September 2016

PURPOSE: Accumulation of oxidized phospholipids/lipoproteins with age is suggested to contribute to the pathogenesis of AMD. We investigated the effect of oxidized LDL (ox-LDL) on human RPE cells. METHODS: Primary human fetal RPE (hf-RPE) and ARPE-19 cells were treated with different doses of LDL or ox-LDL. Assessment of cell death was measured by lactate dehydrogenase release into the conditioned media. Barrier function of RPE was assayed by measuring transepithelial resistance. Lysosomal accumulation of ox-LDL was determined by immunostaining. Expression of CD36 was determined by RT-PCR; protein blot and function was examined by receptor blocking. NLRP3 inflammasome activation was assessed by RT-PCR, protein blot, caspase-1 fluorescent probe assay, and inhibitor assays. RESULTS: Treatment with ox-LDL, but not LDL, for 48 hours caused significant increase in hf-RPE and ARPE-19 (P < 0.001) cell death. Oxidized LDL treatment of hf-RPE cells resulted in a significant decrease in transepithelial resistance (P < 0.001 at 24 hours and P < 0.01 at 48 hours) relative to LDL-treated and control cells. Internalized ox-LDL was targeted to RPE lysosomes. Uptake of ox-LDL but not LDL significantly increased CD36 protein and mRNA levels by more than 2-fold. Reverse transcription PCR, protein blot, and caspase-1 fluorescent probe assay revealed that ox-LDL treatment induced NLRP3 inflammasome when compared with LDL treatment and control. Inhibition of NLRP3 activation using 10 μM isoliquiritigenin significantly (P < 0.001) inhibited ox-LDL induced cytotoxicity. CONCLUSIONS: These data are consistent with the concept that ox-LDL play a role in the pathogenesis of AMD by NLRP3 inflammasome activation. Suppression of NLRP3 inflammasome activation could attenuate RPE degeneration and AMD progression.

PURPOSE: To determine whether hyperreflective foci (HF) and macular thickness on spectral domain ocular coherence tomography are associated with lipid levels in patients with Type 2 diabetes. METHODS: Two hundred and thirty-eight participants from four sites had fundus photographs and spectral domain ocular coherence tomography images graded for hard exudates and HF, respectively. Regression models were used to determine the association between serum lipid levels and 1) presence of HF and hard exudates and 2) central subfield macular thickness, central subfield macular volume, and total macular volume. RESULTS: All patients with hard exudates on fundus photographs had corresponding HF on spectral domain ocular coherence tomography, but 57% of patients with HF on optical coherence tomography did not have hard exudates detected in their fundus photographs. Presence of HF was associated with higher total cholesterol (odds ratio = 1.13, 95% confidence interval = 1.01-1.27, P = 0.03) and higher low-density lipoprotein levels (odds ratio = 1.17, 95% confidence interval = 1.02-1.35, P = 0.02) in models adjusting for other risk factors. The total macular volume was also associated with higher total cholesterol (P = 0.009) and triglyceride (P = 0.02) levels after adjusting for other risk factors. CONCLUSION: Higher total and low-density lipoprotein cholesterol were associated with presence of HF on spectral domain ocular coherence tomography. Total macular volume was associated with higher total cholesterol and triglyceride levels.

Primary open angle glaucoma (POAG) is a complex disease and is one of the major leading causes of blindness worldwide. Genome-wide association studies have successfully identified several common variants associated with glaucoma; however, most of these variants only explain a small proportion of the genetic risk. Apart from the standard approach to identify main effects of variants across the genome, it is believed that gene-gene interactions can help elucidate part of the missing heritability by allowing for the test of interactions between genetic variants to mimic the complex nature of biology. To explain the etiology of glaucoma, we first performed a genome-wide association study (GWAS) on glaucoma case-control samples obtained from electronic medical records (EMR) to establish the utility of EMR data in detecting non-spurious and relevant associations; this analysis was aimed at confirming already known associations with glaucoma and validating the EMR derived glaucoma phenotype. Our findings from GWAS suggest consistent evidence of several known associations in POAG. We then performed an interaction analysis for variants found to be marginally associated with glaucoma (SNPs with main effect p-value <0.01) and observed interesting findings in the electronic MEdical Records and GEnomics Network (eMERGE) network dataset. Genes from the top epistatic interactions from eMERGE data (Likelihood Ratio Test i.e. LRT p-value <1e-05) were then tested for replication in the NEIGHBOR consortium dataset. To replicate our findings, we performed a gene-based SNP-SNP interaction analysis in NEIGHBOR and observed significant gene-gene interactions (p-value <0.001) among the top 17 gene-gene models identified in the discovery phase. Variants from gene-gene interaction analysis that we found to be associated with POAG explain 3.5% of additional genetic variance in eMERGE dataset above what is explained by the SNPs in genes that are replicated from previous GWAS studies (which was only 2.1% variance explained in eMERGE dataset); in the NEIGHBOR dataset, adding replicated SNPs from gene-gene interaction analysis explain 3.4% of total variance whereas GWAS SNPs alone explain only 2.8% of variance. Exploring gene-gene interactions may provide additional insights into many complex traits when explored in properly designed and powered association studies.

