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Summary Here, we evaluate the efficacy of cryopreserved human embryonic stem cell (hESC)-derived corneal endothelial cells (CECs) to form a functional monolayer of corneal endothelium (CE) in rabbits and monkeys. We injected cryopreserved hESC-derived CECs into the anterior chamber of rabbits and monkeys either immediately after mechanical scraping of the central CE or a few days later when corneal edema developed. All preclinical models developed deturgesced and clear corneas following the injection of cryopreserved hESC-derived CECs and remained comparable to the corneas of the untreated eye. Confocal scanning microscopy confirmed an intact structure of hexagonal/polygonal cells and immunohistochemical analysis illustrated a monolayer expressing barrier and pump function proteins in the regenerated CE. The necropsy examination confirmed no remarkable change in multiple tissues assessed for teratoma formation. In conclusion, our data demonstrate the efficacy of cryopreserved hESC-derived CECs to form a functional CE on the denuded Descemet's membrane., Highlights • RNA-Seq confirmed similar transcriptomes of non-cryopreserved and cryopreserved hESC-derived CECs. • All preclinical models developed clear corneas following the injection of cryopreserved hESC-derived CECs. • The transparency of the regenerated corneas remained comparable to the corneas of the untreated eye. • Necropsy examination confirmed no remarkable change and/or teratoma formation in all preclinical models., In this article, Ali and colleagues show that intracameral injection of cryopreserved hESC-derived CECs can form a functional CE in rabbits and monkeys.

The lid margins are essential to maintain a healthy tear film and distribute it over the ocular surface to achieve an optimal refractive interface. Alterations in the lid margin structures and func...

Purpose To investigate changes at a molecular level in the mouse corneal endothelium (CE) exposed to chronic cigarette smoke (CS). Methods Pregnant mice (gestation days 18-20) were placed in a whole-body exposure smoking chamber, and a few days later pups were born. After 3.5 months of CS exposure, a ConfoScan4 scanning microscope was used to examine the corneal endothelial cells (CECs) of CS-exposed and control (Ct) mice. The CE was peeled under a microscope and maintained as four biological replicates (two male and two female) for CS-exposed and Ct mice; each replicate consisted of 16 CEs. The proteome of the CE was investigated through mass spectrometry. Results The CE images of CS-exposed and Ct mice revealed a difference in the shape of CECs accompanied by a nearly 10% decrease in CEC density (P < 0.00003) following CS exposure. Proteome profiling identified a total of 524 proteins exhibiting statistically significant changes in CE from CS-exposed mice. Importantly, proteins associated with Descemet's membrane (DM), including COL4α1, COL4α2, COL4α3, COL4α4, COL4α5, COL4α6, COL8α1, COL8α2, and FN1, among others, exhibited diminished protein levels in the CE of CS-exposed mice. Conclusions Our data confirm that exposure to CS results in reduced CEC density accompanied by diminished levels of multiple collagen and extracellular matrix proteins associated with DM.

In this clinical research project, we will conduct a highly rigorous clinical trial where we randomize the patients between umbilical cord (UC)-derived mesenchymal stem cell (MSC) and standard of care (SOC). This study will ask the question whether the allogenic MSCs are effective in reducing death and/or progression of COVID-19 disease when administered to patients with moderate to severe symptoms. MSCs are unique group of cells with minimal immune reactivity and produce multiple beneficial effects, which include reduction of severe inflammatory reaction. There is convincing evidence from human studies that intravenous (IV) delivery of MSCs can directly impact the hyper-inflammatory responses of COVID-19 induced injury of the heart and lungs. Our study will evaluate the safety and efficacy of allogenic UC-derived MSCs administered intravenously to COVID-19 patients with moderate to severe symptom in a randomized, controlled clinical trial. In addition, we will determine whether : (i) UC-derived MSCs are effective in reducing 30-day all-cause mortality (primary endpoint) and (ii) UC-derived MSCs are effective in preventing progression to mechanical ventilation, and/or reducing an inflammatory response, and/or improving overall patient condition (secondary endpoints).

Purpose Although Fuchs corneal dystrophy (FCD) is considered an eye disease, a small number of studies have identified genes related to both FCD and hearing loss. Whether FCD is related to hearing loss is unknown. Method This is a case–control study comparing pure-tone audiometry hearing thresholds in 180 patients with FCD from a hospital-based ophthalmology clinic with 2,575 population-based controls from a nationally representative survey, the National Health and Nutrition Examination Survey (from cycles 2005-06 and 2009-10). Generalized estimating equations were used to compare mean better-hearing ear thresholds in the 2 groups adjusted for age, sex, race, and noise exposure. Results Patients with FCD had higher hearing thresholds (worse hearing) in lower frequencies (mean difference at 0.5 kHz = 3.49 dB HL) and lower hearing thresholds (better hearing) in higher frequencies (difference at 4 kHz = −4.25 dB HL) compared with population-based controls. Conclusion In the first study to use objectively measured hearing, FCD was associated with poorer low-frequency and better high-frequency audiometric thresholds than population controls. Further studies are needed to characterize this relationship.

PURPOSE: Alternative splice isoforms of TCF4, a gene implicated in Fuchs corneal dystrophy, have been identified in multiple human tissues outside the eye. We aimed to identify the transcriptional profile of TCF4 in corneal endothelium. METHODS: We extracted RNA from donor corneal endothelium and performed rapid amplification of cDNA ends (RACE). We tested the expression pattern of one newly identified isoform (7b) in a panel of cDNA derived from multiple human tissues and included cDNA from corneal endothelial and RPE cell lines. To further delineate the differential expression of TCF4 splice variants that span CTG18.1, we analyzed the expression of six alternative splice isoforms that are transcribed from either exon 2 or 3 in RNA extracted from corneal endothelium of three normal donors and a corneal endothelial cell line. RESULTS: We identified 11 different isoforms in control corneal endothelial tissue, including one isoform (7b) not reported previously. This isoform is enriched in the corneal endothelium and placenta specifically compared to other tissues in a panel of human cDNA. CONCLUSIONS: We demonstrate the complex expression profile of TCF4 in human corneal endothelium, and reveal the expression of alternative splice variants of TCF4.

The structure of the cornea is vital to its transparency, and dystrophies that disrupt corneal organization are highly heritable. To understand the genetic aetiology of Fuchs endothelial corneal dystrophy (FECD), the most prevalent corneal disorder requiring transplantation, we conducted a genome-wide association study (GWAS) on 1,404 FECD cases and 2,564 controls of European ancestry, followed by replication and meta-analysis, for a total of 2,075 cases and 3,342 controls. We identify three novel loci meeting genome-wide significance (P, Fuchs endothelial corneal dystrophy (FECD) is one of the most common reasons for corneal transplantation, and is known to cluster in families. Here, the authors discover new genetic loci associated with FECD with sex-specific effects and implications for disease mechanism.

