Dysregulation of DNA repair genes in Fuchs endothelial corneal dystrophy.

Fuchs Endothelial Corneal Dystrophy (FECD), a late-onset oxidative stress disorder, is the most common cause of corneal endothelial degeneration and is genetically associated with CTG repeat expansion in Transcription Factor 4 (TCF4). We previously reported accumulation of nuclear (nDNA) and mitochondrial (mtDNA) damage in FECD. Specifically, mtDNA damage was a prominent finding in development of disease in the ultraviolet-A (UVA) induced FECD mouse model. We hypothesize that an aberrant DNA repair may contribute to the increased DNA damage seen in FECD. We analyzed differential expression profiles of 84 DNA repair genes by real-time PCR arrays using Human DNA Repair RT-Profiler plates using cDNA extracted from Descemet's membrane-corneal endothelium (DM-CE) obtained from FECD patients with expanded (>40) or non-expanded (<40) intronic CTG repeats in TCF4 gene and from age-matched normal donors. Change in mRNA expression of <0.5- or >2.0-fold in FECD relative to normal was set as cutoff for down- or upregulation. Downregulated mitochondrial genes were further validated using the UVA-based mouse model of FECD. FECD specimens exhibited downregulation of 9 genes and upregulation of 8 genes belonging to the four major DNA repair pathways, namely, base excision repair (BER), nucleotide excision repair (NER), mismatch repair (MMR), and double strand break (DSB) repair, compared to normal donors. MMR gene MSH2 and BER gene POLB were preferentially upregulated in expanded FECD. BER genes LIG3 and NEIL2, DSB repair genes PARP3 and TOP3A, NER gene XPC, and unclassified pathway gene TREX1, were downregulated in both expanded and non-expanded FECD. MtDNA repair genes, Lig3, Neil2, and Top3a, were also downregulated in the UVA-based mouse model of FECD. Our findings identify impaired DNA repair pathways that may play an important role in DNA damage due to oxidative stress as well as genetic predisposition noted in FECD.

Activation of PINK1-Parkin-Mediated Mitophagy Degrades Mitochondrial Quality Control Proteins in Fuchs Endothelial Corneal Dystrophy.

Corneal endothelium (CE) is a monolayer of mitochondria-rich cells, critical for maintaining corneal transparency compatible with clear vision. Fuchs endothelial corneal dystrophy (FECD) is a heterogeneous, genetically complex disorder, where oxidative stress plays a key role in the rosette formation during the degenerative loss of CE. Increased mitochondrial fragmentation along with excessive mitophagy activation has been detected in FECD; however, the mechanism of aberrant mitochondrial dynamics in CE cell loss is poorly understood. Here, the role of oxidative stress in mitophagy activation in FECD is investigated. Immunoblotting of FECD ex vivo specimens revealed an accumulation of PINK1 and phospho-Parkin (Ser65) along with loss of total Parkin and total Drp1. Similarly, modeling of rosette formation with menadione (MN), led to phospho-Parkin accumulation in fragmented mitochondria resulting in mitophagy-induced mitochondrial clearance, albeit possibly in a PINK1-independent manner. Loss of PINK1, phospho-Drp1, and total Drp1 was prominent after MN-induced oxidative stress, but not after mitochondrial depolarization by carbonyl cyanide m-chlorophenyl hydrazone. Moreover, MN-induced mitophagy led to degradation of Parkin along with sequestration of Drp1 and PINK1 that was rescued by mitophagy inhibition. This study shows that in FECD, intracellular oxidative stress induces Parkin-mediated mitochondrial fragmentation where endogenous Drp1 and PINK1 are sequestered and degraded by mitophagy during degenerative loss of post-mitotic cells of ocular tissue.

Prospective Randomized Trial of Corneal Cross-linking Riboflavin Dosing Frequencies for Treatment of Keratoconus and Corneal Ectasia.

