E2-2 protein and Fuchs's corneal dystrophy.

BACKGROUND: Fuchs's corneal dystrophy (FCD) is a leading cause of corneal transplantation and affects 5% of persons in the United States who are over the age of 40 years. Clinically visible deposits called guttae develop under the corneal endothelium in patients with FCD. A loss of endothelial cells and deposition of an abnormal extracellular matrix are observed microscopically. In advanced disease, the cornea swells and becomes cloudy because the remaining endothelial cells are not sufficient to keep the cornea dehydrated and clear. Although rare genetic variation that contributes to both early-onset and typical late-onset forms of FCD has been identified, to our knowledge, no common variants have been reported. METHODS: We performed a genomewide association study and replicated the most significant observations in a second, independent group of subjects. RESULTS: Alleles in the transcription factor 4 gene (TCF4), encoding a member of the E-protein family (E2-2), were associated with typical FCD (P=2.3x10(-26)). The association increased the odds of having FCD by a factor of 30 for persons with two copies of the disease variants (homozygotes) and discriminated between case subjects and control subjects with about 76% accuracy. At least two regions of the TCF4 locus were associated independently with FCD. Alleles in the gene encoding protein tyrosine phosphatase receptor type G (PTPRG) were associated with FCD (P=4.0x10(-7)), but the association did not reach genomewide significance. CONCLUSIONS: Genetic variation in TCF4 contributes to the development of FCD. (Funded by the National Eye Institute and others.)

Genetic control of the alternative pathway of complement in humans and age-related macular degeneration.

Activation of the alternative pathway of complement is implicated in common neurodegenerative diseases including age-related macular degeneration (AMD). We explored the impact of common variation in genes encoding proteins of the alternative pathway on complement activation in human blood and in AMD. Genetic variation across the genes encoding complement factor H (CFH), factor B (CFB) and component 3 (C3) was determined. The influence of common haplotypes defining transcriptional and translational units on complement activation in blood was determined in a quantitative genomic association study. Individual haplotypes in CFH and CFB were associated with distinct and novel effects on plasma levels of precursors, regulators and activation products of the alternative pathway of complement in human blood. Further, genetic variation in CFH thought to influence cell surface regulation of complement did not alter plasma complement levels in human blood. Plasma markers of chronic activation (split-products Ba and C3d) and an activating enzyme (factor D) were elevated in AMD subjects. Most of the elevation in AMD was accounted for by the genetic variation controlling complement activation in human blood. Activation of the alternative pathway of complement in blood is under genetic control and increases with age. The genetic variation associated with increased activation of complement in human blood also increased the risk of AMD. Our data are consistent with a disease model in which genetic variation in the complement system increases the risk of AMD by a combination of systemic complement activation and abnormal regulation of complement activation in local tissues.

Comparison of macular function and visual fields after membrane blue or infracyanine green staining in vitreoretinal surgery.

BACKGROUND: To compare possible toxic effects of membrane blue and infracyanine green used as vital stains in macular surgery. Vital stains are used in vitreoretinal surgery to perform peeling of the internal limiting membrane and idiopathic epiretinal membrane. There are many controversial studies about their toxicity, safety, and their effects on the retinal pigment epithelium and the neuroretinal elements. To compare possible toxicities of the two vital stains membrane blue and infracyanine green in vivo, we conducted a prospective, randomized, clinical trial. METHODS: A prospective, randomized clinical trial including 30 eyes of 30 patients with either full-thickness macular hole or idiopathic epiretinal membrane were included and randomized 1:1 to receive either membrane blue or infracyanine green during vitreoretinal surgery. Complete ophthalmic examinations, including optical coherence tomography and peripheral visual field were performed preoperatively, and 1, 3, and 6 months postoperatively in our clinic. The main outcome measure was the peripheral visual field. Data was analysed with Student's t-test and Pearson's correlation coefficient. RESULTS: Three months after surgery there was a significant difference in increase in visual field in the superior region in favor of the membrane blue group (p = 0.021). Eight eyes (53%) of the infracyanine group had a decrease in temporal visual fields of at least 5 degrees . CONCLUSION: Although there was a significant difference in visual fields between the groups after 3 months in the superior region, there were no more significant differences between the two groups after 6 months. However, due to the decrease in the temporal visual field in some eyes, we conclude that membrane blue is less toxic.

Effect of work-related ultraviolet exposure and ophthalmic changes in Austrian farmers: the SVB-UV study.

