Systems biology-based analysis implicates a novel role for vitamin D metabolism in the pathogenesis of age-related macular degeneration.

Vitamin D has been shown to have anti-angiogenic properties and to play a protective role in several types of cancer, including breast, prostate and cutaneous melanoma. Similarly, vitamin D levels have been shown to be protective for risk of a number of conditions, including cardiovascular disease and chronic kidney disease, as well as numerous autoimmune disorders such as multiple sclerosis, inflammatory bowel diseases and type 1 diabetes mellitus. A study performed by Parekh et al. was the first to suggest a role for vitamin D in age-related macular degeneration (AMD) and showed a correlation between reduced serum vitamin D levels and risk for early AMD. Based on this study and the protective role of vitamin D in diseases with similar pathophysiology to AMD, we examined the role of vitamin D in a family-based cohort of 481 sibling pairs. Using extremely phenotypically discordant sibling pairs, initially we evaluated the association of neovascular AMD and vitamin D/sunlight-related epidemiological factors. After controlling for established AMD risk factors, including polymorphisms of the genes encoding complement factor H (CFH) and age-related maculopathy susceptibility 2/HtrA serine peptidase (ARMS2/HTRA1), and smoking history, we found that ultraviolet irradiance was protective for the development of neovascular AMD (p = 0.001). Although evaluation of serum vitamin D levels (25-hydroxyvitamin D [25(OH)D]) was higher in unaffected individuals than in their affected siblings, this finding did not reach statistical significance. Based on the relationship between ultraviolet irradiance and vitamin D production, we employed a candidate gene approach for evaluating common variation in key vitamin D pathway genes (the genes encoding the vitamin D receptor [VDR]; cytochrome P450, family 27, subfamily B, polypeptide 1 [CYP27B1]; cytochrome P450, family 24, subfamily A, polypeptide 1 [CYP24A1]; and CYP27A1) in this same family-based cohort. Initial findings were then validated and replicated in the extended family cohort, an unrelated case-control cohort from central Greece and a prospective nested case-control population from the Nurse's Health Study and Health Professionals Follow-Up Studies, which included patients with all subtypes of AMD for a total of 2,528 individuals. Single point variants in CYP24A1 (the gene encoding the catabolising enzyme of the vitamin D pathway) were demonstrated to influence AMD risk after controlling for smoking history, sex and age in all populations, both separately and, more importantly, in a meta-analysis. This is the first report demonstrating a genetic association between vitamin D metabolism and AMD risk. These findings were also supplemented with expression data from human donor eyes and human retinal cell lines. These data not only extend previous biological studies in the AMD field, but further emphasise common antecedents between several disorders with an inflammatory/immunogenic component such as cardiovascular disease, cancer and AMD.

European ST80 community-associated methicillin-resistant Staphylococcus aureus orbital cellulitis in a neonate.

BACKGROUND: Methicillin-resistant Staphylococcus aureus is a serious cause of morbidity and mortality in hospital environment, but also, lately, in the community. This case report is, to our knowledge, the first detailed description of a community-associated methicillin-resistant S. aureus ST80 orbital cellulitis in a previously healthy neonate. Possible predisposing factors of microbial acquisition and treatment selection are also discussed. CASE PRESENTATION: A 28-day-old Caucasian boy was referred to our hospital with the diagnosis of right orbital cellulitis. His symptoms included right eye proptosis, periocular edema and redness. Empirical therapy of intravenous daptomycin, rifampin and ceftriaxone was initiated. The culture of pus yielded a methicillin-resistant S. aureus isolate and the molecular analysis revealed that it was a Panton-Valentine leukocidine-positive ST80 strain. The combination antimicrobial therapy was continued for 42 days and the infection was successfully controlled. CONCLUSIONS: Clinicians should be aware that young infants, even without any predisposing condition, are susceptible to orbital cellulitis caused by community-associated methicillin-resistant S. aureus. Prompt initiation of the appropriate empirical therapy, according to the local epidemiology, should successfully address the infection, preventing ocular and systemic complications.

