. The straylight did not significantly differ between both groups ( P > 0.05).

CONCLUSIONS

The corrected distance visual acuity and contrast sensitivity were significantly reduced in FECD eyes with subclinical corneal edema compared with those with no subclinical edema. This decrease in visual quality may be considered when evaluating the need for surgical intervention at earlier stages of FECD.

Descemet Membrane Endothelial Keratoplasty (DMEK) for Severe Verrucous Posterior Polymorphous Corneal Dystrophy with Uncommon Clinical and Ultrastructural Findings

PURPOSE

To report a case of severe verrucous posterior polymorphous corneal dystrophy (PPCD) and cataract, which was treated with Descemet membrane endothelial keratoplasty (DMEK) and simultaneous cataract surgery as a triple procedure (Triple-DMEK).

METHODS

A 62-year-old female patient presented to our department for co-evaluation of advanced PPCD with cataract and progressive light sensitivity in both eyes. The clinical examination demonstrated unusual clinical findings with prominent verrucous lesions on the posterior surface of the cornea without corneal decompensation. We performed a Triple-DMEK in case of simultaneous cataract. The corneal tissue was examined by light and transmission electron microscopy.

RESULTS

Intraoperatively, it was difficult to remove the verrucous structures completely after classical descemetorhexis. Light microscopic examination demonstrated epithelium-like transformation of the corneal endothelium by immunostaining (cytokeratin AE1/3 staining). Transmission electron microscopy revealed thickening of Descemet's membrane (18.5 to 30.0 µm). The anterior banded layer had a normal structure and was slightly thickened (3.5 to 5.5 µm). A normal posterior non-banded layer (PNBL) was observed but thinned (2.5 to 4.0 µm) or missing. It was followed by an altered PNBL with abnormal fibrillary inclusions, which was strongly and variably thickened (11.0 to 24.5 µm). The corneal endothelium was degenerated, partially absent, and epithelial-like altered. The nodular lesions were found to consist of a few degenerated cells that were embedded in an amorphous extracellular matrix interspersed with collagen fibers, which were not arranged in regular lamellae, forming the corneal stroma. The occurrence of pigment granules among the cellular debris suggested that the cells were endothelial cells. The corrected distance visual acuity improved from 20/50 to 20/30 in the right eye (+ 0.00/- 1.75/157°) and from 20/60 to 20/30 in the left eye (+ 0.00/- 1.75/33°), with significant improvement in light sensitivity.

CONCLUSION

The clinical and ultrastructural findings seem to be an unusual variant of the typical characteristic appearance of a PPCD. This case demonstrates that Triple-DMEK is feasible even in very advanced dystrophic changes of the posterior corneal surface, with good morphological and functional results.

Hepatocyte Growth Factor Modulates Corneal Endothelial Wound Healing In Vitro

In this study, we assessed the impact of hepatocyte growth factor (HGF) on corneal endothelial cells (CECs), finding that HGF concentrations of 100-250 ng/mL significantly increased CEC proliferation by 30%, migration by 32% and improved survival under oxidative stress by 28% compared to untreated controls (p < 0.05). The primary objective was to identify non-fibrotic pharmacological strategies to enhance corneal endothelial regeneration, addressing a critical need in conditions like Fuchs' endothelial dystrophy (FED), where donor tissue is scarce. To confirm the endothelial nature of the cultured CECs, Na+/K+-ATPase immunohistochemistry was performed. Proliferation rates were determined through BrdU incorporation assays, while cell migration was assessed via scratch assays. Cell viability was evaluated under normal and oxidative stress conditions using WST-1 assays. To ensure that HGF treatment did not trigger epithelial-mesenchymal transition, which could lead to undesirable fibrotic changes, α-SMA staining was conducted. These comprehensive methodologies provided robust data on the effects of HGF, confirming its potential as a therapeutic agent for corneal endothelial repair without inducing harmful EMT, as indicated by the absence of α-SMA expression. These findings suggest that HGF holds therapeutic promise for enhancing corneal endothelial repair, warranting further investigation in in vivo models to confirm its clinical applicability.

Corneal Endothelial Morphology and Ocular Biometric Indexes in Premature Children With and Without Retinopathy of Prematurity

Purpose

The purpose of this study was to analyze human corneal endothelial cells (HCECs) morphology and ocular biometrics in premature (PM) children with or without retinopathy of prematurity (ROP).