PURPOSE: To investigate whether the riboflavin dosing frequency affects corneal cross-linking efficacy or safety, given that isotonic riboflavin solution is viscous and each installation coats the corneal surface with a film that absorbs some of the incident ultraviolet A light. DESIGN: Prospective, randomized, single-center equivalence trial. PARTICIPANTS: Patients with progressive keratoconus or ectasia after refractive surgery (n = 510). METHODS: One eye per patient was prospectively randomized to 2-minute or 5-minute riboflavin dosing intervals with standard corneal cross-linking (epithelial removal and 30-minute irradiation with 3 mW/cm2 ultraviolet A light). Block randomization resulted in comparable representation of keratoconus and ectasia after refractive surgery in the 2 treatment arms. Treatment equivalence was assessed using the 2 one-sided test. Fellow eyes (n = 207) were treated with 5-minute dosing and considered in the safety analysis. MAIN OUTCOME MEASURES: The primary hypothesis was equivalent change in the topography-derived maximum keratometry value from baseline to 6 months with 2-minute vs. 5-minute dosing. A ±0.75-diopter margin of equivalence for the treatment difference between dosing regimens was considered clinically relevant. Adverse events and changes from baseline to 6 months in corrected distance visual acuity (CDVA), uncorrected distance visual acuity, and minimum corneal thickness were assessed. RESULTS: The mean reduction in maximum keratometry from baseline was equivalent with 2-minute and 5-minute riboflavin dosing intervals at 6 months (0.97 and 0.76 diopters, respectively; 90% confidence interval for treatment difference, -0.23 to 0.66; per-protocol population). With both dosing intervals, the mean improvement in CDVA was 0.07 logarithm of the minimum angle of resolution or 3.5 letters at 6 months. Of the 635 study and fellow eyes examined at 6 months, 134 (21%) gained and 32 (5%) lost 2 or more lines of CDVA. Three eyes (0.4%) developed sterile infiltrates, 1 (0.1%) had delayed epithelial healing with dendrites, and 3 (0.4%) had recurrent epithelial defects. Three eyes (0.4%) were re-treated. CONCLUSIONS: The 2 riboflavin dosing regimens produced equivalent reduction in the maximum keratometry value, with a favorable safety profile.

Five-Year Graft Survival of Descemet Membrane Endothelial Keratoplasty (EK) versus Descemet Stripping EK and the Effect of Donor Sex Matching.

PURPOSE: To determine whether the reduced risk of immunologic rejection with Descemet membrane endothelial keratoplasty (DMEK) results in a 5-year survival advantage relative to Descemet stripping endothelial keratoplasty (DSEK) and to determine whether matching the donor and recipient sex affects the rejection episode and graft survival rates. DESIGN: Retrospective cohort study. PARTICIPANTS: Patients with Fuchs' endothelial corneal dystrophy treated with DSEK or DMEK. METHODS: This study reviewed 2017 consecutive cases (1312 DSEK and 705 DMEK) performed by 13 surgeons between 2003 and 2012 and included the surgeons' first cases. Survival rates were calculated by Kaplan-Meier analysis. MAIN OUTCOME MEASURES: Immunologic rejection episodes, graft failure or replacement for any reason, and endothelial cell loss. RESULTS: The 5-year rejection episode rate was lower with DMEK (2.6% vs. 7.9% with DSEK, relative risk, 0.29; 95% confidence interval, 0.16-0.53) despite early reduction of topical corticosteroids in 25% of the DMEK cases. African Americans (n = 46) had a higher risk of rejection episodes than other races (relative risk, 4.4; 95% confidence interval, 2.0-9.6). The cumulative 5-year survival rate was 93% with DSEK and DMEK (P = 0.86). Forty-four DMEK and 69 DSEK grafts failed or were replaced within 5 years, but only 1 DMEK and 4 DSEK failures followed a rejection episode. Rejection episodes increased endothelial cell loss (P = 0.004) but were not a significant risk factor for graft failure within 5 years (P = 0.90). The mean 5-year endothelial cell loss was similar between DMEK (48%±19%) and DSEK (47%±19%) (P = 0.22). Graft rejection episode and survival rates were not significantly influenced by whether the sex of the donor matched that of the recipient (rejection episodes: P = 0.07 for female recipients and P = 0.33 for male recipients; graft survival: P = 0.67 for female recipients and P = 0.17 for male recipients). CONCLUSIONS: Five-year graft survival was similar between DMEK and DSEK. Although DMEK had a significantly lower risk of immunologic rejection, rejection episodes rarely resulted in graft failure within 5 years with either procedure. Sex matching the donor and recipient provided no survival advantage with DSEK or DMEK.