BACKGROUND: Epidemiological screening to examine possible ultraviolet-induced ocular changes and pathologies in Austrian farmers. METHODS: The study was performed on behalf of the Austrian farmer insurance (Sozialversicherungsanstalt der Bauern). Randomly selected farmers and office workers as controls, both at the age of 35-55 years, underwent ophthalmic screening examinations. All subjects underwent complete ophthalmic examinations by slit lamp examination and Schirmer's test 1. A survey, regarding personal habits in the sun, was also conducted. RESULTS: Three hundred and ninety-two subjects underwent ophthalmic examinations of whom 297 were farmers and 95 were controls. Due to the survey, 89.7% of the farmers claimed to protect themselves from the sun during work. From these subjects, 83.7% wear a head protection, 71.0% wear sunglasses, and 54.4% usually work in the shade. There were significant differences in lid (p = 0.021) and conjunctival pathologies (p < 0.0001) between farmers and controls. CONCLUSION: Austrian farmers are at a higher risk for developing lid and conjunctival tumours which require treatment at some point. We believe that the study group was too young to show significant differences within the lens and the posterior pole. A 5-year follow-up is planned.

Circulating angiopoietic cells and diabetic retinopathy in type 2 diabetes mellitus, with or without macrovascular disease.

PURPOSE: To investigate different types of circulating angiopoietic cells, such as vasculogenic circulating progenitor cells (CPCs), endothelial progenitor cells (EPCs), and mature EPCs (matEPCs) in patients with type 2 diabetes mellitus (T2DM), with or without diabetic retinopathy (DR) and with or without macrovascular disease (MVD). METHODS: One hundred twenty-six patients with T2DM-66 with MVD and 60 without MVD-were enrolled in a case-control study. MVD comprised coronary heart disease, peripheral arterial disease, stroke, or various combinations of those conditions. By a modified Early Treatment of Diabetic Retinopathy Study (ETDRS) classification, 55 patients were classified without DR (CO), 19 with mild nonproliferative DR (mNPDR), 16 with moderate-severe NPDR (msNPDR), 19 with early proliferative diabetic retinopathy (ePDR), and 17 with high-risk PDR (hrPDR). CPCs (CD34/CD133), EPCs (CD34/CD133/CD30), and matEPCs (CD34/CD133/CD309/CD31) were enumerated by flow cytometry. RESULTS: Patients with MVD CPCs, EPCs, and matEPCs showed a significant, stepwise decline with advancing stages of retinopathy. In contrast, in the patients without MVD, EPCs and matEPCs reached up to 56% of CPCs and 37% of EPCs. On the other hand, the percentage of EPCs and matEPCs was reduced to 5% of CPCs and EPCs each in MVD patients. Thus, the percentage of EPCs and matEPCs in comparison with that of CPCs and EPCs represented an 11- and 7-fold difference. CONCLUSIONS: The circulating angiopoietic CPCs, EPCs, and matEPCs in T2DM patients with DR had a different regulations, with increasing relative differences occurring in proliferative DR, apparently depending on the macrovascular comorbidities. Patients with MVD showed a strong retinopathy-stage-dependent depletion of all angiopoietic cells.

Comparing treatment of neovascular age-related macular degeneration with sequential intravitreal Avastin and Macugen versus intravitreal mono-therapy--a pilot study.

PURPOSE: To examine if the sequential treatment of Avastin and Macugen is safe and more efficient than the mono-therapies in a prospective randomized masked pilot study. MATERIALS AND METHODS: Subjects with exudative age-related macular degeneration were randomized to receive three intravitreal injections of either 1 mg of Avastin, 0.3 mg Macugen, or first 1 mg Avastin followed by retreatment of 0.3 mg Macugen. Follow-up examinations were performed after 1, 6, 12 weeks, and 6 months. RESULTS: Forty-eight subjects were included (13:18:17). Avastin resulted in lasting significant changes in visual acuity at 6 weeks, increase in contrast sensitivity at 6 weeks, and a significant decrease in macular thickness after 6 and 12 weeks. Macugen showed a significant decrease in retinal thickness after 6 weeks, but a significant decrease in visual acuity after 6 months, and a significant decrease in contrast sensitivity after 12 weeks and 6 months. The sequential treatment showed a decrease in retinal thickness after 1 and 12 weeks. CONCLUSION: Avastin alone is more effective in increasing visual acuity and contrast sensitivity and decreasing retinal thickness, than Macugen or the sequential treatment. We conclude that the sequential treatment of Avastin with Macugen is safe, but the single treatment of Avastin is more efficient.

Daytime levels of melatonin in patients with age-related macular degeneration.