Methods

Retrospective data on patient demographics, HCECs status, and ocular biometrics with at least 2 visits between 2016 and 2021 were reviewed. The main outcomes were endothelial cell density (ECD), coefficient of variation (CV), hexagonal cell ratio (HEX), central corneal thickness (CCT), axial length, anterior chamber depth, keratometry, corneal diameter, pupil diameter, and refraction status. Generalized estimating equation was used to evaluate the differences between PM no-ROP and ROP groups. We also analyzed the trend of ECD, CV, HEX, and CCT change with age between groups.

Results

The study included 173 PM patients without ROP and 139 patients with ROP. A total of 666 and 544 measurements were recorded in the PM no-ROP and ROP groups, respectively. The ROP group had higher spherical power, myopic spherical equivalent (SE), and steeper steep keratometry (K; P < 0.05). The ROP group had higher CV (P = 0.0144), lower HEX (P = 0.0012) and thicker CCT (P = 0.0035). In the HCECs parameters, the ROP group had slower ECD decrement (P < 0.0001), faster CV decrement (P = 0.0060), and faster HEX increment (P = 0.0001). A difference in corneal morphology changes between the ROP and PM no-ROP groups were prominent in patients with lower gestational age (GA) in the subgroup analysis.

Conclusions

Worse HCECs morphology and higher myopic status were initially observed in patients with prior ROP but not in PM patients with no-ROP. ECD and HCECs morphology improved with age, especially in patients with low GA.

Applications of Imaging Technologies in Fuchs Endothelial Corneal Dystrophy: A Narrative Literature Review

Fuchs endothelial corneal dystrophy (FECD) is a complex genetic disorder characterized by the slow and progressive degeneration of corneal endothelial cells. Thus, it may result in corneal endothelial decompensation and irreversible corneal edema. Moreover, FECD is associated with alterations in all corneal layers, such as thickening of the Descemet membrane, stromal scarring, subepithelial fibrosis, and the formation of epithelial bullae. Hence, anterior segment imaging devices that enable precise measurement of functional and anatomical changes in the cornea are essential for the management of FECD. In this review, the authors will introduce studies on the application of various imaging modalities, such as anterior segment optical coherence tomography, Scheimpflug corneal tomography, specular microscopy, in vitro confocal microscopy, and retroillumination photography, in the diagnosis and monitoring of FECD and discuss the results of these studies. The application of novel technologies, including image processing technology and artificial intelligence, that are expected to further enhance the accuracy, precision, and speed of the imaging technologies will also be discussed.

Fuchs endothelial corneal dystrophy: an updated review

PURPOSE

The present review will summarize FECD-associated genes and pathophysiology, diagnosis, current  therapeutic approaches, and future treatment perspectives.

METHODS

Literature review.

RESULTS

Fuchs' endothelial corneal dystrophy (FECD) is the most common bilateral corneal dystrophy and accounts for one-third of all corneal transplants performed in the US. FECD is caused by a combination of genetic and non-heritable factors, and there are two types: early-onset FECD, which affects individuals from an early age and is usually more severe, and late-onset FECD, which is more common and typically manifests around the age of 40. The hallmark findings of FECD include progressive loss of corneal endothelial cells and the formation of focal excrescences (guttae) on the Descemet membrane. These pathophysiological changes result in progressive endothelial dysfunction, leading to a decrease in visual acuity and blindness in later stages. The present review will summarize FECD-associated genes and pathophysiology, diagnosis, current therapeutic approaches, and future treatment perspectives.

CONCLUSION

With the characterization and understanding of FECD-related genes and ongoing research into regenerative therapies for corneal endothelium, we can hope to see more significant improvements in the future in the management and care of the disease.

Translation and validation of the Visual Function and Corneal Health Status (V-FUCHS) questionnaire into Spanish language

PURPOSE

To translate and validate the V-FUCHS questionnaire into Spanish in a population of patients with Fuchs endothelial dystrophy (DEF).