Purpose: Diagnostic criteria for monoclonal gammopathy of undetermined significance (MGUS) do not currently include ocular phenotypic changes. Here, we offer a new diagnostic approach that is useful in patients with posteriorly located corneal depositions and present evidence to support the theory that the aqueous humor is a source for monoclonal proteins accumulated in the cornea. Observations: A 77-year-old woman presented to the clinic with a gradual decrease in visual acuity over 6 months. Slit lamp examination revealed bilateral central guttae consistent with Fuchs corneal dystrophy, peripheral circular band-like corneal opacities in the deep stroma, and bilateral nuclear sclerotic and cortical cataracts. Anterior segment optical coherence tomography confirmed corneal opacities in the posterior stroma and Descemet membrane. Immunological studies revealed increased serum IgG levels of 3220 mg/dL and serum electrophoresis showed an abnormal monoclonal band of 2.4 g/dL identified as IgG lambda by immunofixation electrophoresis. The patient was referred to the hematology clinic where she underwent further systemic workup and was diagnosed with MGUS. Immunofixation electrophoresis of aqueous sampling, which was performed at the time of cataract surgery, confirmed the presence of the IgG lambda gammopathy in the anterior chamber. Conclusions and importance: Monoclonal gammopathy, although rare, should be included in the differential diagnosis of corneal opacities, as the ocular finding can be the initial manifestation of a systemic disease that can potentially be life-threatening. When corneal biopsy is not feasible due to the location of corneal pathology, aqueous sampling may be an alternative approach towards a clinical diagnosis. We propose a new terminology, “monoclonal gammopathy of ocular significance,” for patients diagnosed with MGUS, however, their only significant clinical finding is ocular manifestation. Keywords: Cornea, Deposition, Monoclonal gammopathy of undetermined significance, Paraproteinemic keratopathy, Lambda, Immunofixation

Purpose Retroillumination photography analysis is an objective tool for the assessment of the number and distribution of guttae in eyes affected with Fuchs corneal dystrophy (FCD). Current protocols include manual processing of images; here, we assess validity and interrater reliability of automated analysis across various levels of FCD severity. Methods Retroillumination photographs of 97 FCD-affected corneas were acquired, and total counts of guttae were previously summated manually. For each cornea, a single image was loaded into ImageJ software. We reduced color variability and subtracted background noise. Reflection of light from each gutta was identified as a local area of maximum intensity and counted automatically. Noise tolerance level was titrated for each cornea by examining a small region of each image with automated overlay to ensure appropriate coverage of individual guttae. We tested interrater reliability of automated counts of guttae across a spectrum of clinical and educational experience. Results A set of 97 retroillumination photographs was analyzed. Clinical severity as measured by a modified Krachmer scale ranged from a severity level of 1 to 5 in the set of analyzed corneas. Automated counts by an ophthalmologist correlated strongly with Krachmer grading (R = 0.79) and manual counts (R = 0.88). Intraclass correlation coefficients demonstrated strong correlation at 0.924 (95% CI, 0.870-0.958) among cases analyzed by 3 students, and 0.869 (95% CI, 0.797-0.918) among cases for which images were analyzed by an ophthalmologist and 2 students. Conclusions Automated retroillumination photography analysis allows for grading of FCD severity with high resolution across a spectrum of disease severity.

Purpose Fuchs dystrophy is the leading indication of corneal transplantation in the United States. A CTG18.1 trinucleotide repeat in TCF4 correlates with increased severity in Fuchs dystrophy; however, quantitative estimates of increased transplantation risk, including effects of age and sex, are unclear. Methods In a tertiary institution clinical practice, 574 participants were enrolled in a longitudinal study of Fuchs dystrophy after slit-lamp biomicroscopy confirmed significant central guttae and/or corneal transplantation in both eyes. We documented clinical history, examination findings, and demographic information. We acquired blood samples, extracted DNA, and sequenced the CTG18.1 trinucleotide repeat in TCF4. In this retrospective case-control study, the number of participants with triplet expansion, defined as greater than 40 CTG repeats, and transplantation status were assessed. Kaplan-Meier estimates of timing and transplantation events were produced. The Cox proportional hazard regression model was used to assess the relationship between age, sex, triplet expansion, and surgery. Results A total of 106 participants (18.5%) previously underwent corneal transplantation in at least 1 eye at the time of initial evaluation. A higher proportion of individuals harboring allele expansion had undergone transplantation (78/357, 21.8%) compared with those without the expanded allele (28/217, 12.9%), a significant association (P = 0.007). The log-rank test demonstrates a significant difference in survival function over time (P = 0.027), with a hazard ratio of 1.64 (95% confidence interval, 1.05-2.55). Conclusions Expansion of the TCF4 CTG trinucleotide repeat was associated with 1.64 times higher likelihood of corneal transplantation at a given age in patients with Fuchs dystrophy.

The corneal endothelium (CE), a monolayer of hexagonal cells constitutes the innermost layer of the cornea that is critical in maintaining clarity by mediating hydration through barrier and pump functions. Corneal endothelial cells (CECs) have limited proliferative potential and therefore generation of CECs has been undertaken by many groups. We previously reported generation of CECs from peripheral blood mononuclear cell (PBMC)-originated, induced pluripotent stem cells (iPSCs). In here, we extend our analysis through next-generation seqeuncing based transcriptome profiling of H9 human embryonic stem cell (hESC)- and human PBMC-originated, iPSC-derived CECs. The differentiating CECs on day 20 (D20) exhibited a tightly packed hexagonal/polygonal shape expressing zona occludens-1 (ZO-1) and N-cadherin at the cell boundaries. Next-generation RNA sequencing of hESC- and iPSC-derived CECs detected expression (≥0.659 RPKM) of 13,546 and 13,536 genes, respectively. Comparative transcriptome analysis of hESC- and iPSC-derived CECs revealed 13,208 (>96%) genes common in both transcriptomes. Among the 13,208 genes common in these transcriptomes, 12,580 (>95%) exhibited a quantitatively similar expression. To the best of our knowledge, this is the first report presenting comparative transcriptome analysis of hESC- and iPSC-derived CECs.