Perimetric and retinal nerve fiber layer findings in patients with Parkinson's disease.

BACKGROUND: Visual dysfunction is common in Parkinson's disease (PD). It remains, however, unknown whether it is related to structural alterations of the retina. The aim of this study is to compare visual field (VF) findings and circumpapillary retinal nerve fiber layer (RNFL) thickness in a series of PD patients and normal controls, in order to assess possible retinal anatomical changes and/or functional damage associated with PD. METHODS: PD patients and controls were recruited and underwent VF testing with static automated perimetry and RNFL examination with optical coherence tomography (OCT). Cognitive performance using Mini Mental State Examination (MMSE), PD staging using modified Hoehn and Yahr (H-Y) scale and duration of the disease was recorded in PD patients. RESULTS: One randomly selected eye from each of 24 patients and 24 age-matched controls was included. OCT RNFL thickness analysis revealed no difference in the inferior, superior, nasal or temporal sectors between the groups. The average peripapillary RNFL was also similar in the two groups. However, perimetric indices of generalized sensitivity loss (mean deviation) and localized scotomas (pattern standard deviation) were worse in patients with PD compared to controls (p < 0.01). 73% of eyes of PD patients had glaucomatous-like asymmetrical hemifield defects with abnormal Glaucoma Hemifield Test and various combinations of arcuate defects (n = 12), nasal steps (n = 11) and paracentral scotomas (n = 16). Bilateral defects were found in 14 patients (58%). No correlation was found between VF indices and MMSE or H-Y scores. CONCLUSION: PD patients may demonstrate glaucomatous-like perimetric defects even in the absence of decreased RNFL thickness.

Interleukin-1B and interleukin-1 receptor antagonist gene polymorphisms in Greek multiple sclerosis (MS) patients with bout-onset MS.

We investigated the association of specific polymorphisms of the interleukin IL-1b (AvaI -511 and TaqI +3,953) and IL-1 receptor antagonist (IL-1RN) (a variable number of tandem repeats; VNTR) genes with both the susceptibility to and the clinical characteristics in Greek multiple sclerosis (MS) patients cohort with bout-onset. Genotypes were determined from 351 patients with clinically definite MS and 375 age- and sex-matched healthy controls. Our results showed no significant differences in the distribution of these polymorphisms between MS patients and controls. Furthermore, stratification for clinical characteristics, such as age at disease onset, clinical course, sex, and severity did not provide significant differences between patients and controls. Together, our findings suggest that IL-1B and IL-1RN gene polymorphisms may not be relevant to the susceptibility to MS or the clinical characteristics of Greek MS patients.

Simple Single-Pass Technique for Ultrathin Descemet Stripping Automated Endothelial Keratoplasty: A Pilot Study.

PURPOSE: To assess intraoperative and postoperative graft thickness (GT) after donor deturgescence for ultrathin Descemet stripping automated endothelial keratoplasty and to evaluate visual outcomes, endothelial cell density, and patient satisfaction at 1 year. METHODS: Prospective interventional case series of patients with Fuchs endothelial dystrophy, Fuchs endothelial dystrophy and cataract, and pseudophakic bullous keratopathy (n = 12 grafts). The donor cornea was allowed to thin out by simple evaporation on an artificial anterior chamber, to the required precut thickness, before a single microkeratome pass. GT after microkeratome cut, at 1 week, 1, 3, 6, and 12, months was measured. Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity, Pelli-Robson contrast sensitivity, endothelial cell density, and score on the visual function questionnaire (VFQ-25) were assessed. RESULTS: Mean intraoperative postmicrokeratome cut GT was 78.9 ± 33.3 µm. Mean GT at 1 week, 1, 3, 6, and 12 months was 70.7, 70.9, 62.8, 66.5, and 58.9 µm, respectively. Mean initial donor corneal thickness was 647 ± 67 µm, and mean precut thickness was 526 ± 4.5 µm (mean thinning time: 17 min). Best-corrected visual acuity at 1 week, 1, 3, 6, and 12 months was 68.8, 76.9, 76.3, 76.9, and 78.6 letters with 9-letter gain at 12 months (P = 0.02). Mean endothelial cell loss at 3, 6, and 12 months was 36.8% ± 6.75%, 37.2% ± 8%, and 37.9% ± 9.75% loss, respectively. At 1 year, 83.3% of patients achieved ≥20/40 (6/12) and 66.7% of patients achieved ≥20/32 (6/9.5). VFQ-25 testing showed an improvement in the visual function. CONCLUSIONS: This pilot study demonstrates a simple graft deturgescence technique that reproducibly creates ultrathin grafts without donor wastage.