METHODS

The V-FUCHS consists of 15 short, easily understandable questions that assess visual aspects of quality of life in patients with DEF, which can be gathered into a group of seven that assess the "Visual Difficulty" factor and another group of eight that assess the "Glare Factor". For the translation and cultural adaptation, the standardized norms for this process were followed, among other phases, a translation, a back-translation and an application in patients with DEF.

RESULTS

In the first phase, consensus was reached on the Spanish translation of the V-FUCHS. Subsequently, 25 patients were included to carry out the pre-test phase with the aim of assessing the applicability and feasibility of the test. The score obtained a minimum value of -0.88 and a maximum value of +2.44, according to the Rasch probabilistic scale. The mean value obtained from the Visual Difficulty factor was 0.61 (±0.71), while the mean for the Glare Factor was 0.41 (±0.51).

CONCLUSION

The validation of the V-FUCHS questionnaire, after its translation and adaptation into Spanish, proved to be a useful tool for assessing the visual quality of patients with DEF. Patients with a more advanced stage of the disease presented a greater severity in the test result. Likewise, the Glare Factor (Glare) correlates better with the pachymetric increase than with the visual acuity of the patient.

Visual Function in Pseudophakic Eyes with Fuchs' Endothelial Corneal Dystrophy

PURPOSE

To assess vision in pseudophakic eyes with Fuchs' endothelial corneal dystrophy (FECD) before the onset of clinically detectable corneal edema.

DESIGN

Cross-sectional study.

METHODS

Sixty-one otherwise healthy pseudophakic eyes of 38 subjects with FECD (without clinically detectable edema) and 17 otherwise healthy pseudophakic eyes of 9 subjects with normal corneas. Subjects underwent clinical examination to determine the morphologic distribution of guttae (severity grading). Standardized best-corrected high-contract and low-contrast (photopic and mesopic) visual acuity (HCVA, LCVA) and straylight were measured. Scheimpflug tomography posterior elevation and pachymetry maps were interpreted for 3 tomographic features of subclinical edema: loss of regular isopachs, displacement of the thinnest point of the cornea, and presence of posterior surface depression.

RESULTS

In FECD without tomographic features of edema (ie, normal tomography patterns), HCVA, LCVA, and straylight did not differ from that of eyes with normal corneas (P ≥ .09); these eyes encompassed the full range of severity grading of guttae. In FECD with all 3 tomographic features of edema, the same parameters were worse compared with eyes with normal corneas (P ≤ .02). In FECD with 1 or 2 tomographic abnormalities, mesopic LCVA (P = .04) and straylight (P = .003) were worse compared with eyes with normal corneas.

CONCLUSIONS

Impairment of vision was associated with the presence of tomographic edema in eyes with FECD. When tomography patterns were normal in FECD (ie, guttae were present without tomographic edema), visual acuity and straylight were normal, and therefore corneal surgical intervention would not typically be indicated to improve vision.

U-Net Convolutional Neural Network for Segmenting the Corneal Endothelium in a Mouse Model of Fuchs Endothelial Corneal Dystrophy

PURPOSE

The purpose of this study was to assess the U-Net-based convolutional neural network performance for segmenting corneal endothelium and guttae of Fuchs endothelial corneal dystrophy.

METHODS

Twenty-eight images of corneal endothelial cells and guttae of Col8a2L450W/L450W knock-in mice were obtained by specular microscopy. We used 20 images as training data to develop the U-Net for analyzing guttae and cell borders. The proposed network was validated using independent test data of 8 images. Cell density, hexagonality, and coefficient of variation were calculated from the predicted cell borders and compared with ground truth.

RESULTS

U-Net allowed the prediction of cell borders and guttae, and overlays of those segmentations on specular microscopy images highly corresponded to ground truth. The average number of guttae per field was 6.25 ± 8.07 for ground truth and 6.25 ± 7.87 when predicted by the network (Pearson correlation coefficient 0.989, P = 3.25 × 10 -6 ). The guttae areas were 1.60% ± 1.79% by manual determination and 1.90% ± 2.02% determined by the network (Pearson correlation coefficient 0.970, P = 6.72 × 10 -5 ). Cell density, hexagonality, and coefficient of variation analyzed by the proposed network for cell borders showed very strong correlations with ground truth (Pearson correlation coefficient 0.989, P = 3.23 × 10 -6 , Pearson correlation coefficient 0.978, P = 2.66 × 10 -5 , and Pearson correlation coefficient 0.936, P = 6.20 × 10 -4 , respectively).