PURPOSE: Melatonin (N-acetyl-5-methoxytryptamine) (MT) is a hormone that acts as an antioxidant. It is produced by the pineal gland and within the retina; its release is blocked by light entering the eye. We examined whether MT daytime levels differ between pseudophakic patients with age-related macular degeneration (ARMD) and pseudophakic subjects without any ocular pathology of the same age. METHODS: A prospective, cross-sectional, observational study was performed. Pseudophakic patients of the same age group were included. Patients underwent complete ophthalmic examinations and blood sampling between 08:00 and 10:00 hr. MT daytime value in the serum was the main outcome measure. RESULTS: Sixty-nine pseudophakic patients were included. Fifty patients with exudative and non-exudative ARMD were in the study group while 19 patients were controls. Patients with ARMD had significantly higher daytime levels of MT (P = 0.003). There were significant differences in MT daytime levels between the exudative and non-exudative forms (P = 0.009). MT values also correlated with the best-corrected visual acuity (r = -0.285, P = 0.019). CONCLUSION: These data indicate that pseudophakic patients with ARMD produce more MT during the day compared to pseudophakic subjects without ARMD. This may be caused by the reduced visual acuity in patients with ARMD, whereby less light reaches the photoreceptors, allowing MT secretion to continue during the day. Because MT also acts as an antioxidant and daytime levels are higher in patients with ARMD, these results might be interpreted as a rescue factor.

Correlation of different circulating endothelial progenitor cells to stages of diabetic retinopathy: first in vivo data.

PURPOSE: To investigate vasculogenic circulating progenitor cells (CPCs), endothelial progenitor cells (EPCs), and mature EPCs in patients with type 1 diabetes mellitus (T1DM) with or without diabetic retinopathy (DR). METHODS: A case-control study comparing 90 patients with T1DM with and without DR was performed. Patients were studied and staged for retinopathy according to the Early Treatment of Diabetic Retinopathy Study (ETDRS) classification. Ninety patients were included: 30 without DR (control [CO]), 30 with mild nonproliferative DR (mNPDR), 10 with moderate-severe NPDR (msNPDR), 10 with mild-moderate proliferative diabetic retinopathy (mmPDR), and 10 with high-risk PDR (hrPDR). CPCs (CD34/CD133), EPCs (CD34/CD133/CD309), and mature EPCs (CD34/CD133/CD309/CD31) were enumerated by flow cytometry. RESULTS: EPCs were reduced in mNPDR (114 +/- 66; P < 0.001) and msNPDR (77 +/- 40; P = 0.042) compared with CO (244 +/- 115). In contrast, EPCs were unchanged in mmPDR (248 +/- 155) compared with CO. Strikingly, EPCs were augmented in hrPDR (389 +/- 124) compared with all other stages. Numbers of undifferentiated progenitor cells (CPCs) did not differ among CO, mmPDR, and hrPDR. Augmentation (3x) of mature EPCs in hrPDR (325 +/- 118; P < 0.001) compared with CO (100 +/- 49) but against all other stages of DR was observed. The percentage of mature EPCs/EPCs was augmented in an ETDRS classification-dependent manner. CONCLUSIONS: In patients with T1DM with DR, EPCs undergo stage-related regulation. In nonproliferative retinopathy, a reduction of EPCs was observed, and in proliferative retinopathy, a dramatic increase of mature EPCs was observed.

Contribution of copy number variation in the regulation of complement activation locus to development of age-related macular degeneration.

PURPOSE: To develop an assay for determining the number of copies of the genes encoding complement factor H related 3 (CFHR3) and 1 (CFHR1) and determine the contribution of copy number variation (CNV) at CFHR3 and CFHR1 to the development of age-related macular degeneration (AMD). METHODS: A multiplex ligation-dependent probe amplification (MLPA) assay was developed to quantify the number of copies of CFHR3 and CFHR1 in humans. Subjects with (n = 252) and without (n = 249) AMD were genotyped using the assay, and the impact on AMD risk was evaluated. RESULTS: The MLPA assay provided a consistent estimate of the number of copies of CFHR3 and CFHR1 in 500 of the 501 samples. Four different combinations of CNVs were observed with frequencies as follows: both CFHR3 and CFHR1 deletion (14%), CFHR3-only deletion (0.4%), CFHR1-only deletion (1.1%), and CFHR1 duplication (0.1%). Deletion of both copies of CFHR3 and CFHR1 decreased the odds of having AMD eightfold (95% CI 2-36) and always occurred on a protective haplotype, never on the risk haplotype tagged by the Y402H risk allele in CFH. The protection conferred by deletion of CFHR3 and CFHR1 could not be distinguished from the absence of the risk haplotype. CONCLUSIONS: Both deletions and duplications of genes in the regulation of complement activation locus segregated in Caucasians. Deletion of CFHR3 and CFHR1 protected against the development of AMD at least in part because the deletion tagged a protective haplotype and did not occur on the risk haplotype.