Purpose: Recent studies indicate that mitochondrial proteins may contribute to the pathogenesis of primary open-angle glaucoma (POAG). In this study, we examined the association between POAG and common variations in gene-encoding mitochondrial proteins. Methods: We examined genetic data from 3430 POAG cases and 3108 controls derived from the combination of the GLAUGEN and NEIGHBOR studies. We constructed biological-system coherent mitochondrial nuclear-encoded protein gene-sets by intersecting the MitoCarta database with the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. We examined the mitochondrial gene-sets for association with POAG and with normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) subsets using Pathway Analysis by Randomization Incorporating Structure. Results: We identified 22 KEGG pathways with significant mitochondrial protein-encoding gene enrichment, belonging to six general biological classes. Among the pathway classes, mitochondrial lipid metabolism was associated with POAG overall (P = 0.013) and with NTG (P = 0.0006), and mitochondrial carbohydrate metabolism was associated with NTG (P = 0.030). Examining the individual KEGG pathway mitochondrial gene-sets, fatty acid elongation and synthesis and degradation of ketone bodies, both lipid metabolism pathways, were significantly associated with POAG (P = 0.005 and P = 0.002, respectively) and NTG (P = 0.0004 and P < 0.0001, respectively). Butanoate metabolism, a carbohydrate metabolism pathway, was significantly associated with POAG (P = 0.004), NTG (P = 0.001), and HTG (P = 0.010). Conclusions: We present an effective approach for assessing the contributions of mitochondrial genetic variation to open-angle glaucoma. Our findings support a role for mitochondria in POAG pathogenesis and specifically point to lipid and carbohydrate metabolism pathways as being important.

OBJECTIVES: To assess resident cataract surgery outcomes at an academic teaching institution using 2 Physician Quality Reporting System (PQRS) cataract measures, which are intended to serve as a proxy for quality of surgical care. DESIGN: A retrospective review comparing cataract surgery outcomes of resident and attending surgeries using 2 PQRS measures: (1) 20/40 or better best-corrected visual acuity following cataract surgery and (2) complications within 30 days following cataract surgery requiring additional surgical procedures. SETTING: An academic ophthalmology center. PARTICIPANTS: A total of 2487 surgeries performed at the Massachusetts Eye and Ear Infirmary from January 1, 2011 to December 31, 2012 were included in this study. RESULTS: Of all 2487 cataract surgeries, 98.95% achieved a vision of at least 20/40 at or before 90 days, and only 0.64% required a return to the operating room for postoperative complications. Of resident surgeries, 98.9% (1370 of 1385) achieved 20/40 vision at or before 90 days follow-up. Of attending surgeries, 99.0% (1091 of 1102) achieved 20/40 vision at or before 90 days (p = 1.00). There were no statistically significant differences between resident and attending cases regarding postoperative complications needing a return to the operating room (i.e., 0.65%, or 9 of 1385 resident cases vs 0.64%, or 7 of 1102 attending cases; p = 1.00). CONCLUSIONS: Using PQRS Medicare cataract surgery criteria, this study establishes new benchmarks for cataract surgery outcomes at a teaching institution and supplemental measure for assessing resident surgical performance. Excellent cataract outcomes were achieved at an academic teaching institution, with results exceeding Medicare thresholds of 50%. There appears to be no significant difference in supervised trainee and attending cataract surgeon outcomes using 2 PQRS measures currently used by Medicare to determine physician reimbursement and quality of care.