CONCLUSIONS

We demonstrated proof of concept for application of U-Net for objective analysis of corneal endothelial cells and guttae in Fuchs endothelial corneal dystrophy, based on limited ground truth data.

Contrast Sensitivity Changes after Phototherapeutic Keratectomy in Heterozygote Granular Corneal Dystrophy Type 2

Purpose: Contrast sensitivity, the ability to distinguish the relative difference in luminance of an object from its surrounding or adjacent objects, is a useful measure of visual function. In granular corneal dystrophy type 2 (GCD2), opacity of the corneal stroma causes deterioration in visual function. We compared the contrast sensitivity of GCD2 patients before and after phototherapeutic keratectomy (PTK) to evaluate the perioperative visual function in these patients.Methods: This study included 22 eyes of heterozygote GCD2 patients. The visual acuity and contrast sensitivity were measured before and after PTK. The contrast sensitivity was measured in mesopic and photopic background luminances, with glare (G) levels of 0-2 (G0, G1, and G2, respectively) and spatial frequencies at 1.5, 3, 6, 12, and 18 cycles per degree (cpd).Results: The contrast sensitivity increased after PTK at 1.5 and 3 cpd in mesopic and photopic conditions with G0-2 glare (p < 0.05). At 6 cpd, the contrast sensitivity increased in the mesopic condition with G1 glare, and in the photopic condition with G0-2 glare (p < 0.05). However, there was no change in contrast sensitivity at any glare level at 12 and 18 cpd after PTK.Conclusions: In GCD2 patients, the contrast sensitivity increased significantly after PTK. The vision of GCD2 patients, which is decreased due to corneal opacity, is improved after PTK.

Prevalence and severity of cornea guttata in the graft following Descemet Membrane Endothelial Keratoplasty (DMEK)

PURPOSE

The aim of this study was to determine the prevalence and severity of cornea guttata (CG) in grafts after Descemet membrane endothelial keratoplasty (DMEK) and to investigate its impact on various clinical parameters during follow-up.

METHODS

This retrospective study included 664 operations (DMEK and triple-DMEK) on 466 patients. The prevalence and progression of CG after the operation were examined using endothelial specular microscopy images. The severity grade of CG was classified into four grades: G0 without CG, G1 - G3 with increasing severity of CG. Clinical parameters such as central corneal thickness (CCT), visual acuity (VA), endothelial cell density (ECD), pleomorphism and polymegalism were examined during a postoperative follow-up time of 19.6 ± 15.8 months.

RESULTS

Cornea guttata (CG) appeared postoperatively in 124 (18.7%) eyes. 112 (16.9%) could be classified as G1, 9 (1.4%) as G2 and only 3 (0.5%) as G3. The examination of clinical parameters showed significant differences between healthy and low-grade CG (G0/G1) and high-grade CG (G2/G3). A significant deterioration was found in the corrected distance visual acuity (CDVA) (p = 0.02). CCT showed an increase between G0 (534 ± 58 μm) and G2 (549 ± 71 μm)/G3 (558 ± 56 μm) with a p-value of 0.02. Additionally, a significant increase in pleomorphism (p = 0.003) and polymegalism (p = 0.04) was detected.

CONCLUSION

Cornea guttata (CG) prevalence after DMEK and triple-DMEK was found to be 18.7%, although most of these cases were classified as low-grade CG and showed no clinical significance. Around 1.9% were classified as high-grade CG and significantly affected several clinical parameters during the follow-up.

Descemet membrane endothelial keratoplasty (DMEK) improves vision-related quality of life

Purpose

To evaluate vision-related quality of life (VRQL) before and after Descemet membrane endothelial keratoplasty (DMEK).

Methods

The study was conducted in patients with Fuchs endothelial dystrophy or pseudophakic bullous keratopathy undergoing DMEK alone or in combination with cataract surgery (triple-DMEK) between August 2019 and March 2020 at the University of Leipzig Medical Center. Best-corrected visual acuity (BCVA) was measured. Visual acuity factor (VAF) and glare factor (GF) scores were calculated using the Visual Function and Corneal Health Status Instrument questionnaire answered by patients before surgery and 6 months thereafter. Subgroup analyses were performed for DMEK versus triple-DMEK, and for first versus second eyes, in addition to correlation analyses of scores with preoperative BCVA.

