Ula V. Jurkunas

Topical Bevacizumab in the Treatment of Corneal Neovascularization Results of a Prospective, Open-Label, Noncomparative Study

OBJECTIVE To study the safety and efficacy of topical bevacizumab in the treatment of corneal neovascularization (NV). DESIGN In a prospective, open-label, noncomparative study, 10 eyes from 10 patients with stable corneal NV were treated with topical bevacizumab, 1.0%, for 3 weeks and followed up for up to 24 weeks. MAIN OUTCOME MEASURES The primary safety variables were the occurrence of ocular and systemic adverse events throughout the course of the study. The primary efficacy variables were neovascular area, the area of the corneal vessels themselves; vessel caliber, the mean diameter of the corneal vessels; and invasion area, the fraction of the total corneal area covered by the vessels. RESULTS From baseline visit to the last follow-up visit, mean reductions were 47.1% (standard deviation [SD], 36.7%) for neovascular area, 54.1% (SD, 28.1%) for vessel caliber, and 12.2% (SD, 42.0%) for invasion area. The decreases in neovascular area and vessel caliber were statistically significant (P= .001 and P< .001, respectively). However, changes in invasion area did not achieve statistical significance (P= .19). Visual acuity and central corneal thickness showed no significant changes. Topical bevacizumab was well tolerated with no adverse events. CONCLUSIONS Short-term topical bevacizumab therapy reduces the severity of corneal NV without local or systemic adverse effects. APPLICATION TO CLINICAL PRACTICE Topical bevacizumab provides an alternative therapy in the treatment of stable corneal NV. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00559936.

Fuchs Endothelial Corneal Dystrophy

Fuchs endothelial corneal dystrophy (FECD) is characterized by progressive loss of corneal endothelial cells, thickening of Descements membrane and deposition of extracellular matrix in the form of guttae. When the number of endothelial cells becomes critically low, the cornea swells and causes loss of vision. The clinical course of FECD usually spans 10-20 years. Corneal transplantation is currently the only modality used to restore vision. Over the last several decades genetic studies have detected several genes, as well as areas of chromosomal loci associated with the disease. Proteomic studies have given rise to several hypotheses regarding the pathogenesis of FECD. This review expands upon the recent findings from proteomic and genetic studies and builds upon recent advances in understanding the causes of this common corneal disorder.

Mutations in LOXHD1, a recessive-deafness locus, cause dominant late-onset Fuchs corneal dystrophy.

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 proteins 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.

Fungal keratitis: changing pathogens and risk factors.

Purpose: To describe changes in demographics and pathogens for fungal keratitis cases diagnosed at the Massachusetts Eye and Ear Infirmary. Methods: Patient demographics, clinical and laboratory findings, treatment and outcomes of 46 cases of culture-proven fungal keratitis diagnosed from January 2004 through November 2007 were compared with 23 cases of fungal keratitis previously collected over a similar period from January 1999 through November 2002. Results: During 2004-2007, the rate of fungal keratitis was 1.0 cases per month, an increase from the baseline rate of 0.5 cases per month during 1999-2002. The proportion of cases caused by filamentous fungi increased from 30% (1999-2002) to 65% (2004-2007) (P = 0.01). Soft contact lens wear accounted for 41% of fungal keratitis cases in 2004-2007, as compared with 17% in 1999-2002. The majority of patients (70%) received oral antifungal treatment in addition to topical amphotericin B and natamycin. Seventeen patients (40%) required therapeutic keratoplasty. Patients with a history of corneal transplant had the highest rate of therapeutic keratoplasties (67%) and had the poorest visual outcome (40% counting fingers or less). In the contact lens group, 94% of patients maintained vision of at least 20/40 and only 12% required surgery to control the infection. Conclusions: There has been an increase in fungal keratitis in the Boston area and a change in the causative pathogens and risk factors for infection. Filamentous fungi now account for the majority of fungal keratitis cases, whereas yeasts were the predominant pathogen in the past. Soft contact lens wear is currently the most common risk factor for development of fungal keratitis.

Topical interleukin 1 receptor antagonist for treatment of dry eye disease: a randomized clinical trial.