Fuchs corneal dystrophy (FCD) is a hereditary dystrophy of the corneal endothelium and is responsible for majority of the corneal transplantation performed in the United States. Here, we describe three generations of a family with 12 individuals affected by late-onset FCD and in which three individuals are unaffected. Genome-wide mapping provided suggestive linkage at two loci on chromosomal arms 3p and 15q. Alleles at either locus alone were not sufficient to explain FCD; however, considered together, both loci could explain the disorder in this pedigree. Subsequent next-generation sequencing identified a nonsense mutation in AGBL1 in the 15q locus; this mutation would result in a premature termination of AGBL1. Consistent with a causal role for this transcript, further sequencing of our cohort of late-onset-FCD-affected individuals identified two cases harboring the same nonsense mutation and a further three unrelated individuals bearing a second missense allele. AGBL1 encodes a glutamate decarboxylase previously identified in serial analysis of gene expression of corneal endothelium, a finding confirmed by immunohistochemical staining. Wild-type AGBL1 localizes predominantly to the cytoplasm; in sharp contrast, the truncated protein showed distinct nuclear localization. Finally, we show that AGBL1 interacts biochemically with the FCD-associated protein TCF4 and that the mutations found in our cohort of FCD individuals diminish this interaction. Taken together, our data identify a locus for FCD, extend the complex genetic architecture of the disorder, provide direct evidence for the involvement of TCF4 in FCD pathogenesis, and begin to explain how causal FCD mutations affect discrete biochemical complexes.

Purpose The p.(Leu450Trp) substitution in Collagen, Type VIII, Alpha 2 (COL8A2) is associated with an early-onset corneal dystrophy. Here we identify distinct anterior corneal and keratorefractive changes associated with this disease and replicate its distinguishing endothelial characteristics in a new family. Methods We reviewed clinical data from a large family associated with the p.(Leu450Trp) COL8A2 mutation. We compared clinical photographs and keratometry over an 11-year period. We sought to replicate these findings, and after a 40-year-old male subject presented similarly, we obtained a peripheral blood sample and sequenced COL8A2. Results Of 10 individuals with the p.(Leu450Trp) substitution, clinical records noted corneal edema in 6, of which 4 showed epithelial microcystic edema. Eleven-year progression data reveal a marked increase in subepithelial corneal edema and gradual, profound increase in anterior corneal astigmatism. Sequencing of genomic DNA from the unrelated individual predictably identified a c.1349T>G [p.(Leu450Trp)] heterozygous variation in COL8A2. Confocal microscopy confirmed attenuated endothelium, and histopathology revealed no guttae, consistent with findings from a previously identified family. Conclusions Peripheral, anterior microcystic corneal edema represents a characteristic aspect of the phenotype associated with the p.(Leu450Trp) substitution in COL8A2, in at least 2 of 3 known affected families worldwide. We describe long-term progression and Descemet stripping endothelial keratoplasty for this disease for the first time.

FOXE3 is a lens-specific transcription factor that has been associated with anterior segment ocular dysgenesis. To determine the transcriptional target(s) of FOXE3 that are indispensable for the anterior segment development, we examined the transcriptome and the proteome of cells expressing truncated FOXE3 responsible for Peters anomaly identified through linkage-coupled next-generation whole-exome sequencing. We found that DNAJB1, an autophagy-associated protein, was the only candidate exhibiting differential expression in both screens. We confirmed the candidacy of DNAJB1 through chromatin immunoprecipitation and luciferase assays while knockdown of DNAJB1 in human lens epithelial cells resulted in a mitotic arrest. Subsequently, we targeted dnajb1a in zebrafish through injection of a splice-blocking morpholino. The dnajb1a morphants exhibited underdeveloped cataractous lenses with persistent apoptotic nuclei. In conclusion, here we report DNAJB1 is a transcriptional target of FOXE3 in a novel pathway that is crucial for the development of the anterior segment of the eye., Peter's Anomaly is a developmental disorder of the eye and has been linked to mutations in a range of genes, including the transcription factor FOXE3. Here the authors use next-generation RNA sequencing and mass spectrometry to identify an autophagy-associated protein, DNAJB1 as the transcriptional target of FOXE3.

Purpose Corneal endothelial cells (CECs) are critical in maintaining clarity of the cornea. This study was initiated to develop peripheral blood mononuclear cell (PBMC)-originated, induced pluripotent stem cell (iPSC)-derived CECs. Methods We isolated PBMCs and programmed the mononuclear cells to generate iPSCs, which were differentiated to CECs through the neural crest cells (NCCs). The morphology of differentiating iPSCs was examined at regular intervals by phase contrast microscopy. In parallel, the expression of pluripotent and corneal endothelium (CE)-associated markers was investigated by quantitative real-time PCR (qRT-PCR). The molecular architecture of the iPSC-derived CECs and human corneal endothelium (hCE) was examined by mass spectrometry-based proteome sequencing. Results The PBMC-originated, iPSC-derived CECs were tightly adherent, exhibiting a hexagonal-like shape, one of the cardinal characteristics of CECs. The CE-associated markers expressed at significantly higher levels in iPSC-derived CECs at days 13, 20, and 30 compared with their respective levels in iPSCs. It is of importance that only residual expression levels of pluripotency markers were detected in iPSC-derived CECs. Cryopreservation of iPSC-derived CECs did not affect the tight adherence of CECs and their hexagonal-like shape while expressing high levels of CE-associated markers. Mass spectrometry-based proteome sequencing identified 10,575 proteins in the iPSC-derived CEC proteome. In parallel, we completed proteome profiling of the hCE identifying 6345 proteins. Of these, 5763 proteins were identified in the iPSC-derived CECs, suggesting that 90.82% of the hCE proteome overlaps with the iPSC-derived CEC proteome. Conclusions We have successfully developed a personalized approach to generate CECs that closely mimic the molecular architecture of the hCE. To the best of our knowledge, this is the first report describing the development of PBMC-originated, iPSC-derived CECs.

Patients with decreased vision due to Fuchs corneal dystrophy and cataract can present with a number of challenges to determine the best surgical option for restoring sight. The ophthalmologist must first distinguish how much of the vision loss is due to the cataract versus the Fuchs corneal dystrophy (FCD) before determining the best surgical course, either cataract surgery alone or cataract surgery combined with full thickness or lamellar keratoplasty. This review will discuss the various techniques and clinical signs to ascertain the source of vision loss and how to use this clinical information to help guide the surgical decision making process in order to optimize the best possible outcome.Over the last several years, the technique of endothelial keratoplasty has evolved to become an important alternative in the treatment of FCD. Anticipating the correct intraocular lens power for a patient undergoing cataract surgery alone followed by Descemet stripping endothelial keratoplasty (DSEK) or combined cataract surgery with DSEK requires understanding the hyperopic shift that can occur with DSEK and incorporating this correction preoperatively in the intraocular lens power selection.New developments in the surgical treatment of Fuchs corneal dystrophy have greatly enhanced our ability to restore vision and reduce the dependence on contact lenses in this genetic disease.