PURPOSE: To investigate the telescope use and driving patterns of bioptic drivers with age-related macular degeneration (AMD). METHODS: A questionnaire addressing telescope use and driving patterns was administered by telephone interview to three groups of bioptic drivers: AMD (n = 31; median 76 years); non-AMD first licensed with a bioptic (n = 38; 53 years); and non-AMD first licensed without a bioptic (n = 47; 37 years). Driving patterns of bioptic AMD drivers were also compared with those of normal vision (NV) drivers (n = 36; 74 years) and nonbioptic AMD drivers (n = 34; 79 years). RESULTS: Bioptic usage patterns of AMD drivers did not differ from those of the younger bioptic drivers and greater visual difficulty without the bioptic was strongly correlated with greater bioptic helpfulness. Bioptic AMD drivers were more likely to report avoidance of night driving than the age-similar NV drivers (P = 0.06). However, they reported less difficulty than the nonbioptic AMD drivers in all driving situations (P ≤ 0.02). Weekly mileages of bioptic AMD drivers were lower than those of the younger bioptic drivers (P < 0.001), but not the NV group (P = 0.54), and were higher than those of the nonbioptic AMD group (P < 0.001). CONCLUSIONS: Our results suggest that bioptic telescopes met the visual demands of drivers with AMD and that those drivers had relatively unrestricted driving habits. TRANSLATIONAL RELEVANCE: Licensure with a bioptic telescope may prolong driving of older adults with AMD; however, objective measures of bioptic use, driving performance, and safety are needed.

Histological studies from autopsy specimens have characterized hard exudates as a composition of lipid-laden macrophages or noncellular materials including lipid and proteinaceous substances (hyaline substances). However, the characteristics of hard exudates in living patients have not been examined due to insufficient resolution of existing equipment. In this study, we used adaptive optics scanning laser ophthalmoscopy (AO-SLO) to examine the characteristics of hard exudates in patients with retinal vascular diseases. High resolution imaging using AO-SLO enables morphological classification of retinal hard exudates into two types, which could not be distinguished either on fundus examination or by spectral domain optical coherence tomography (SD-OCT). One, termed a round type, consisted of an accumulation of spherical particles (average diameter of particles: 26.9 ± 4.4 μm). The other, termed an irregular type, comprised an irregularly shaped hyper-reflective deposition. The retinal thickness in regions with round hard exudates was significantly greater than the thickness in regions with irregular hard exudates (P = 0.01 →0.02). This differentiation of retinal hard exudates in patients by AO-SLO may help in understanding the pathogenesis and clinical prognosis of retinal vascular diseases.

Diabetic retinopathy (DR) is the leading cause of blindness in the working-age population in developed countries, and its prevalence will increase as the global incidence of diabetes grows exponentially. DR begins with an early nonproliferative stage in which retinal blood vessels and neurons degenerate as a consequence of chronic hyperglycemia, resulting in vasoregression and persistent retinal ischemia, metabolic disequilibrium, and inflammation. This is conducive to overcompensatory pathological neovascularization associated with advanced proliferative DR. Although DR is considered a microvascular complication, the retinal microvasculature is intimately associated with and governed by neurons and glia; neurodegeneration, neuroinflammation, and dysregulation of neurovascular cross talk are responsible in part for vascular abnormalities in both early nonproliferative DR and advanced proliferative DR. Neuronal activity directly regulates microvascular dilation and blood flow in the process of neurovascular coupling. Retinal neurons also secrete guidance cues in response to injury, ischemia, or metabolic stress that may either promote or suppress vascular outgrowth, either alleviating or exacerbating DR, contingent on the stage of disease and retinal microenvironment. Neurodegeneration, impaired neurovascular coupling, and dysregulation of neuronal guidance cues are key events in the pathogenesis of DR, and correcting these events may prevent or delay development of advanced DR. The review discusses the mechanisms of neurovascular cross talk and its dysregulation in DR, and their potential therapeutic implications.

Goblet cells within the conjunctival epithelium are specialized cells that secrete mucins onto the surface of the eye. Recent research has demonstrated new characteristics of the cells, including factors influencing their differentiation, their gene products and their functions at the ocular surface. The following review summarizes the newly discovered aspects of the role of Spdef, a member of the Ets transcription factor family in conjunctival goblet cell differentiation, the newly discovered goblet cell products including claudin2, the Wnt inhibitor Frzb, and the transmembrane mucin Muc16. The current concepts of conjunctival goblet cell function, including debris removal and immune surveillance are reviewed, as are changes in the goblet cell population in ocular surface diseases. Major remaining questions regarding conjunctival cell biology are discussed.

Current techniques for repairing large eyelid colobomas require preparation of other tissue sites and occasionally more than one procedure. We present a technique that requires only one procedure and is limited to the colobomatous eyelid; in addition, it is specifically designed to help avoid postoperative astigmatic and obstructive amblyopia. Outcomes are demonstrated in 3 cases of hemifacial microsomia. Large colobomas on the upper eyelid can be successfully and aesthetically repaired with only one procedure, incising only the congenitally abnormal eyelid.