IMPORTANCE The immunopathogenic mechanisms of dry eye disease (DED), one of the most common ophthalmic conditions, is incompletely understood. Data from this prospective, double-masked, randomized trial demonstrate that targeting interleukin 1 (IL-1) by topical application of an IL-1 antagonist is efficacious in significantly reducing DED-related patient symptoms and corneal epitheliopathy. OBJECTIVE To evaluate the safety and efficacy of treatment with the topical IL-1 receptor antagonist anakinra (Kineret; Amgen Inc) in patients having DED associated with meibomian gland dysfunction. DESIGN AND SETTING Prospective phase 1/2, randomized, double-masked, vehicle-controlled clinical trial. PARTICIPANTS Seventy-five patients with refractory DED. INTERVENTIONS Participants were randomized to receive treatment with topical anakinra, 2.5% (n = 30), anakinra, 5% (n = 15), or vehicle (1% carboxymethylcellulose) (n = 30) 3 times daily for 12 weeks. MAIN OUTCOMES AND MEASURES Primary outcomes were corneal fluorescein staining (CFS), complete bilateral CFS clearance, dry eye-related symptoms as measured by the Ocular Surface Disease Index, tear film breakup time, and meibomian gland secretion quality. RESULTS Topical anakinra was well tolerated compared with vehicle, with no reports of serious adverse reactions attributable to the therapy. After 12 weeks of therapy, participants treated with anakinra, 2.5%, achieved a 46% reduction in their mean CFS score (P = .12 compared with vehicle and P < .001 compared with baseline); participants treated with anakinra, 5%, achieved a 17% reduction in their mean CFS score (P = .88 compared with vehicle and P = .33 compared with baseline); and patients treated with vehicle achieved a 19% reduction in their mean CFS score (P = .11). Complete bilateral CFS clearance was noted in 8 of 28 patients (29%) treated with anakinra, 2.5%, vs in 2 of 29 patients (7%) treated with vehicle (P = .03). By week 12, treatment with anakinra, 2.5%, and treatment with anakinra, 5%, led to significant reductions in symptoms of 30% and 35%, respectively (P = .02 and P = .01, respectively, compared with vehicle); treatment with vehicle led to a 5% reduction in symptoms. CONCLUSIONS AND RELEVANCE Treatment with topical anakinra, 2.5%, for 12 weeks was safe and significantly reduced symptoms and corneal epitheliopathy in patients with DED. These data suggest that the use of an IL-1 antagonist may have a role as a novel therapeutic option for patients with DED. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00681109.

p53-regulated increase in oxidative-stress--induced apoptosis in Fuchs endothelial corneal dystrophy: a native tissue model.

PURPOSE This study compared susceptibility of Fuchs endothelial corneal dystrophy (FECD) and normal corneal endothelial cells (CECs) to oxidative stress, and studied the mechanism of oxidative-stress-induced apoptosis in FECD-affected endothelium. METHODS For in vitro studies, immortalized normal and FECD human corneal endothelial cell lines (HCECi and FECDi, respectively) were exposed to tert-butyl hydroperoxide (tBHP). Apoptotic cell populations were distinguished using flow cytometry. Reactive oxygen species production was measured by a horseradish peroxidase assay. For ex vivo studies, CECs were exposed to tBHP. Oxidative DNA damage and apoptosis were assessed by anti-8-hydroxydeoxyguanosine antibody and TUNEL assay, respectively. p53 and phospho-p53 levels were assessed by Western blot and immunohistochemistry. RESULTS Flow cytometry revealed a higher rate of apoptosis in FECDi than that in HCECi after exposure to 0.5 mM (P=0.010) and 1.0 mM tBHP (P=0.041). Further analysis showed increased production of H2O2 by FECDi than that by HCECi. Oxidative DNA damage increased in both normal and FECD CECs after exposure to 0.5 mM tBHP (P=0.031 and 0.022, respectively), leading to a 21% increase in TUNEL-positive CECs in FECD (P=0.015) but no change in normal. Baseline p53 expression was twofold higher in FECD than that in normal endothelium (P=0.002). Immunofluorescence revealed an increase in p53 and phospho-p53 levels in FECD compared with that in normal endothelium. CONCLUSIONS FECD CECs are more susceptible to oxidative DNA damage and oxidative-stress-induced apoptosis than normal. Increased activation of p53 in FECD suggests that it mediates cell death in susceptible CECs. The authors conclude that p53 plays a critical role in complex mechanisms regulating oxidative-stress-induced apoptosis in FECD.

Limbal stem cell deficiency and corneal neovascularization.

The corneal limbus harbors corneal epithelial stem cells and contributes to the unique microenvironment of the stem cell niche. Corneal conditions, such as infections, tumors, immunological disorders, trauma, and chemical burns, often lead to the deficiency of the corneal stem cells, and subsequent vision loss. One key feature of limbal stem cell deficiency is corneal neovascularization. There is a delicate balance between pro-angiogenic and anti-angiogenic factors that, in a normal cornea, maintain an avascular state. A pro-angiogenic shift in this balance can occur due to various mechanisms, such as inflammation, gene mutations, physical breach in the limbal barrier, and decreased production of anti-angiogenic molecules. Currently available treatment options for limbal stem cell deficiency include allogeneic and autologous limbal transplants, and more recently, transplantation of alternative sources of epithelium, such as cultivated corneal and oral mucosal stem cells. Further studies are needed to investigate the combination of limbal and stem cell transplantation and concurrent anti-angiogenic therapy.