Purpose To report secondary angle closure caused by air migrating behind the pupil in the context of intraocular pressure (IOP) elevation in the early postoperative period after Descemet stripping endothelial keratoplasty (DSEK). Methods A retrospective case series was conducted on 100 consecutive DSEK cases from 90 patients undergoing DSEK because of corneal disease from Fuchs corneal dystrophy, pseudophakic bullous keratopathy, aphakic bullous keratopathy, and iridocorneal endothelial syndrome. Preoperative and postoperative slit-lamp examinations and IOP measurements were ascertained for all 100 eyes. Main outcome measures included preoperative and postoperative IOP. Results Thirteen of 100 eyes developed an IOP rise of greater than 30 mm Hg on the first postoperative day. Six of these 13 patients developed angle closure from air migrating posterior to the iris and causing iridocorneal adhesions. One of these 13 patients developed pupillary block from air anterior to iris. Six of 13 patients developed increased IOP without pupillary block or iridocorneal adhesions and had a history of preexisting primary or secondary glaucoma. Conclusions A secondary angle closure associated with DSEK is reported with air migrating behind the iris, resulting in extensive iridocorneal adhesions. An acute increase in IOP after DSEK can also be induced by air anterior to the iris causing pupillary block. IOP spikes are much more common in the first few postoperative days after DSEK. Medical treatment can occasionally resolve air posterior to the iris, but if iridocorneal adhesions are extensive and persistent, air removal and angle reformation may be necessary.

The cornea is a transparent tissue with significant refractive and barrier functions. The epithelium serves as the principal barrier to fluid and pathogens, a function performed through production of tight junctions, and constant repopulation through differentiation and maturation of dividing cells in its basal cell layer. It is supported posteriorly by basement membrane and Bowman's layer and assists in maintenance of stromal dehydration. The stroma composes the majority of corneal volume, provides support and clarity, and assists in ocular immunity. The posterior cornea, composed of Descemet membrane and endothelium, is essential for stromal dehydration, maintained through tight junctions and endothelial pumps. Corneal development begins with primitive formation of epithelium and lens, followed by waves of migration from cells of neural crest origin between these two structures to produce the stroma and endothelium. Descemet membrane is secreted by the latter and gradually thickens.

PURPOSE To describe the morphologic features of Fuchs corneal dystrophy and compare them with those of bullous keratopathy. METHODS This was an observational case series. The study group consisted of 32 corneal buttons with a diagnosis of Fuchs dystrophy and the comparison group consisted of 22 corneal buttons with bullous keratopathy. Morphologic analysis was performed of corneal buttons from patients with the clinical diagnosis of Fuchs dystrophy or bullous keratopathy by light and electron microscopy. RESULTS The main outcome measure was identification of degenerated keratocytes, granular material in and around keratocytes, and lipid keratopathy. The overall morphologic features of Fuchs dystrophy and bullous keratopathy are similar to those described in previous literature. A high proportion of keratocytes exhibited degenerative changes (78.9% in Fuchs dystrophy versus 50.5% in bullous keratopathy). Granular material was identified in and around variably degenerated keratocytes in all cases of Fuchs dystrophy and in 14 of 22 (64%) of the corneas with bullous keratopathy. The percentage of keratocytes with granular deposits was higher in Fuchs dystrophy corneas as compared with corneas with bullous keratopathy (51.7% versus 14.1%, P < 0.0005). Lipid keratopathy was a common occurrence in both Fuchs dystrophy and bullous keratopathy (23/32 [72%] versus 12/22 [55%]). CONCLUSIONS Histopathologic changes in the corneal stroma and keratocytes occur in Fuchs dystrophy. Secondary lipid keratopathy ensues and may contribute to corneal haze. A higher proportion of keratocytes in Fuchs dystrophy have granular deposit than in bullous keratopathy. That a high proportion of keratocytes had degenerative changes in both Fuchs dystrophy and bullous keratopathy suggests that keratocytes may degenerate secondary to altered stromal microenvironment because of endothelial cell loss.

Objective To evaluate the use of preoperative pachymetry in patients with Fuchs' dystrophy who are undergoing cataract extraction to predict the need for future penetrating keratoplasty and to compare these findings with current published recommendations. Design Retrospective noncomparative case series. Participants A series of patients with Fuchs' dystrophy (136 eyes) undergoing cataract surgery. Methods We reviewed the medical records of 136 patients with Fuchs' dystrophy who underwent phacoemulsification and intraocular lens implantation between October 1990 and May 2002. Main outcome measures Preoperative and postoperative visual acuity, pachymetry, and postoperative corneal decompensation requiring penetrating keratoplasty. Results The average preoperative corneal thickness was 584±39.5 μm (range, 482–674 μm). Fifty eyes (36.8%) had preoperative corneal thickness of ≥600 μm. The average postoperative best-corrected visual acuity (BCVA) was 20/33 (range, 20/15–20/250). Of the 50 eyes with preoperative pachymetry measurements of ≥600 μm, 5 (10%) progressed to penetrating keratoplasty; 90% of the 50 eyes did not need corneal transplants within the first year after cataract surgery and had an average postoperative BCVA of 20/35 (range, 20/20–20/200). Of those with a corneal thickness of ≥640 μm, 83% did not need a corneal transplant within this same time period and had an average postoperative BCVA of 20/50 (range, 20/20–20/200). Conclusions To avoid unnecessary cost and delay in visual rehabilitation, we suggest changing the current recommendations for an initial triple procedure for eyes with preoperative pachymetry measurements of >600 μm. Our data suggest that current cataract removal techniques allow for excellent visual rehabilitation in patients with Fuchs' dystrophy who have a preoperative corneal thickness of >600 μm, and we suggest that preoperative pachymetry measurements of >640 μm may be a better guideline. This recommendation can be further expanded above 640 μm if a visual acuity of less than 20/20 is acceptable. A prospective randomized controlled study is required for validation of this analysis.

Corneal deposits in association with paraproteinemias have been well described in the ophthalmic literature. Recent reports in the renal literature have described immunotactoid deposition associated with glomerulopathy—organized microtubular deposits of IgGκ that measured 32–50 nm in diameter on renal biopsies. We present a case of corneal immunotactoid deposition in the setting of chronic lymphocytic leukemia and review previous reports of corneal deposition in the setting of systemic paraproteinemia, highlighting the etiology, differential diagnosis, prognosis, and treatment of corneal involvement. We propose the use of the term immunotactoid keratopathy to describe corneal IgGκ deposits appearing as tubular, electron-dense, crystalloid deposits with a central lucent core on electron microscopy and suggest that these patients undergo directed systemic workup to evaluate for potential etiologies of their systemic paraproteinemia. To illustrate the spectrum of paraprotein deposition in the cornea, and to emphasize the importance of ophthalmic evaluation in the setting of systemic paraproteinemias, we include a case of a 44-year-old man with immunoprotein corneal deposition who was subsequently diagnosed with multiple myleoma.