Existence of Neural Crest-Derived Progenitor Cells in Normal and Fuchs Endothelial Dystrophy Corneal Endothelium.

Human corneal endothelial cells are derived from neural crest and because of postmitotic arrest lack competence to repair cell loss from trauma, aging, and degenerative disorders such as Fuchs endothelial corneal dystrophy (FECD). Herein, we identified a rapidly proliferating subpopulation of cells from the corneal endothelium of adult normal and FECD donors that exhibited features of neural crest-derived progenitor (NCDP) cells by showing absence of senescence with passaging, propensity to form spheres, and increased colony forming efficacy compared with the primary cells. The collective expression of stem cell-related genes SOX2, OCT4, LGR5, TP63 (p63), as well as neural crest marker genes PSIP1 (p75(NTR)), PAX3, SOX9, AP2B1 (AP-2ß), and NES, generated a phenotypic footprint of endothelial NCDPs. NCDPs displayed multipotency by differentiating into microtubule-associated protein 2, ß-III tubulin, and glial fibrillary acidic protein positive neurons and into p75(NTR)-positive human corneal endothelial cells that exhibited transendothelial resistance of functional endothelium. In conclusion, we found that mitotically incompetent ocular tissue cells contain adult NCDPs that exhibit a profile of transcription factors regulating multipotency and neural crest progenitor characteristics. Identification of normal NCDPs in FECD-affected endothelium holds promise for potential autologous cell therapies.

Descemet's Membrane Endothelial Keratoplasty: Risk of Immunologic Rejection Episodes after Discontinuing Topical Corticosteroids.

PURPOSE: To assess the risk of immunologic rejection episodes if topical corticosteroids are discontinued 1 year after Descemet's membrane endothelial keratoplasty (DMEK) compared with continued once-per-day use. DESIGN: Prospective, longitudinal, parallel-group study. PARTICIPANTS: A total of 400 eyes of 259 DMEK recipients, aged 23 to 90 years. METHODS: Patients were enrolled 1 year after DMEK and allowed to choose whether to stop or continue once-daily topical corticosteroids to maximize compliance. Fellow eyes were eligible for enrollment because the donor grafts were independent. Participants were examined at 1, 3, 6, and 12 months during the second year after DMEK. Results were assessed using Kaplan-Meier survival analysis. MAIN OUTCOME MEASURES: Incidence of immunologic rejection episodes. RESULTS: Steroids were discontinued in 277 eyes (no steroid group) and continued once per day in 123 eyes (steroid group). The subject demographics were well balanced across groups; 99% of the subjects were white, and 95% of the grafts were performed to treat Fuchs' dystrophy. The cumulative incidence of rejection episodes was significantly greater in the no steroid group (6% vs. 0% in the steroid group; P = 0.013). Thirteen of 14 rejection episodes (all in the no steroid group) resolved with resumption of topical corticosteroids. Overall, 1 of 277 grafts (0.4%) failed in the no steroid group, and none failed in the steroid group during the second year after DMEK (P = 0.49). The endothelial cell loss between 1 and 2 years was comparable in the no steroid and steroid groups (6.4%±12% vs. 5.6%±14%, respectively; P = 0.67). CONCLUSIONS: Continued once-per-day use of a topical corticosteroid, even a weak one, was protective against rejection episodes during the second year after DMEK, whereas 6% experienced a rejection episode when steroids were discontinued. Among the 364 eyes that completed 12 months' follow-up, only 1 graft (0.27%) failed.

Descemet Stripping Endothelial Keratoplasty: Ten-Year Endothelial Cell Loss Compared with Penetrating Keratoplasty.