The culture and transplantation of human limbal stem cells

The cornea is the clear front of the eye and its surface is composed of an epithelium. This is renewed by stem cells located at the limbus, which encircles the periphery of the cornea. These limbal stem cells become lost or deficient in the blinding disease of limbal stem cell deficiency. In this review article, we discuss the historical perspective in managing limbal stem cell deficiency as well as describing the more contemporary treatment options, and in particular the culture and transplantation of human limbal stem cells. This treatment was first proposed 13 years ago and many case series have been presented to date showing promising outcomes of this technique. However, challenges still remain in treating the debilitating disease of limbal stem cell deficiency. Here we discuss some of the questions, which remain to be answered in this field. J. Cell. Physiol. 225: 15–19, 2010.

Comparative Analysis of Human-Derived Feeder Layers with 3T3 Fibroblasts for the Ex Vivo Expansion of Human Limbal and Oral Epithelium

Corneal transplantation with cultivated limbal or oral epithelium is a feasible treatment option for limbal stem cell deficiency (LSCD). Currently utilized co-culture of stem cells with murine 3T3 feeder layer renders the epithelial constructs as xenografts. To overcome the potential risks involved with xenotransplantation, we investigated the use of human-derived feeder layers for the ex vivo expansion of epithelial (stem) cells. Human limbal and oral epithelium was co-cultured with mouse 3T3 fibroblasts, human dermal fibroblasts (DF), human mesenchymal stem cells (MSC), and with no feeder cells (NF). Cell morphology was monitored with phase-contrast microscopy, and stem cell characteristics were assessed by immunohistochemistry, real-time PCR for p63 and ABCG2, (stem cell markers), and by colony-forming efficiency (CFE) assay. Immunohistochemical analysis detected positive staining for CK3 (cornea specific marker) and Iβ1 and p63 (putative stem cell markers) in all culture conditions. The level of Iβ1 and p63 was significantly higher in both limbal and oral cells cultured on the 3T3 feeder, as compared to the MSC or NF group (p < 0.01). This level was comparable to the cells cultured on DF. Expression of p63 and ABCG2 in limbal and oral epithelial cells in the 3T3 and DF groups was significantly higher than that in the MSC or NF group (p < 0.01). No statistical difference was detected between 3T3 and DF groups. The CFE of both limbal and oral cells co-cultured on 3T3 fibroblasts was comparable to cells grown on DF, and was significantly higher than that of cells co-cultured with MSC or NF (p < 0.01). Epithelial cells grown on a DF feeder layer maintained a stem cell-like phenotype, comparable to cells grown on a 3T3 feeder layer. In conclusion, DF provides a promising substitute for 3T3 feeder cells during cultivation of xenobiotic-free corneal equivalents.

Decline in DJ-1 and Decreased Nuclear Translocation of Nrf2 in Fuchs Endothelial Corneal Dystrophy

PURPOSE This study sought to determine factors involved in nuclear factor erythroid 2-related factor 2 (Nrf2) regulation and their response to oxidative stress in Fuchs endothelial corneal dystrophy (FECD) and normal corneal endothelial cells (CECs). METHODS FECD corneal buttons were obtained from transplantations and normal human corneas from tissue banks. Oxidative stress was induced by tert-butyl hydroperoxide (tBHP). Protein and mRNA levels of Nrf2, DJ-1, p53, and Kelch-like ECH-associated protein1 (Keap1) were investigated using Western blotting and real-time PCR. Immunoprecipitation was used to detect levels of oxidized DJ-1 protein and Cullin 3- (Cul3)-regulated degradation of DJ-1 in immortalized FECD (FECDi) and normal CEC (HCECi) cell lines. Nrf2 subcellular localization was assessed by immunocytochemistry. RESULTS Nrf2 protein stabilizer, DJ-1, decreased significantly in FECD CECs compared with normal, whereas Nrf2 protein repressor, Keap1, was unchanged at baseline but increased under oxidative stress. Under oxidative stress, normal CECs upregulated DJ-1 protein synthesis, whereas FECD CECs did not. DJ-1 decline correlated with increased DJ-1 oxidative modification and carbonylation in FECDi as compared with HCECi. Increased labeling of immunoprecipitated DJ-1 protein with anti-Cul3 antibody indicated enhanced DJ-1 degradation in FECDi as compared with HCECi. Following tBHP treatment, Nrf2 translocated from cytoplasm to nuclei in normal CECs, whereas Nrf2 nuclear localization was not observed in FECD. CONCLUSIONS Decreased levels of DJ-1 in FECD at baseline and under oxidative stress correlate with impaired Nrf2 nuclear translocation and heightened cell susceptibility to apoptosis. Targeting the DJ-1/Nrf2 axis could yield a mechanism to slow CEC degeneration in FECD.