Purpose To report the preoperative, intraoperative, and postoperative outcomes of combining phacoemulsification and posterior chamber intraocular lens (IOL) implantation with pars plana vitrectomy in eyes with significant cataract and coexisting vitreoretinal pathology. Design Retrospective, consecutive, interventional case series. Methods Charts of patients undergoing combined procedures at the Wilmer Ophthalmologic Institute between March 1995 and May 2000 were reviewed. Results In all, 122 eyes of 111 patients were identified. Patient ages ranged from 27 to 89 years (mean 65). Forty-three eyes had diabetic retinopathy; 11 had undergone vitrectomy previously. Macular pathology (hole, membrane, choridal neovascularization) was present in 69 eyes. The most common indications for surgery were diabetic vitreous hemorrhage, macular hole, epiretinal membrane, and retinal detachment. In all cases, phacoemulsification and IOL implantation were performed before vitreoretinal surgery. Preoperative vision ranged from 20/30 to light perception and postoperative vision ranged from 20/20 to no light perception. In 105 patients vision improved, in 7 there was no change, and in 10 vision decreased. Postoperative complications included opacification of the posterior capsule, increased intraocular pressure, corneal epithelial defects, vitreous hemorrhage, retinal detachment and iris capture by the IOL. Conclusions Combined surgery is a reasonable alternative in selected patients. Techniques that may simplify surgery and reduce complications include: careful, limited, curvilinear capsulorhexis; in-the-bag placement of IOLs; use of IOLs with larger optics; suturing of cataract wounds before vitrectomy; use of miotics and avoidance of long-acting dilating drops in patients with intravitreal gas; and use of wide-field viewing systems.

Fuchs corneal dystrophy (FCD) is a hereditary, progressive disease of the posterior cornea which results in excrescences of Descemet membrane, endothelial cell loss, corneal edema, and, in late stages, bullous keratopathy. Structural changes are noted principally in Descemet membrane and the endothelium, with thickening of Descemet membrane, loss of barrier function, and increased corneal hydration, although secondary effects occur throughout all layers. Multiple chromosomal loci and, more recently, causal genetic mutations have been identified for this complex disorder, including in TCF8, SLC4A11, LOXHD1, and AGBL1. A trinucleotide repeat in TCF4 correlates strongly with disease status and interacts in common pathways with previously identified genes. Dysregulation of pathways involving oxidative stress and apoptosis, epithelial-to-mesenchymal transition, microRNA, mitochondrial genes, and unfolded protein response has been implicated in FCD pathogenesis.

The cornea is a transparent tissue with significant refractive and barrier functions. The epithelium serves as the principal barrier to fluid and pathogens, a function performed through production of tight junctions, and constant repopulation through differentiation and maturation of dividing cells in its basal cell layer. It is supported posteriorly by basement membrane and Bowman's layer and assists in maintenance of stromal dehydration. The stroma composes the majority of corneal volume, provides support and clarity, and assists in ocular immunity. The posterior cornea, composed of Descemet membrane and endothelium, is essential for stromal dehydration, maintained through tight junctions and endothelial pumps. Corneal development begins with primitive formation of epithelium and lens, followed by waves of migration from cells of neural crest origin between these two structures to produce the stroma and endothelium. Descemet membrane is secreted by the latter and gradually thickens.

PURPOSE: To localize a gene causing a newly described autosomal dominant anterior segment dysgenesis characterized by corneal endothelial dystrophy, iris hypoplasia, congenital cataracts, and corneal stromal thinning (EDICT syndrome). DESIGN: Experimental study. METHODS: A set of microsatellite markers spanning the 22 human autosomes was used to perform linkage analysis on affected and unaffected individuals within a single family. RESULTS: Linkage analysis of the anterior segment dysgenesis endothelial dystrophy, iris hypoplasia, congenital cataract, and stromal thinning (EDICT) syndrome in this family revealed a logarithm of the odds (LOD) score of 2.71 on chromosome 15q22.1–25.3 between markers D15993 and D15S202. These results suggest a gene for EDICT syndrome lies in this chromosomal region. CONCLUSIONS: A LOD score of 2.71 suggests a novel locus associated with the newly described EDICT syndrome lies in a region of chromosome 15 between markers D15S993 and D15S202. Identification of the disease-causing gene in this region may yield insights into a broad range of disorders affecting the corneal stroma, endothelium, iris, and lens.

Purpose Studies of Fuchs' dystrophy have largely focused on individuals of European origin. Characterization of disease among African Americans is required to ensure prognostic factors and therapeutic approaches are applicable across diverse patient populations. Methods We assessed all self-reported black and white patients aged older than 40 years at a tertiary care institution with a diagnosis of cataract over a 3-year period for concurrent diagnosis of Fuchs' dystrophy. Affected patients in a longitudinal cohort were invited to provide a blood sample from which we extracted genomic DNA. The CTG18.1 trinucleotide repeat length was determined using a two-step, triplet repeat primed PCR protocol. Expansion was defined as >40 CTG repeats. Demographic information, including race, was documented. Results Of 59,365 self-reported black and white adults who presented for cataract evaluation, the odds ratio of presenting with Fuchs' dystrophy among black compared to white patients was 0.6992 (95% confidence interval [CI], 0.6210-0.7872). A total of 60 black and 549 white patients with Fuchs' corneal dystrophy enrolled in the longitudinal study, of which 21 (35.0%) black and 343 (62.5%) white patients demonstrated trinucleotide repeat expansion, a significant difference (P = 7.7 × 10-5). In a multivariable linear regression model, repeat expansion but not race was significantly associated with mean clinical grading of severity. Conclusions Black patients with Fuchs' dystrophy were less likely than white patients to demonstrate CTG18.1 allele expansion. The data contribute to our understanding of population differences in clinical presentation, and highlight the need for considering diversity of patient populations in clinical research.

A previously healthy 80-year-old man had uneventful clear corneal cataract extraction. An extensive peripheral corneal infiltrate with overlying epithelial defect at the incision site was noted at the regular follow-up visit 1 week after surgery. Corneal cultures showed no evidence of infectious keratitis. A systemic evaluation uncovered early-stage, active rheumatoid arthritis. This case illustrates that peripheral ulcerative keratitis may occur with a small clear corneal incision and may be the presenting sign of a previously undiagnosed rheumatoid disease.

For decades aminoglycosides have been used routinely in intraocular surgery to prevent and treat endophthalmitis. However, as more and more studies are conducted, the reality is that these drugs are causing more harm than they are preventing. Summarized herein are the most recent studies concluding that even low-dose aminoglycosides can cause toxic retinal damage. The conclusion, with pertinent recommendations from the Johns Hopkins Hospital, Wilmer Eye Institute Infection Control Committee, is that the questionable benefit of use of aminoglycosides intraoperatively is not justified by the risk of injury.