PURPOSE: To assess endothelial cell density (ECD) and model 10-year cell loss after Descemet stripping endothelial keratoplasty (DSEK), and to compare with results after penetrating keratoplasty (PK) performed for the same indications in the Cornea Donor Study (CDS). DESIGN: Retrospective, longitudinal study. PARTICIPANTS: Five hundred ninety DSEK recipients, 21 to 96 years of age, treated for Fuchs' dystrophy (n = 498; 84%), pseudophakic or aphakic corneal edema (n = 89; 15%), or other endothelial dysfunction (n = 3; <1%). METHODS: Review of 1005 consecutive primary DSEK procedures by 6 surgeons identified 752 grafts (75%) in 590 recipients with ECD measurements at 1 or more postoperative examinations between 6 months and 10 years. Four statistical models applied previously to the CDS PK data were considered. The preferred model (Bayesian Markov chain Monte Carlo) accounted for missing data, selective dropout from graft failure, correlations between fellow eyes, and correlations between longitudinal repeated measures. MAIN OUTCOME MEASURES: Central corneal ECD. RESULTS: The median donor corneal ECD (25th-75th percentiles) was 3005 cells/mm(2) (2852-3203 cells/mm(2)) at baseline, 2077 cells/mm(2) (1660-2411 cells/mm(2)) at 6 months, and 926 cells/mm(2) (617-1433 cells/mm(2)), with a range from 408 to 2538 cells/mm(2) at 10 years. After median cell loss of 32% in the perioperative period, ECD declined at a linear rate of approximately 110 cells/mm(2) per year between 6 months and 10 years after DSEK. At 10 years, the median cell loss was 71% (53%-80%) relative to the baseline donor ECD, comparable with the 76% (70%-82%) median cell loss after PK by 68 surgeons in the CDS. The 10-year ECD correlated with the 6-month postoperative ECD (r = 0.56; P < 0.001), but not with the baseline donor ECD (r = -0.04; P = 0.78). Selective dropout from graft failure did not affect the cell loss model significantly. CONCLUSIONS: The linear decline in ECD after DSEK was consistent with shorter-term endothelial keratoplasty studies and was distinct from the biexponential cell loss trend characteristic of PK. By 10 years, cell loss was comparable in surviving clear grafts for both DSEK and PK.

Three-Year Longitudinal Survey Comparing Visual Satisfaction with LASIK and Contact Lenses.

PURPOSE: To assess patient satisfaction and perceived outcomes with different methods of refractive error correction through annual surveys administered over a 3-year period. DESIGN: Prospective, longitudinal, parallel-group, multicenter survey. PARTICIPANTS: A total of 1800 subjects, aged 18 to 60 years, who had LASIK or continued using contact lenses. METHODS: Twenty sites across the United States enrolled subjects who completed a study-specific baseline survey during a contact lens examination or while being evaluated as a candidate for LASIK. Links to follow-up surveys were emailed annually for 3 years. Between-group differences were assessed by analysis of variance, and associations were assessed by logistic multivariate regression. MAIN OUTCOME MEASURES: Visual satisfaction. RESULTS: Of 1800 subjects, 694 (39%) comprised the control group who continued contact lens wear, 819 (45%) wore contacts at baseline and had LASIK, and 287 (16%) wore glasses at baseline and had LASIK. Most contact lens users had worn them successfully ≥5 years. The proportion expressing strong satisfaction with their current vision correction method decreased from 63% at baseline to 54% at year 3 in the contact lens control group, whereas 88% of former contact lens wearers and 77% of former glasses wearers were strongly satisfied with LASIK at year 3. Patients 40 years of age or younger when they had LASIK were somewhat more likely to be strongly satisfied than older patients. LASIK significantly reduced difficulties with night driving and nighttime visual disturbances among former contact lens users and former glasses users. The proportion with dry eye symptoms at 1, 2, or 3 years after LASIK was not significantly increased relative to baseline contact lens wear but was significantly increased relative to baseline glasses use, consistent with many glasses users having tried and abandoned contact lenses because of latent dry eye problems. Compared with continued contact lens wear, LASIK significantly reduced the self-reported rates of eye infections, ulcers, and abrasions each year. CONCLUSIONS: Compared with contact lens wear, current LASIK technology improved ease of night driving, did not significantly increase dry eye symptoms, and resulted in higher levels of satisfaction at 1, 2, and 3 years follow-up.

Corneal cross-linking in the treatment of corneal ulcers.