Results

Forty-six patients were included in this analysis. VAF score improved from 0.68 ± 0.54 to 0.02 ± 0.57 (P < 0.0001) and GF score improved from 0.53 ± 0.43 to -0.11 ± 0.39 (P < 0.0001) during follow-up. Both scores improved without significant differences after surgery in the first and in the fellow eye (P < 0.0001) and after DMEK and triple-DMEK (P < 0.0001). The improvement of scores did not correlate with preoperative BCVA (r = 0.06, P = 0.68 for VAF; r =  -0.09, P = 0.54 for GF).

Conclusion

VRQL improves similarly after DMEK and triple-DMEK and between first and second operated eye. The extent of improvement is independent of the preoperative BCVA. The results of this study can be useful when planning DMEK by enabling a prediction of anticipated VRQL gain.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00417-022-05711-9.

Cataract surgery in patients with Fuchs' dystrophy and corneal decompensation indicated for Descemet's membrane endothelial keratoplasty

The availability of corneal donor tissue is limited in most developing countries. This study evaluated whether patients with coexisting cataract and Fuchs’ dystrophy with corneal decompensation awaiting Descemet’s membrane endothelial keratoplasty (DMEK) benefited from phacoemulsification. This is a retrospective case–control study which included patients with Fuchs’ dystrophy and evidence of corneal decompensation awaiting DMEK. Best-corrected visual acuity (BCVA) and central corneal thickness (CCT) were documented at baseline (pre-cataract surgery in the case group, or at the time of transplantation registry in the control group), 1-month and pre-DMEK. A total of 16 phakic patients with visually significant cataracts had cataract surgery during the study period, and 15 pseudophakic patients were included as controls. There was no significant difference with regard to BCVA at baseline, 1-month or pre-DMEK between the case and control groups. Similarly, no significant difference in CCT was found at baseline, 1-month or pre-DMEK. In the case group, 4 patients with improved visual acuity post-cataract surgery chose to defer DMEK. After stratification, statistical analysis showed significantly better BCVA in the deferred group (n = 4) at 1-month post-cataract surgery, compared to the DMEK group (n = 12) (0.21 ± 0.21 vs. 0.86 ± 0.29 LogMAR, P = 0.004). The other parameters, including baseline BCVA and CCT at any time point documented, were not statistically different. In conclusion, in patients with Fuchs’ dystrophy and decompensated corneas awaiting transplantation, phacoemulsification did not lead to significant increase of corneal thickness nor deterioration of visual acuity. A few patients achieved satisfactory vision after cataract surgery and deferred endothelial keratoplasty.

Corneal Densitometry and In Vivo Confocal Microscopy in Patients with Monoclonal Gammopathy—Analysis of 130 Eyes of 65 Subjects

Background: Corneal imaging may support an early diagnosis of monoclonal gammopathy. The goal of our study was to analyze corneal stromal properties using Pentacam and in vivo confocal cornea microscopy (IVCM) in subjects with monoclonal gammopathy. Patients and methods: In our cross-sectional study, patients with monoclonal gammopathy (130 eyes of 65 patients (40.0% males; age 67.65 ± 9.74 years)) and randomly selected individuals of the same age group, without hematological disease (100 eyes of 50 control subjects (40.0% males; age 60.67 ± 15.06 years)) were included. Using Pentacam (Pentacam HR; Oculus GmbH, Wetzlar, Germany), corneal stromal light scattering values were obtained (1) centrally 0–2 mm zone; (2) 2–6 mm zone; (3) 6–10 mm zone; (4) 10–12 mm zone. Using IVCM with Heidelberg Retina Tomograph with Rostock Cornea Module (Heidelberg Engineering, Heidelberg, Germany), the density of hyperreflective keratocytes and the number of hyperreflective spikes per image were manually analyzed, in the stroma. Results: In the first, second and third annular zone, light scattering was significantly higher in subjects with monoclonal gammopathy, than in controls (p ≤ 0.04). The number of hyperreflective keratocytes and hyperreflective spikes per image was significantly higher in stroma of subjects with monoclonal gammopathy (p ≤ 0.012). Conclusions: Our study confirms that increased corneal light scattering in the central 10 mm annular zone and increased keratocyte hyperreflectivity may give rise to suspicion of monoclonal gammopathy. As corneal light scattering is not increased at the limbal 10–12 mm annular zone in monoclonal gammopathy subjects, our spatial analysis provides evidence against the limbal origin of corneal paraprotein deposition. Using IVCM, stromal hyperreflective spikes may represent specific signs of monoclonal gammopathy.