PURPOSE: To report a case of herpes zoster sine herpete presenting with hyphema. METHODS: A 69-year-old man was referred for traumatic hyphema and corneal edema in his left eye after a sandblast exposure three weeks previously. Slit-lamp examination demonstrated hyphema, anterior chamber inflammation, mid-dilated pupil, impaired corneal sensation, and high intraocular pressure, without any facial skin lesions. Iris fluorescein angiography revealed tortuosity and extensive occlusion of iris vessels. The patient was treated with oral acyclovir and intensive topical steroids with a presumed diagnosis of severe herpes zoster uveitis. RESULTS: Clinical findings improved dramatically within several days. Typical sectorial iris atrophy with pupillary sphincter dysfunction and complete loss of corneal sensation developed after the resolution of intraocular inflammation. CONCLUSION: Herpes zoster should be considered in patients with uveitis and hyphema even in the absence of typical skin rash.

Objective To describe the presentation and the clinical course of a patient with consecutive central sterile corneal perforations associated with common variable immunodeficiency. Design Case report. Methods Multiple corneal cultures and scrapings were performed in an effort to identify an infectious cause and all were negative. Corneal biopsy did not demonstrate any evidence of micro-organisms. An extended investigation failed to uncover a collagen vascular cause or atopy. Results Progressive sterile stromal thinning with intact epithelium in the left eye proceeded to perforation despite topical treatment, and cyanoacrylate gluing was performed. However, a secondary Haemophilus influenza endophthalmitis developed, and the eye was eventually lost. The fellow eye proceeded along the same clinical course with sterile stromal thinning. A lamellar patch graft was performed when the central ulceration progressed to a descemetocele. The eye remained quiet with 20/25 vision for 2 years, until the patient died from complications of a liver transplant. Conclusions Devastating central sterile corneal thinning leading to perforation may occur in patients with hypogammaglobulinemia. Clinical features and course suggest an autoimmune cause.

The calgranulins are a family of calcium- and zinc-binding proteins produced by neutrophils, monocytes, and other cells. Calgranulins are released during inflammatory responses and have antimicrobial activity. Recently, one of the calgranulins, human calgranulin C (CaGC), has been implicated as an important component of the host responses that limit the parasite burden during filarial nematode infections. The goal of this work was to test the hypothesis that human CaGC has biologic activity against filarial parasites. Brugia malayi microfilariae and adults were exposed in vitro to 0.75 to 100 nM recombinant human CaGC. Recombinant CaGC affected adult and larval parasites in a dose-dependent fashion. Microfilariae were more sensitive to the action of CaGC than were adult parasites. At high levels, CaGC was both macrofilariacidal and microfilariacidal. At lower levels, the percentage of parasites killed was dependent on the level of CaGC in the culture system. The larvae not killed had limited motility. The filariastatic effect of low-level CaGC was reversed when the CaGC was removed from the culture system. Immunohistochemical analysis demonstrated that human CaGC accumulated in the cells of the hypodermis-lateral chord of adult and larval parasites. The antifilarial activity of CaGC was not due to the sequestration of zinc. Thus, the cellular and molecular mechanisms that result in the production and release of CaGC in humans may play a key role in the regulation of filarial parasite numbers.

The authors have identified a corneal stromal protein (CO-Ag) that may be involved in the pathogenesis of Mooren's ulcer. The CO-Ag cDNA sequence is identical to that of human neutrophil calgranulin C (CaGC). This study sought to demonstrate expression of the CaGC gene in the human cornea and in corneal keratocytes after cytokine stimulation. In situ hybridization and immunohistochemistry were used to localize CaGC mRNA and protein in normal and diseased human corneas, including a specimen with Mooren's ulcer. Cultured bovine keratocytes were stimulated with IL-1 alpha or TNF-alpha, and reverse transcription polymerase chain reaction (RT-PCR) was performed to amplify CaGC cDNA from cytokine-stimulated keratocytes and unstimulated controls. Southern blotting verified the specificity of the RT-PCR amplification products. In situ hybridization detected human CaGC mRNA in the stroma of corneas with Fuchs' dystrophy, postinfection corneas, and a cornea with Mooren's ulcer. In cultured bovine keratocytes, peak levels of CaGC mRNA were reached 6 h after cytokine stimulation. Southern blots with an oligonucleotide probe specific for CaGC detected the RT-PCR products of expected sizes (273 bp) and confirmed that the amplified CO-Ag sequence was identical to that of CaGC. These studies are the first to demonstrate the presence of CaGC in the human cornea and the ability of stromal keratocytes to produce CaGC (CO-Ag). The up-regulation of CaGC gene expression by corneal keratocytes due to proinflammatory cytokines from trauma or inflammation may induce autoimmunity that ultimately results in Mooren's ulceration.

A host-parasite interaction is thought to be involved in the pathogenesis of Mooren's ulcer. We have identified a cornea-associated antigen (CO-Ag), which may be a target for the autoimmune process resulting in Mooren's ulcer. This study presents the cloning, expression, and identification of a cDNA encoding human CO-Ag.Reverse transcription-polymerase chain reaction (RT-PCR) was performed to amplify a cDNA encoding CO-Ag in the human cornea. The cDNA fragment was cloned into a prokaryotic expression vector and the resulting plasmid was transformed into DH5 E. coli cells. Autoantibody reactivity to the CO-Ag fusion protein in patient sera was tested by Western blots.A cDNA encoding human CO-Ag was amplified by RT-PCR. The entire mRNA coding region was 273 nucleotides in length, predicting a 91-amino acid protein with a molecular weight of 10,683 daltons. The cDNA sequence was identical to human neutrophil calgranulin C (CaGC). Human CO-Ag was expressed in E. coli carrying a plasmid in which the CO-Ag cDNA was under control of the E. coli trc promoter. The CO-Ag fusion protein, which comprised as much as 15% of the total bacterial protein, was purified to 90% homogeneity by affinity chromatography on an immobilized metal column. The recombinant CO-Ag protein produced was recognized by autoantibodies in the sera of 6 of 15 patients with Mooren's ulcer and none of 14 normal control sera by Western blots.CO-Ag is identical to calgranulin C, a neutrophil protein found on the surface of filarial nematodes. A host-parasite interaction may cause autoimmunity to CO-Ag (CaGC) in the cornea resulting in a Mooren's ulcer.