PURPOSE OF REVIEW: New treatments for corneal ulcers are needed to address challenges with antibiotic resistance, cost, and specificity requiring timely pathogen identification. This review assesses the evidence regarding safety and efficacy of corneal cross-linking (CXL) as an adjunct or stand-alone treatment. RECENT FINDINGS: To date approximately 200 clinical cases of CXL used with various types of infectious keratitis have been reported in about 30 publications. Most employed the CXL protocol developed for keratoconus as an adjunct to antibiotics for resistant ulcers, and a number of cases resolved after this intervention. However, a few studies raised concerns about resurgence and perforation when CXL was utilized with deep fungal infections. The infiltrate depth is an important consideration, because the standard CXL treatment is cytotoxic (to keratocytes) to a depth of approximately 200-300 µm and 50% of the energy is absorbed within the first 100 µm. CXL was used successfully as a monotherapy in approximately 16 eyes with early bacterial or shallow fungal infections. SUMMARY: Further work is needed to develop optimized CXL protocols for treatment of corneal ulcers, define the appropriate conditions for use, and determine the safety and efficacy relative to standard antibiotic treatments.

Distinctive and pervasive alterations in aqueous humor protein composition following different types of glaucoma surgery.

PURPOSE: To investigate whether specific glaucoma surgeries are associated with differences in aqueous humor protein concentrations compared to eyes without filters. METHODS: In this cross-sectional study, aqueous humor samples were prospectively collected from control subjects who underwent routine cataract surgery (n=14) and from patients who had different glaucoma filters: Baerveldt aqueous shunt (n=6), Ahmed aqueous shunt (n=6), trabeculectomy (n=5), and Ex-Press trabeculectomy (n=3). Total protein concentrations were determined with Bradford assay. Tryptic digests were analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Proteins were identified with high confidence using stringent criteria and were quantitatively compared with a label-free platform. Relative protein quantities were compared across groups with ANOVA. Post hoc pair-wise comparisons were adjusted for multiple comparisons. RESULTS: Compared to the control eyes, the aqueous humor protein concentration was increased approximately tenfold in the Ahmed and Baerveldt eyes and fivefold in the trabeculectomy and Ex-Press eyes. Overall, 718 unique proteins, splice variants, or isoforms were identified. No differences in the protein concentrations were detected between the Baerveldt and Ahmed groups. Likewise, the trabeculectomy and Ex-Press groups were remarkably similar. Therefore, the aqueous shunt groups were pooled, and the trabeculectomy groups were pooled for a three-way comparison with the controls. More than 500 proteins differed significantly in relative abundance (ANOVA p<0.01) among the control, aqueous shunt, and trabeculectomy groups. Functional analyses suggested these alterations in relative protein abundance affected dozens of signaling pathways. CONCLUSIONS: Different glaucoma surgical procedures were associated with marked increases in the aqueous humor protein concentration and distinctive changes in the relative abundance of numerous proteins involved in multiple signaling pathways.

Repeat Descemet Membrane Endothelial Keratoplasty: Secondary Grafts with Early Intervention Are Comparable with Fellow-Eye Primary Grafts.

PURPOSE: To evaluate the outcomes of secondary Descemet membrane endothelial keratoplasty (DMEK) after failed primary DMEK. DESIGN: Retrospective, interventional case series. PARTICIPANTS: Fifty-five DMEK recipients 42 to 89 years of age. METHODS: An initial consecutive series of 1655 DMEK surgeries was reviewed to identify cases of secondary DMEK after failed primary DMEK (n = 55). A paired fellow-eye analysis was performed with a subgroup of 29 patients who underwent secondary DMEK in 1 eye and successful primary DMEK in the fellow eye. MAIN OUTCOME MEASURES: Corrected distance visual acuity (CDVA), central corneal thickness, and 1-year endothelial cell loss. RESULTS: The median follow-up after DMEK regraft was 18 months (range, 3-61 months). All 55 regrafts cleared, 8 (15%) had air reinjected to promote attachment, 1 eye (2%) with trabeculectomy and progressive synechiae demonstrated late endothelial failure, and no rejection episodes occurred (0%). In the paired analysis, the median duration of endothelial decompensation before the regraft was 21 days (range, 2-133 days). At 1, 3, 6, or 12 months, CDVA did not differ between the primary and secondary grafts in fellow eyes (mean difference, ≤2 Snellen letters; P > 0.05 at all examinations). At 1 year, the visual acuity was ≥20/20 in 61%, ≥20/25 in 81%, and ≥20/40 in 100% of the secondary grafts in the paired analysis, excluding 1 eye with retinal problems. Vision differed by ≤1 line between fellow eyes in all but the 1 patient with the longest time to regraft (133 days), who demonstrated central haze and irregular astigmatism from anterior stromal scarring during that period. At 1 year, CDVA associated with the scarring was 20/40 versus 20/20 for the fellow-eye primary graft. The central corneal thickness was comparable between fellow-eye primary and secondary grafts at 3, 6, and 12 months (mean difference at 1 year, 2 µm; P = 0.57). The 1-year endothelial cell loss was comparable in primary and secondary grafts (27% vs. 31%, respectively; P = 0.58). CONCLUSIONS: In patients who received prompt intervention to minimize the duration of central corneal decompensation, the visual outcomes with secondary DMEK matched the fellow-eye visual outcomes with primary DMEK.