The corneal endothelium: clinical review of endothelial cell health and function

The endothelial cell is a critical structure within the cornea and is responsible for maintaining corneal clarity through its pump function. Endothelial cells are lost over time naturally but can be injured medically, surgically, or as a part of various dystrophies. Monitoring of endothelial cells can be performed clinically or more formally with specular microscopy. In cases of significant compromise, endothelial cells can be transplanted by various endothelial keratoplasty techniques. The future pipeline is bright for possible endothelial cell regeneration and rehabilitation. This article reviews these topics in depth to provide a comprehensive look at the structure and function of the endothelial cell, etiologies of endothelial cell damage, detailed review of iatrogenic causes of endothelial cell loss, and management strategies.

Evaluation of corneal safety in systemic lupus erythematosus patients undergoing long-term hydroxychloroquine treatment

PURPOSE

The aim of this study was to examine the effects of long-term use of hydroxychloroquine (HQ) on the pachymetric, aberrometric, and densitometric values of the cornea and corneal endothelium in lupus patients.

METHOD

Twenty-two eyes (study group) of 22 patients using HQ for treatment of lupus and 25 eyes (control group) of 25 healthy individuals were included in this prospective study. A specular microscopy was used to measure corneal endothelial cell density (ECD), percentage of hexagonal cells (HEX%), coefficient of variation of the cell size (CV). Then, a Pentacam® HR corneal tomography system was used to measure central corneal thickness (CCT), corneal aberrometry values in 6-mm pupil diameters and corneal densitometry values in 6-mm corneal zones (0-2 mm and 2-6 mm).

RESULTS

While ECD was significantly lower in the study group than in the control group (p = 0.034), CCT was significantly higher in the study group (p = 0.032). The higher-order aberrations values and the anterior corneal densitometry values in the 0-2 mm and 2-6 mm corneal zones in the study group were found to be significantly higher than the control group (p = 0.021, p = 0.007 and p = 0.013).

CONCLUSION

Prolonged use of HQ may cause some changes in the cornea. In the follow-up of these cases, detailed examination of the cornea as well as the macula may be important for the protection of corneal health.

Update on the Surgical Management of Fuchs Endothelial Corneal Dystrophy

Fuchs endothelial corneal dystrophy (FECD) is the most common posterior corneal dystrophy and the leading indication for corneal transplantation in the United States. FECD is slowly progressive, and patients develop gradual corneal endothelial decompensation, eventually resulting in failure of the endothelium to maintain corneal deturgescence. Medical management consists of topical hyperosmotic agents to facilitate dehydration of the cornea, but surgical intervention is often required to regain corneal clarity. The surgical management of FECD has evolved over the past two decades as corneal transplantation techniques have allowed for more selective keratoplasty and replacement of only the diseased layers of the cornea. Prior surgical management consisted of penetrating keratoplasty (PK) that carried significant intraoperative risks associated with "open sky" as well as postoperative risks of graft rejection, wound dehiscence, postoperative astigmatism, and prolonged visual rehabilitation. In the past 15 years, endothelial keratoplasty (EK) has become the treatment of choice for endothelial disease, significantly reducing the risks associated with the surgical treatment of FECD. Here we discuss the current surgical management of FECD, including the introduction of Descemet stripping only (DSO), and highlight future investigative efforts.

Association of the Gutta-Induced Microenvironment With Corneal Endothelial Cell Behavior and Demise in Fuchs Endothelial Corneal Dystrophy

Importance

The number and size of guttae increase over time in Fuchs endothelial corneal dystrophy (FECD); however, the association between these physical parameters and disease pathogenesis is unclear.

Objective

To determine the role of guttae in corneal endothelial cell function.