Basic fibroblast growth factor (bFGF) and FGF receptors have been localized to photoreceptors and retinal pigmented epithelium (RPE), but the function of bFGF in adult retina and RPE is unknown. Exogenous bFGF has a neuroprotective effect in retina and brain and its expression is increased in some neurons in response to cytokines or stress. In this study, we investigated the effect of light, other types of stress, neurotrophic factors, and cytokines on bFGF levels in cultured human RPE. Some agents that protect photoreceptors from the damaging effects of constant light, including brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor, and interleukin-1β, increase bFGF mRNA levels in RPE cells. Intense light and exposure to oxidizing agents also increase bFGF mRNA levels in RPE cells and cycloheximide blocks the increase. An increase in bFGF protein levels was demonstrated by ELISA in RPE cell supernatants after incubation with BDNF or exposure to intense light or oxidizing agents. These data indicate that bFGF is modulated in RPE cells by stress and by agents that provide protection from stress and support the hypothesis that bFGF functions as a survival factor in the outer retina.

Purpose: To evaluate comprehensively the magnitude of suspected risk factors for corneal graft failure from any cause, failure from rejection, and immunologic reaction in patients at high risk for graft failure after corneal transplantation. Methods: The records of the 457 participants in the Collaborative Corneal Transplantation Studies were reviewed. All participants had at least two quadrants of stromal vascularization and/or a history or previous graft rejection. Patients were followed for 2 to 5 years. Characteristics of the patient, study eye, donor, donor-recipient histocompatibility, and surgical procedure were examined for their association with the graft outcomes of failure from any cause, rejection failure, and immunologic reaction. Multivariate survival analysis techniques were used to estimate rates of graft outcome events and to estimate the magnitude of risk factors. Results: Many apparent risk factors did not maintain their association with graft outcomes after adjustment for other risk factors. Young recipient age, the number of previous grafts, history of previous anterior segment surgery, preoperative glaucoma, quadrants of anterior synechiae, quadrants of stromal vessels, a primary diagnosis of chemical burn, and blood group ABO incompatibility were among the strongest risk factors identified for graft failure. Donor and corneal preservation characteristics had little influence on graft outcome. Conclusions: Risk of graft failure varies substantially, even within a high-risk population. The number of risk factors present should be considered by the patient and surgeon when contemplating transplantation and planning follow-up.

An autosomal dominant syndrome of anterior polar cataract and endothelial dystrophy was first described in a large Swedish family in 1951.1 The affected individuals developed anterior polar cataracts in early childhood and corneal guttae as early as age 10, with corneal disease progressing with age. The severity of the disease varied between family members: while the majority of affected individuals developed both corneal guttae and cataracts, one individual had guttae and no cataract. A similar disease phenotype was later reported in an American family of Scandinavian descent. Through at least five generations, this family inherited autosomal dominant anterior polar cataract with corneal guttae.2 Histologic examination of the cornea of the affected proband revealed epithelial edema, normal stroma, and thickening of the Descemet membrane with focal excrescences. A third instance of a dominant syndrome of cataract and corneal dystrophy was reported in a large Northern Irish family in 2003.3 Similar to the previous reports, affected members of this family developed anterior polar cataract in childhood; however, in contrast to previously described cases, the corneal dystrophy in this family was described as keratoconus rather than as cornea guttata. We have described EDICT syndrome, an autosomal dominant syndromal anterior segment dysgenesis characterized by endothelial dystrophy, iris hypoplasia, congenital cataract, and stromal thinning.4,5 The locus for keratoconus with cataract was mapped to a 5.5-Mb region within the previous linkage interval for EDICT syndrome, suggesting a possible common causative mutation.3,4,6 The common linkage interval harbors 75 annotated genes and 4 microRNAs.7,8 MicroRNAs are short RNA molecules that bind to messenger RNA, downregulating gene expression by inhibiting translation and triggering degradation of mRNA by the Argonaute protein.9–12 MicroRNA is first produced as primary microRNA, which is cleaved in successive steps by the RNase III enzymes Drosha and Dicer to produce the mature microRNA that is incorporated into the RNA-induced silencing complex (RISC).13,14 The region from bases 2 to 7 of the mature microRNA, known as the seed region, is especially important for recognition of target mRNA and proper microRNA regulation of protein expression.15 Indeed, a mutation in the seed region of miR-96 has been implicated in hereditary hearing loss.16 We report a causal mutation for EDICT syndrome found in the seed region of miR-184.

Fuchs corneal dystrophy (FCD) is a genetic disorder of the corneal endothelium and is the most common cause of corneal transplantation in the United States. Previously, we mapped a late-onset FCD locus, FCD2, on chromosome 18q. Here, we present next-generation sequencing of all coding exons in the FCD2 critical interval in a multigenerational pedigree in which FCD segregates as an autosomal-dominant trait. We identified a missense change in LOXHD1, a gene causing progressive hearing loss in humans, as the sole variant capable of explaining the phenotype in this pedigree. We observed LOXHD1 mRNA in cultured human corneal endothelial cells, whereas antibody staining of both human and mouse corneas showed staining in the corneal epithelium and endothelium. Corneal sections of the original proband were stained for LOXHD1 and demonstrated a distinct increase in antibody punctate staining in the endothelium and Descemet membrane; punctate staining was absent from both normal corneas and FCD corneas negative for causal LOXHD1 mutations. Subsequent interrogation of a cohort of >200 sporadic affected individuals identified another 15 heterozygous missense mutations that were absent from >800 control chromosomes. Furthermore, in silico analyses predicted that these mutations reside on the surface of the protein and are likely to affect the protein's interface and protein-protein interactions. Finally, expression of the familial LOXHD1 mutant allele as well as two sporadic mutations in cells revealed prominent cytoplasmic aggregates reminiscent of the corneal phenotype. All together, our data implicate rare alleles in LOXHD1 in the pathogenesis of FCD and highlight how different mutations in the same locus can potentially produce diverse phenotypes.

Purpose To investigate the clinical and genetic features of late-onset Fuchs corneal dystrophy (FCD) on Tangier, an island in the Chesapeake Bay with an isolated population of approximately 500 individuals. Design Observational, cross-sectional study. Methods A total of 156 individuals born to inhabitants of Tangier Island volunteered to undergo ophthalmic evaluation. Medical history was ascertained prior to examination. All participants underwent anterior segment examination with slit-lamp biomicroscopy. Retroillumination photographs were acquired from affected individuals and the disease severity was compared with individuals from large families ascertained previously. Genomic DNA samples were investigated for the presence of the recently identified risk allele rs613872, an intronic variant of TCF4 . Results Of the 148 examined individuals who were at least 30 years of age, 32 showed the classical symptoms of late-onset FCD (21.6%), providing a minimum prevalence of 11% among individuals over the age of 50 years. Severity was significantly lower compared to 51 cases from unlinked families, among individuals either 50 to 70 or above 70 years of age ( P = .05 and P = .01, respectively). Retroillumination photography analyses were suggestive of mild severity when compared with the disease phenotype associated with FCD1 - and FCD2 -linked families. The rs613872 variant was associated with a higher affectation rate ( P = .01), while the wild-type allele was correlated with a higher proportion of subclinical disease ( P = .01). Conclusions In this study population in Tangier, late-onset FCD manifests clinically with a mild phenotype and increased prevalence. The rs613872 variant correlates with increased affectation and a clinical disease phenotype.