PURPOSE: To compare microcatheter-assisted trabeculotomy with standard rigid probe trabeculotomy for the treatment of childhood glaucoma. METHODS: The early postoperative (12 months) results of microcatheter-assisted trabeculotomy (group 1) performed by single surgeon were retrospectively compared with those of rigid probe trabeculotomy (group 2) performed by the same surgeon in patients treated for childhood glaucoma. Success was defined as an intraocular pressure (IOP) <21 mm Hg with at least a 30% reduction from preoperative IOP with (qualified success) or without (complete success) the use of anti-glaucoma medication. RESULTS: A total of 43 eyes of 36 patients were included. Mean IOP in group 1 was significantly lower than that in group 2 at 6 months (17.0±5.1 vs 22.5±9.8; p=0.042), 9 months (16.3±5.0 vs 21.6±9.6; p=0.009) and 12 months (14.8±2.5 vs 19.0±7.1; p=0.049) postoperatively. The mean percentage reduction in IOP from preoperative to the last postoperative follow-up was greater in group 1 (47.3±17.7%) than in group 2 (34.2±21.9%) (p=0.036). group 1 demonstrated an 81.0% complete and 86.4% qualified success rate, exceeding the 51.6% complete (p=0.060) and 61.9% qualified (p=0.037) success rate of group 2. There were no long-term complications in either group, but choroidal detachment occurred in one eye in group 2. CONCLUSION: Microcatheter-assisted circumferential trabeculotomy is a more effective treatment and is as safe as traditional trabeculotomy with a rigid probe for primary congenital glaucoma in the early postoperative course. TRIAL REGISTRATION NUMBER: ChiCTR-OCC-15005789, Results.

The neonatal period of very preterm infants is often characterized by a difficult adjustment to extrauterine life, with an inadequate nutrient supply and insufficient levels of growth factors, resulting in poor growth and a high morbidity rate. Long-term multisystem complications include cognitive, behavioral, and motor dysfunction as a result of brain damage as well as visual and hearing deficits and metabolic disorders that persist into adulthood. Insulinlike growth factor 1 (IGF-1) is a major regulator of fetal growth and development of most organs especially the central nervous system including the retina. Glucose metabolism in the developing brain is controlled by IGF-1 which also stimulates differentiation and prevents apoptosis. Serum concentrations of IGF-1 decrease to very low levels after very preterm birth and remain low for most of the perinatal development. Strong correlations have been found between low neonatal serum concentrations of IGF-1 and poor brain and retinal growth as well as poor general growth with multiorgan morbidities, such as intraventricular hemorrhage, retinopathy of prematurity, bronchopulmonary dysplasia, and necrotizing enterocolitis. Experimental and clinical studies indicate that early supplementation with IGF-1 can improve growth in catabolic states and reduce brain injury after hypoxic/ischemic events. A multicenter phase II study is currently underway to determine whether intravenous replacement of human recombinant IGF-1 up to normal intrauterine serum concentrations can improve growth and development and reduce prematurity-associated morbidities.

Specific lineages of the commensal bacterium Enterococcus faecium belonging to CC17, especially ST412, have been isolated from patients in several hospitals worldwide and harbor antibiotic resistance genes and virulence factors. Here, we report a high-quality draft genome sequence and highlight features of E. faecium VRE16, a representative of this ST.

PURPOSE: Mutation of RGR, encoding retinal G-protein coupled receptor was originally reported in association with retinal dystrophy in 1999. A single convincing recessive variant segregated perfectly in one family of five affected and two unaffected siblings. At least one further individual, homozygous for the same variant has since been reported. The aim of this report was to reevaluate the findings in consideration of data from a whole genome sequencing (WGS) study of a large cohort of retinal dystrophy families. METHODS: Whole genome sequencing was performed on 599 unrelated probands with inherited retinal disease. Detailed phenotyping was performed, including clinical evaluation, electroretinography, fundus photography, fundus autofluorescence imaging (FAF) and spectral-domain optical coherence tomography (OCT). RESULTS: Overall we confirmed that affected individuals from six unrelated families were homozygous for both the reported RGR p.Ser66Arg variant and a nearby frameshifting deletion in CDHR1 (p.Ile841Serfs119*). All had generalized rod and cone dysfunction with severe macular involvement. An additional proband was heterozygous for the same CDHR1/RGR haplotype but also carried a second null CDHR1 mutation on a different haplotype. A comparison of the clinical presentation of the probands reported here with other CDHR1-related retinopathy patients shows the phenotypes to be similar in presentation, severity, and rod/cone involvement. CONCLUSIONS: These data suggest that the recessive retinal disorder previously reported to be due to homozygous mutation in RGR is, at least in part, due to variants in CDHR1 and that the true consequences of RGR knock-out on human retinal structure and function are yet to be determined.