Design, Settings, and Participants

In an in vitro model, cells from a human corneal endothelial cell line, HCENC-21T, were seeded on decellularized normal (n = 30) and FECD (n = 70) endothelial basement (Descemet) membranes (DMs). Normal human corneas were sent to our laboratory from 3 sources. The study took place at the Schepens Eye Research Institute, Massachusetts Eye and Ear, Boston, and was performed from September 2015 to July 2017. Normal DMs were obtained from 3 different tissue banks and FECD-DMs were obtained from patients undergoing endothelial keratoplasty in 2 departments.

Main Outcomes and Measures

Endothelial cell shape, growth, and migration were assessed by live-cell imaging, and gene expression analysis as a function of guttae diameter was assessed by laser capture microscopy.

Results

Mean (SD) age of normal-DMs donors was 65.6 (4.4) years (16 women [53%]), and mean (SD) age of FECD-DMs donors was 68.9 (10.6) years (43 women [61%]). Cells covered a greater area (mean [SD], 97.7% [8.5%]) with a greater mean (SD) number of cells (2083 [153] cells/mm2) on the normal DMs compared with the FECD DMs (72.8% [11%]; P = .02 and 1541 [221] cells/mm2 221/mm2; P = .01, respectively). Differences in endothelial cell growth over guttae were observed on FECD DMs depending on the guttae diameter. Guttae with a mean (SD) diameter of 10.5 (2.9) μm did not impede cell growth, whereas those with a diameter of 21.1 (4.9) μm were covered only by the cell cytoplasm. Guttae with the largest mean (SD) diameter, 31.8 (3.8) μm, were not covered by cells, which instead surrounded them in a rosette pattern. Moreover, cells adjacent to large guttae upregulated αSMA, N-cadherin, Snail1, and NOX4 genes compared with ones grown on normal DMs or small guttae. Furthermore, large guttae induced TUNEL-positive apoptosis in a rosette pattern, similar to ex vivo FECD specimens.

Conclusions and Relevance

These findings highlight the important role of guttae in endothelial cell growth, migration, and survival. These data suggest that cell therapy procedures in FECD might be guided by the diameter of the host guttae if subsequent clinical studies confirm these laboratory findings.

Descemet membrane endothelial keratoplasty (DMEK): an update on safety, efficacy and patient selection

Descemet membrane endothelial keratoplasty (DMEK) is gaining popularity worldwide as a procedure to address corneal endothelial dysfunctions. Its perfect anatomical result improves outcomes and expedites visual recovery. This review addresses important aspects of safety, efficacy and patient selection.

Lithium chloride (LiCl) induced autophagy and downregulated expression of transforming growth factor β-induced protein (TGFBI) in granular corneal dystrophy

This study evaluated whether lithium chloride (LiCl) prevents cytoplasmic accumulation of mutant-transforming growth factor β-induced protein (Mut-TGFBI) in granular corneal dystrophy (GCD) via activation of the autophagy pathway. Levels of TGFBI and microtubule-associated protein 1A/1B-light chain 3 (LC3) in 3 GCD patients and healthy controls were analyzed by immunohistochemistry (IHC) staining and Western blot. Primary corneal fibroblasts were isolated and transfected with wild type or mutant type TGFBI over-expressed vectors, and then treated with LiCl and/or autophagy inhibitor 3-methyladenine (3-MA). Then, levels of TGFBI, glycogen synthase kinase-3 (GSK-3) and LC3-I/-II were detected. Cell viability and transmission electron microscopy assay were also performed. Levels of TGFBI and LC3 were significantly increased in GCD patients. Over-expression of mutant type TGFBI inhibited cell viability and induced autophagy in corneal fibroblasts. LiCl downregulated the expression of TGFBI in mutant type TGFBI over-expressed cells in a dose- and time-dependent manner. LiCl enhanced autophagy in mutant type TGFBI over-expressed cells and recovered cell viability in those cells. However, the effects of LiCl were partly attenuated when autophagy was suppressed by 3-MA. To summarize, treatment with LiCl inhibited the expression of TGFBI and recovery the inhibitory of mutant type TGFBI in cell viability, at least part through enhancing of autophagy. These data strongly suggest that LiCl may be useful in the treatment of GCD.