Descemet's membrane endothelial keratoplasty: clinical results of single versus triple procedures (combined with cataract surgery).

PURPOSE: To compare the outcomes of triple Descemet's membrane endothelial keratoplasty (DMEK) versus DMEK alone in pseudophakic eyes. DESIGN: Retrospective, comparative, interventional case series. PARTICIPANTS: Patients with Fuchs' endothelial dystrophy, secondary corneal edema, and prior failed endothelial keratoplasty with or without prior cataract extraction. METHODS: Outcomes of 492 DMEK procedures performed between April 2010 and August 2012 were reviewed; 292 pseudophakic eyes underwent DMEK (group 1) and 200 eyes had concurrent cataract surgery with DMEK (group 2). MAIN OUTCOME MEASURES: Corrected distance visual acuity, endothelial cell loss, immediate and early postoperative complications. RESULTS: The mean age at the time of surgery was 70 years (range, 47-94 years) in group 1 and 64 years (range, 46-90 years) in group 2 (P <0.0001). At 6 months, the median corrected distance visual acuity was 20/25 (range, 20/16-20/80; n = 164) in group 1 and 20/20 (range, 20/16-20/100; n = 121) in group 2 (P <0.0001), excluding 21 eyes with retinal or optic nerve problems. The DMEK graft failed to clear in 9 eyes (3.1%) in group 1 and 7 eyes (3.5%) in group 2 (P = 0.34); all were regrafted successfully with DMEK. No further graft failures occurred during the follow-up period. The air reinjection rate was 30% in group 1 and 29% in group 2 (P = 0.69). The air reinjection rate dropped significantly in both groups, from 45% to 16%, after use of viscoelastic was eliminated during the tissue insertion step. The median endothelial cell loss at 3 to 6 months did not differ significantly between groups (26% in both). CONCLUSIONS: Triple DMEK was not associated with any higher risk of complications than DMEK alone. Compared with sequential management of patients with concomitant cataract and endothelial dysfunction, triple DMEK is an effective strategy in rapid visual rehabilitation and offers the advantage of a 1-stage procedure, with reduced risks and costs.

Long-Term Risk of Steroid-Induced Ocular Hypertension/Glaucoma With Topical Prednisolone Acetate 1% After Descemet Stripping Endothelial Keratoplasty.

PURPOSE: The aim of this study was to assess the long-term risk of steroid-induced ocular hypertension and the need for glaucoma treatment with long-term use of topical prednisolone acetate 1% in patients without preexisting glaucoma. METHODS: We retrospectively reviewed the charts of 211 patients without previous glaucoma, who underwent Descemet stripping endothelial keratoplasty (DSEK) and used topical prednisolone acetate long-term to prevent graft rejection. Dosing was 4 times daily for 4 months and tapered to once daily. The main outcomes were ocular hypertension (defined as intraocular pressure ≥24 mm Hg, or increase of ≥10 mm Hg over baseline) and initiation of glaucoma treatment. RESULTS: The median patient age was 70 years (range: 34-94 years). The indications for DSEK were Fuchs dystrophy (88%), pseudophakic corneal edema (7%), failed DSEK (3%), and failed penetrating keratoplasty (2%). The median follow-up period was 7 years (range, 1-17 years). At 1, 5, and 10 years, the cumulative risks of steroid-induced ocular hypertension were 29%, 41%, and 49%, respectively, and the risks of requiring glaucoma treatment were 11%, 17%, and 25%, respectively. Among 35 eyes treated for glaucoma, 28 (80%) were managed medically and 7 (20%) had filtration surgery. CONCLUSIONS: Long-term use of potent topical corticosteroids, such as prednisolone acetate 1%, entails substantial risk of developing steroid-induced ocular hypertension, so frequent monitoring of intraocular pressure is required. With corneal transplantation, the risk can be mitigated by using techniques with a low inherent risk of rejection, such as Descemet membrane endothelial keratoplasty, whenever possible, to allow earlier reduction of steroid potency.