Ancestry of the Timorese: age-related macular degeneration associated genotype and allele sharing among human populations from throughout the world.

We observed that the third leading cause of blindness in the world, age-related macular degeneration (AMD), occurs at a very low documented frequency in a population-based cohort from Timor-Leste. Thus, we determined a complete catalog of the ancestry of the Timorese by analysis of whole exome chip data and haplogroup analysis of SNP genotypes determined by sequencing the Hypervariable I and II regions of the mitochondrial genome and 17 genotyped YSTR markers obtained from 535 individuals. We genotyped 20 previously reported AMD-associated SNPs in the Timorese to examine their allele frequencies compared to and between previously documented AMD cohorts of varying ethnicities. For those without AMD (average age > 55 years), genotype and allele frequencies were similar for most SNPs with a few exceptions. The major risk allele of HTRA1 rs11200638 (10q26) was at a significantly higher frequency in the Timorese, as well as 3 of the 5 protective CFH (1q32) SNPs (rs800292, rs2284664, and rs12066959). Additionally, the most commonly associated AMD-risk SNP, CFH rs1061170 (Y402H), was also seen at a much lower frequency in the Korean and Timorese populations than in the assessed Caucasian populations (C ~7 vs. ~40%, respectively). The difference in allele frequencies between the Timorese population and the other genotyped populations, along with the haplogroup analysis, also highlight the genetic diversity of the Timorese. Specifically, the most common ancestry groupings were Oceanic (Melanesian and Papuan) and Eastern Asian (specifically Han Chinese). The low prevalence of AMD in the Timorese population (2 of 535 randomly selected participants) may be due to the enrichment of protective alleles in this population at the 1q32 locus.

Plasma homocysteine and genetic variants of homocysteine metabolism enzymes in patients from central Greece with primary open-angle glaucoma and pseudoexfoliation glaucoma.

BACKGROUND: The purpose of this study was to investigate plasma homocysteine levels and polymorphisms in genes encoding enzymes in the metabolic pathway of homocysteine in association with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXFG). METHODS: A total of 156 glaucoma patients (76 with POAG and 80 with PXFG) and 135 controls matched for age and sex were enrolled in this study. Plasma homocysteine levels were measured using a commercially available enzyme-linked immunosorbent assay kit. DNA was extracted from peripheral blood leukocytes and real-time polymerase chain reaction was performed for genotyping of the samples. Patients were genotyped using predesigned TaqMan(®) single nucleotide polymorphism genotyping assays for two exon variations (rs1801131, rs1801133) in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene and one intron variation (rs8006686) in the methylenetetrahydrofolate dehydrogenase (MTHFD1) gene. RESULTS: Homocysteine levels were slightly higher in the patient group (POAG and PXFG) compared with controls, but the difference did not reach statistical significance. The minor alleles of the MTHFR single nucleotide polymorphisms showed a protective effect for POAG and showed an increased risk for PXFG, but none of these associations reached statistical significance (P>0.05). The minor allele of MTHFD1 rs8006686 showed a trend for increased risk of both POAG and PXFG (P>0.05). No statistically significant interaction was seen between the genetic variants and homocysteine levels (P>0.05). CONCLUSION: Our results show that neither the examined single nucleotide polymorphisms from genes involved in the pathway of homocysteine metabolism nor the measured homocysteine levels were associated with POAG or PXFG in our study cohort.

FLT1 genetic variation predisposes to neovascular AMD in ethnically diverse populations and alters systemic FLT1 expression.