Fuchs corneal dystrophy (FCD) is a heritable, progressive disease of the corneal endothelium and a leading cause of corneal transplantation in the United States.1,2 Generally, disease onset begins in the fifth decade of life and progresses slowly over the next two to three decades.2–4 Phenotypically, FCD is characterized by the presence of corneal guttae, histologically defined as drop-like excrescences of Descemet membrane, the collagen-rich basal lamina of the corneal endothelium.4,5 FCD is a genetically heterogeneous disorder that exhibits an autosomal dominant mode of inheritance with variable penetrance and expressivity. The rare form of early-onset FCD is causally associated with mutations in COL8A2, whereas the more common late-onset FCD has been localized to four loci—FCD1, FCD2, FCD3, and FCD4—on chromosomes 13, 18, 5, and 9, respectively.6–10 In addition, heterozygous loss of function mutations in SLC4A11 have been identified in sporadic and familial cases of late-onset FCD.11,12 Similarly, mutational analysis and subsequent functional evaluations have shown that missense changes in TCF8 lead to late-onset FCD, with evidence for genetic interaction between this locus and FCD4 that modifies the severity of the disorder.10 TCF8 encodes a zinc finger transcription factor that regulates gene expression by repressing or activating target genes.13,14 Sobrado et al.15 demonstrated recently that the expression of TCF8 is regulated by another transcription factor protein, TCF4, suggesting that TCF4 and TCF8 are elements of a common pathway relevant to the pathomechanism of late-onset FCD. TCF4 encodes a helix-loop-helix protein present in most eukaryotic organisms, with important roles in essential developmental processes.16–18 The TCF4 locus maps in the critical interval of FCD2 on chromosome 18q. Recently, an intronic TCF4 SNP, rs613872, was identified through a genome-wide study to be associated with late onset-FCD.19 Given this report and the implication of TCF8 in the pathogenicity of FCD, we investigated the role of TCF4 in the etiology of late-onset FCD.

Background: To investigate the indications, outcomes, and complications of N-butyl cyanoacrylate tissue adhesive for ocular clinical use. This tissue adhesive is under investigation by the Food and Drug Administration. Methods: N-butyl cyanoacrylate was used as an investigational device on 44 patients at the authors' institution over a 2-year period. The charts of these patients were reviewed. Results: The indications for glue application included corneal perforation (19 eyes), descemetoceles (9 eyes), leaking filtering blebs (6 eyes), stromal thinning (5 eyes), wound leaks (4 eyes), and exposure keratopathy (1 eye). A bandage contact lens was used over the dried tissue adhesive in 38 of the 44 eyes. Length of glue adherence ranged from 1 to 660 days (mean, 72 days). Outcome was penetrating keratoplasty (19 eyes), no further intervention (14 eyes), enucleation (4 eyes), surgical revision of a filter (2 eyes), scleral patch graft (1 eye), conjunctival transplant (1 eye), failed tarsorrhaphy (1 eye), suturing of wound (1 eye), and a lamellar graft (1 eye). Vision improved in 52% (23/44) of eyes. Conclusion: This tissue adhesive may soon be available to all ophthalmologists, and the authors' experience demonstrates that it is an effective method of temporary or permanent closure of an impending or frank perforation.

A 56-year-old man presented with acute loss of vision and tearing in his left eye. Slitlamp examination demonstrated peripheral corneal edema extending between the 2 and 6 o'clock positions as well as a perforation located inferiorly. The right eye was unremarkable. An emergent crescentic lamellar keratoplasty was performed. The patch graft remained clear during the 30-month follow-up, and visual acuity improved significantly. No changes occurred in the right eye. This case represents an unusual, unilateral corneal ectatic disorder, most likely pellucid marginal degeneration.

Fuchs endothelial corneal dystrophy (FECD) is a common, late-onset disorder of the corneal endothelium. Although progress has been made in understanding the genetic basis of FECD by studying large families in which the phenotype is transmitted in an autosomal dominant fashion, a recently reported genome-wide association study identified common alleles at a locus on chromosome 18 near TCF4 which confer susceptibility to FECD. Here, we report the findings of our independent validation study for TCF4 using the largest FECD dataset to date (450 FECD cases and 340 normal controls). Logistic regression with sex as a covariate was performed for three genetic models: dominant (DOM), additive (ADD), and recessive (REC). We found significant association with rs613872, the target marker reported by Baratz et al.(2010), for all three genetic models (DOM: P = 9.33×10(-35); ADD: P = 7.48×10(-30); REC: P = 5.27×10(-6)). To strengthen the association study, we also conducted a genome-wide linkage scan on 64 multiplex families, composed primarily of affected sibling pairs (ASPs), using both parametric and non-parametric two-point and multipoint analyses. The most significant linkage region localizes to chromosome 18 from 69.94cM to 85.29cM, with a peak multipoint HLOD = 2.5 at rs1145315 (75.58cM) under the DOM model, mapping 1.5 Mb proximal to rs613872. In summary, our study presents evidence to support the role of the intronic TCF4 single nucleotide polymorphism rs613872 in late-onset FECD through both association and linkage studies.

Homozygous mutations in the Borate Cotransporter SLC4A11 cause two early-onset corneal dystrophies: congenital hereditary endothelial dystrophy (CHED) and Harboyan syndrome. More recently, four sporadic patients with late-onset Fuchs corneal dystrophy (FCD), a common age-related disorder, were also reported to harbor heterozygous mutations at this locus. We therefore tested the hypothesis that SLC4A11 contributes to FCD and asked whether mutations in SLC4A11 are responsible for familial cases of late-onset FCD. We sequenced SLC4A11 in 192 sporadic and small nuclear late-onset FCD families and found seven heterozygous missense novel variations that were absent from ethnically matched controls. Familial data available for one of these mutations showed segregation under a dominant model in a three-generational family. In silico analyses suggested that most of these substitutions are intolerant, whereas biochemical studies of the mutant protein indicated that these alleles impact the localization and/or posttranslational modification of the protein. These results suggest that heterozygous mutations in SLC4A11 are modest contributors to the pathogenesis of adult FCD, suggesting a causality continuum between FCD and CHED. Taken together with a recent model between FCD and yet another early onset corneal dystrophy, PPCD, our data suggest a shared pathomechanism and genetic overlap across several corneal dystrophies.