Case of Progressive Keratoconus With Newly Diagnosed Pellucid Marginal Degeneration After Corneal Cross-Linking.

PURPOSE: The purpose of this study was to document, to our knowledge, the first reported case of keratoconus progression accompanied with newly diagnosed pellucid marginal degeneration after corneal cross-linking (CXL). METHODS: A novel case of further keratoconus progression plus development of pellucid marginal degeneration in the same eye after CXL was documented with supporting evidence from Scheimpflug and optical coherence tomography imaging. RESULTS: A male patient was diagnosed with progressive keratoconus in the left eye and treated with CXL when aged 25 years. Although strongly cautioned not to rub his eyes, he admitted that he continued eye rubbing in association with atopic disease. At a follow-up examination 3.5 years after CXL, progressive keratoconus was detected and pellucid marginal degeneration was newly diagnosed in the left eye. The eye was retreated with CXL. CONCLUSIONS: This case illustrates that progressive keratoconus and pellucid marginal degeneration can occur in the same eye after CXL and demonstrates the deleterious effects that can develop with continued eye rubbing.

Innate Immune Cytokine Levels in Eyes With Late Endothelial Keratoplasty Failure.

PURPOSE: The aim of this study was to compare aqueous humor cytokine levels in eyes with an initial endothelial keratoplasty (EK) that cleared and later decompensated versus control eyes. METHODS: In this prospective case-control study, aqueous humor samples were collected under sterile conditions at the start of planned cataract or EK surgery in normal controls (n = 10), Fuchs dystrophy controls with no previous surgery (n = 10) or previous cataract surgery only (n = 10), eyes with Descemet membrane EK (DMEK) endothelial decompensation (n = 5), and eyes with Descemet stripping EK (DSEK) endothelial decompensation (n = 9). Cytokine levels were quantified with the LUNARIS Human 11-Plex Cytokine Kit and compared using the Kruskal-Wallis nonparametric test and post hoc Wilcoxon pairwise 2-sided multiple comparison test. RESULTS: Levels of granulocyte-macrophage colony-stimulating factor, interferon gamma, interleukin (IL)-1ß, IL-2, IL-4, IL-5, IL-10, IL-12p70, and tumor necrosis factorα did not differ significantly between groups. However, IL-6 was significantly increased in DSEK regraft eyes versus controls without previous ocular surgery. IL-8 was significantly increased in eyes with previous cataract or EK surgery versus eyes without previous surgery, and IL-8 was significantly increased in DSEK regraft eyes versus eyes with previous cataract surgery. CONCLUSIONS: The levels of innate immune cytokines IL-6 and IL-8 were elevated in the aqueous humor of eyes with failed DSEK, but not with failed DMEK. The differences between DSEK and DMEK may be related to the lower inherent immunogenicity of DMEK grafts and/or the more advanced stage of some of the DSEK graft failures at the time of diagnosis and treatment.

Functional Approach to IOL Selection in Eyes With Combined Cataract and Keratoconus With an Option for Refractive Lens Exchange.