PURPOSE: Current understanding of the genetic risk factors for age-related macular degeneration (AMD) is not sufficiently predictive of the clinical course. The VEGF pathway is a key therapeutic target for treatment of neovascular AMD; however, risk attributable to genetic variation within pathway genes is unclear. We sought to identify single nucleotide polymorphisms (SNPs) associated with AMD within the VEGF pathway. METHODS: Using a tagSNP, direct sequencing and meta-analysis approach within four ethnically diverse cohorts, we identified genetic risk present in FLT1, though not within other VEGF pathway genes KDR, VEGFA, or VASH1. We used ChIP and ELISA in functional analysis. RESULTS: The FLT1 SNPs rs9943922, rs9508034, rs2281827, rs7324510, and rs9513115 were significantly associated with increased risk of neovascular AMD. Each association was more significant after meta-analysis than in any one of the four cohorts. All associations were novel, within noncoding regions of FLT1 that do not tag for coding variants in linkage disequilibrium. Analysis of soluble FLT1 demonstrated higher expression in unaffected individuals homozygous for the FLT1 risk alleles rs9943922 (P = 0.0086) and rs7324510 (P = 0.0057). In silico analysis suggests that these variants change predicted splice sites and RNA secondary structure, and have been identified in other neovascular pathologies. These data were supported further by murine chromatin immunoprecipitation demonstrating that FLT1 is a target of Nr2e3, a nuclear receptor gene implicated in regulating an AMD pathway. CONCLUSIONS: Although exact variant functions are not known, these data demonstrate relevancy across ethnically diverse genetic backgrounds within our study and, therefore, hold potential for global efficacy.

Ocular symptomatology, management, and clinical outcome of a giant intracranial aneurysm.

Giant aneurysms of the anterior intracranial circulation are rare, slowly progressive vascular abnormalities, often presenting with neuro-ophthalmological symptoms before they rupture. This is a case of a 55-year-old woman with a double aneurysm of the anterior intracranial circulation, part of which was giant, diagnosed exclusively on the basis of ocular manifestations. We also describe successful management of the case throughout a long follow-up period.

Intravitreal bevacizumab for photodynamic therapy-induced massive macular detachment in acute central serous chorioretinopathy.

We present a long followed up case of acute central serous chorioretinopathy (CSC) complicated by a severe visual loss due to massive pigment epithelium detachment of the macula after a full-dose photodynamic therapy (PDT). Rapid anatomical and functional improvement was observed after a single intravitreal injection of bevacizumab. To our knowledge, we report the first case of PDT-treated CSC complicated by severe visual loss. We can only speculate that the serous detachment of the posterior pole might have been caused by PDT-induced VEGF overexpression, explaining such an impressive response to Avastin treatment.

Influence of ROBO1 and RORA on risk of age-related macular degeneration reveals genetically distinct phenotypes in disease pathophysiology.

ROBO1 is a strong candidate gene for age-related macular degeneration (AMD) based upon its location under a linkage peak on chromosome 3p12, its expression pattern, and its purported function in a pathway that includes RORA, a gene previously associated with risk for neovascular AMD. Previously, we observed that expression of ROBO1 and RORA is down-regulated among wet AMD cases, as compared to their unaffected siblings. Thus, we hypothesized that contribution of association signals in ROBO1, and interaction between these two genes may be important for both wet and dry AMD. We evaluated association of 19 single nucleotide polymorphisms (SNPs) in ROBO1 with wet and dry stages of AMD in a sibling cohort and a Greek case-control cohort containing 491 wet AMD cases, 174 dry AMD cases and 411 controls. Association signals and interaction results were replicated in an independent prospective cohort (1070 controls, 164 wet AMD cases, 293 dry AMD cases). The most significantly associated ROBO1 SNPs were rs1387665 under an additive model (meta P = 0.028) for wet AMD and rs9309833 under a recessive model (meta P = 6 × 10(-4)) for dry AMD. Further analyses revealed interaction between ROBO1 rs9309833 and RORA rs8034864 for both wet and dry AMD (interaction P<0.05). These studies were further supported by whole transcriptome expression profile studies from 66 human donor eyes and chromatin immunoprecipitation assays from mouse retinas. These findings suggest that distinct ROBO1 variants may influence the risk of wet and dry AMD, and the effects of ROBO1 on AMD risk may be modulated by RORA variants.

Vision-specific quality of life in Greek glaucoma patients.

PURPOSE: The aim of the study was to assess the vision-specific quality-of-life (VS-QoL) of Greek glaucoma patients, and the impact of potential influencing factors. METHODS: This was a 2-center, cross-sectional study. One hundred twenty-one patients were recruited from the outpatient glaucoma service and 100 successfully responded to the self-administered, Greek version of the National Eye Institute Visual Function Questionnaire 25. The results were quantified in terms of scores (0-100) and correlations with possible modifiers were investigated. The effects of sex, income, education, and comorbidities on VS-QoL scores were examined by analysis of variance. RESULTS: Our sample consisted of 49 men and 51 women with a mean age of 64.1 years, ranging from 18 to 89 years. The QoL score (mean+/-SD) was 81.7+/-14.7, the mean general health subscale score was 57.3+/-21.0 and the mean general vision subscale score was 72.7+/-16.3. Men generally presented higher VS-QoL scores (P=0.042). Age had a negative impact on the "General health" (rho=-0.325, P=0.001) and "General vision" (rho=-0.265, P=0.008) subscales. Higher educational background contributed to higher scores in General health, "General vision," and "Central vision" while urban residence correlated with "Distant activities" and "Social functioning". Cup-to-disc ratio, visual acuity and visual field indices like the Advanced Glaucoma Intervention Study, the Hodapp-Anderson-Parrish, and the Collaborative Initial Glaucoma Treatment Study scores, and pattern standard deviation and mean deviation all correlated with National Eye Institute Visual Function Questionnaire scores (r values ranging from -0.240 to 0.757). CONCLUSIONS: In this first study in a Greek native population, both the structural measure of cup-to-disc ratio and a multitude of functional scores correlated with VS-QoL scores in glaucoma patients.

Ocular disorders as the prevailing manifestations of antiphospholipid syndrome: a case series.

INTRODUCTION: Antiphospholipid syndrome is an autoimmune disorder characterized by either a history of vascular thrombosis (one or more clinical episodes of arterial, venous, or small vessel thrombosis in any tissue or organ) or pregnancy morbidity in association with the presence of antiphospholipid antibodies. The systemic features of the syndrome are characterized by large variability depending on the affected organ(s). Among them, neurological and behavioural disturbances, dermatological features as livedo reticularis and renal, ocular, liver or valvular heart manifestations have been reported in antiphospholipid syndrome patients. However, studies on the frequency and clinical presentation of the ocular manifestations as the prevailing (first) sign of antiphospholipid syndrome in patients suffering from "unexplained" ocular disease are missing. Herein, we present three cases suffering from unexplained ocular disease as first manifestation of antiphospholipid syndrome. CASE PRESENTATION: All the three patients were referred to our department because of unexplained ocular features from the anterior or posterior segment and unexplained neuro-ophthalmologic symptoms. The first patient had bilateral retinal occlusive disease, the second and the third patient had unilateral nonarteritic anterior ischemic optic neuropathy with macular oedema. Moderate to high levels of antiphospholipid antibodies were detected in all of them at baseline as well as 6 to 12 weeks after initial testing confirming the presence of antiphospholipid antibodies. Anticoagulant treatment with acenocoumarol was instituted resulting in stabilization and/or improvement of ocular signs in all of them. CONCLUSION: Due to the important diagnostic and therapeutic implications of antiphospholipid syndrome, the possibility of ocular features as the first clinical manifestation of antiphospholipid syndrome should be kept in mind of the physicians particularly in patients with no evident risk factors for ocular disease. In this case, prompt anticoagulant treatment and close follow-up seem to be essential for vision salvation and stabilization.