PURPOSE: To evaluate spherical intraocular lens (IOL) implantation for cataracts in keratoconic eyes followed by optional refractive toric lens exchange to improve uncorrected visual acuity. METHODS: This retrospective study evaluated cataract surgery outcomes in keratoconic eyes. Eyes treated with a spherical IOL targeted for -2.00 diopters (D) either achieved acceptable manifest refraction and desired exchange with a toric IOL (Group 1); achieved satisfactory manifest refraction and chose to use spectacles or contact lenses (Group 2); or did not achieve acceptable refraction and used contact lenses (Group 3). Group 4 had single-stage toric IOL implantation with plano target. Corrected and uncorrected distance visual acuity (CDVA and UDVA) and keratometry were analyzed. RESULTS: Groups 1 to 4 had 18, 23, 18, and 26 eyes, respectively. A staged toric exchange resulted in significantly better (P = .02) UDVA (mean: 0.15 logMAR; 20/25 Snellen) than initial toric IOL implantation (0.24 logMAR; 20/30 Snellen). All toric IOL exchange eyes achieved 20/30 or better CDVA and 94% had 20/40 or better UDVA. Mean manifest cylinder significantly decreased from 3.39 D before lens exchange to 1.10 D postoperatively. CONCLUSIONS: Initial implantation of a spherical IOL in keratoconic eyes allows basing toric calculations on the manifest refraction, which may be more reliable than keratometry measurements in keratoconic eyes. UDVA after staged toric IOL exchange was significantly better than after initial toric IOL implantation. Importantly, by staging use of toric lenses, the authors avoided cases where patients required a rigid contact lens after a toric IOL was implanted. [J Refract Surg. 2024;40(4):e207-e217.].

Initial results of DMEK combined with cataract surgery and implantation of the light-adjustable lens.

PURPOSE: To evaluate the use of light-adjustable intraocular lenses (LALs) to maximize visual acuity (VA) postoperatively in eyes undergoing combined Descemet membrane endothelial keratoplasty (DMEK) and cataract surgery. SETTING: Private practice, tertiary referral center. DESIGN: Retrospective review of initial case series. METHODS: Patients with Fuchs endothelial dystrophy had DMEK combined with phacoemulsification and LAL implantation. Lenses were adjusted based on postoperative manifest refraction and locked-in 3 to 6 months postoperatively. Adjustments to the LAL were started after stabilization of refraction at sequential examinations. Outcomes were uncorrected near and distance VA and manifest refraction 3 to 6 months after locking the lens. RESULTS: A total of 27 eyes in 17 patients with mean age of 65 years (range 53 to 75 years) were included in this study. 6 eyes (22%) had either a near or intermediate target, and 21 eyes (78%) had a distance target. After lock-in, 57% of eyes with a distance target had uncorrected distance VA (UDVA) of 20/20 or better, 90% were 20/25 or better, and 100% were 20/40 or better. After lens lock-in, 100% of eyes had corrected distance VA (CDVA) of 20/20 or better, 86% had postoperative UDVA the same or better than preoperative CDVA, and 100% of eyes had UDVA within 1 line of the preoperative CDVA. In total, 93% of eyes were within 1 diopter (D) of spherical target, and 93% of eyes had ≤0.5 D of refractive cylinder postoperatively. CONCLUSIONS: Combining DMEK with LAL implantation provided significantly better UDVA and refractive outcomes than previously reported data on combined implantation of a standard monofocal lens.

Estrogen genotoxicity causes preferential development of Fuchs endothelial corneal dystrophy in females.

Fuchs endothelial corneal dystrophy (FECD) is a genetically complex, age-related, female-predominant disorder characterized by loss of post-mitotic corneal endothelial cells (CEnCs). Ultraviolet-A (UVA) light has been shown to recapitulate the morphological and molecular changes seen in FECD to a greater extent in females than males, by triggering CYP1B1 upregulation in females. Herein, we investigated the mechanism of greater CEnC susceptibility to UVA in females by studying estrogen metabolism in response to UVA in the cornea. Loss of NAD(P)H quinone oxidoreductase 1 (NQO1) resulted in increased production of estrogen metabolites and mitochondrial-DNA adducts, with a higher CEnC loss in Nqo1-/- female compared to wild-type male and female mice. The CYP1B1 inhibitors, trans-2,3',4,5'-tetramethoxystilbene (TMS) and berberine, rescued CEnC loss. Injection of wild-type male mice with estrogen (E2; 17ß-estradiol) increased CEnC loss, followed by increased production of estrogen metabolites and mitochondrial DNA (mtDNA) damage, not seen in E2-treated Cyp1b1-/-male mice. This study demonstrates that the endo-degenerative phenotype is driven by estrogen metabolite-dependent CEnC loss that is exacerbated in the absence of NQO1; thus, explaining the mechanism accounting for the higher incidence of FECD in females. The mitigation of estrogen-adduct production by CYP1B1 inhibitors could serve as a novel therapeutic strategy for FECD.