Schneider EW, Elner SG, van Kuijk FJ, Goldberg N, Lieberman RM, Eliott D, Johnson MW. Chronic retinal necrosis: cytomegalovirus necrotizing retinitis associated with panretinal vasculopathy in non-HIV patients. Retina 2013;33(9):1791-9.Abstract
PURPOSE: To characterize a unique cytomegalovirus (CMV)-associated retinopathy in patients with limited immune dysfunction. METHODS: Retrospective observational case series. CMV was confirmed as the pathogenic agent via polymerase chain reaction analysis of aqueous or vitreous humor samples or via immunohistochemical analysis of retinal biopsy specimens. RESULTS: Five non-HIV patients with granular necrotizing retinitis, vitritis, and severe occlusive vasculopathy were identified. Patient histories all suggested a basis for limited immune dysfunction including advanced age (n = 4), diabetes mellitus (n = 4), and noncytotoxic immunotherapy (n = 3). Diagnosis of CMV retinitis was delayed in all cases and patients received either no antiviral therapy (n = 2) or incorrect antiviral therapy (n = 3) for presumed herpes simplex/varicella zoster-related acute retinal necrosis. Retinitis subsequently regressed in all cases with introduction of systemic ganciclovir/valganciclovir (n = 5) and/or intravitreal foscarnet (n = 2). Four of five patients developed neovascularization because of extensive retinal ischemia. CONCLUSION: The clinical expression of CMV-associated retinopathy is strongly related to immune status. In patients with limited immune dysfunction, a mixed clinical picture of intraocular inflammation with panretinal occlusive vasculopathy, more characteristic of acute retinal necrosis, and peripheral slowly progressive granular retinitis, more characteristic of classic CMV retinitis, is observed. Recognition of this atypical clinical presentation, which the authors term chronic retinal necrosis, should prompt molecular testing for CMV to determine the appropriate antiviral therapy. Consideration should also be given to prophylactic panretinal photocoagulation in such eyes, given the high risk of neovascular complications.
Miller JW. Age-related macular degeneration revisited--piecing the puzzle: the LXIX Edward Jackson memorial lecture. Am J Ophthalmol 2013;155(1):1-35.e13.Abstract
PURPOSE: To present the current understanding of age-related macular degeneration (AMD) pathogenesis, based on clinical evidence, epidemiologic data, histopathologic examination, and genetic data; to provide an update on current and emerging therapies; and to propose an integrated model of the pathogenesis of AMD. DESIGN: Review of published clinical and experimental studies. METHODS: Analysis and synthesis of clinical and experimental data. RESULTS: We are closer to a complete understanding of the pathogenesis of AMD, having progressed from clinical observations to epidemiologic observations and clinical pathologic correlation. More recently, modern genetic and genomic studies have facilitated the exploration of molecular pathways. It seems that AMD is a complex disease that results from the interaction of genetic susceptibility with aging and environmental factors. Disease progression also seems to be driven by a combination of genetic and environmental factors. CONCLUSIONS: Therapies based on pathophysiologic features have changed the paradigm for treating neovascular AMD. With improved understanding of the underlying genetic susceptibility, we can identify targets to halt early disease and to prevent progression and vision loss.
Robinson CM, Zhou X, Rajaiya J, Yousuf MA, Singh G, DeSerres JJ, Walsh MP, Wong S, Seto D, Dyer DW, Chodosh J, Jones MS. Predicting the next eye pathogen: analysis of a novel adenovirus. MBio 2013;4(2):e00595-12.Abstract
UNLABELLED: For DNA viruses, genetic recombination, addition, and deletion represent important evolutionary mechanisms. Since these genetic alterations can lead to new, possibly severe pathogens, we applied a systems biology approach to study the pathogenicity of a novel human adenovirus with a naturally occurring deletion of the canonical penton base Arg-Gly-Asp (RGD) loop, thought to be critical to cellular entry by adenoviruses. Bioinformatic analysis revealed a new highly recombinant species D human adenovirus (HAdV-D60). A synthesis of in silico and laboratory approaches revealed a potential ocular tropism for the new virus. In vivo, inflammation induced by the virus was dramatically greater than that by adenovirus type 37, a major eye pathogen, possibly due to a novel alternate ligand, Tyr-Gly-Asp (YGD), on the penton base protein. The combination of bioinformatics and laboratory simulation may have important applications in the prediction of tissue tropism for newly discovered and emerging viruses. IMPORTANCE: The ongoing dance between a virus and its host distinctly shapes how the virus evolves. While human adenoviruses typically cause mild infections, recent reports have described newly characterized adenoviruses that cause severe, sometimes fatal human infections. Here, we report a systems biology approach to show how evolution has affected the disease potential of a recently identified novel human adenovirus. A comprehensive understanding of viral evolution and pathogenicity is essential to our capacity to foretell the potential impact on human disease for new and emerging viruses.
Qazi Y, Hamrah P. Corneal Allograft Rejection: Immunopathogenesis to Therapeutics. J Clin Cell Immunol 2013;2013(Suppl 9)Abstract
Corneal transplantation is among the most successful solid organ transplants. However, despite low rejection rates of grafts in the 'low-risk' setting, rejection can be as high as 70% when grafted into 'high-risk' recipient beds. Under normal homeostatic conditions, the avascular cornea provides a unique environment that facilitates immune and angiogenic privilege. An imbalance in pro-inflammatory, angiogenic and lymphangiogenic mediators leads to a breakdown in corneal immune privilege with a consequent host response against the donor graft. Recent developments in lamellar and endothelial keratoplasties have reduced the rates of graft rejection even more, while providing improved visual outcomes. The corneal layer against which an immune response is initiated, largely determines reversibility of the acute episode. While epithelial and stromal graft rejection may be treated with topical corticosteroids with higher success, acute endothelial rejection mandates a more aggressive approach to therapy due to the lack of regenerative capacity of this layer. However, current immunosuppressive regimens come with the caveat of ocular and systemic side effects, making prolonged aggressive treatment undesirable. With the advent of biologics, efficacious therapies with a superior side effect profile are on the horizon. In our review we discuss the mediators of ocular immune privilege, the roles of cellular and molecular immune players in graft rejection, with a focus on human leukocyte antigen and antigen presenting cells. Furthermore, we discuss the clinical risk factors for graft rejection and compare rates of rejection in lamellar and endothelial keratoplasties to traditional penetrating keratoplasty. Lastly, we present the current and upcoming measures of therapeutic strategies to manage and treat graft rejection, including an overview of biologics and small molecule therapy.
Patel MM, Lefebvre DR, Lee GN, Brachtel E, Rizzo J, Freitag SK. Gaze-evoked amaurosis from orbital breast carcinoma metastasis. Ophthalmic Plast Reconstr Surg 2013;29(4):e98-e101.Abstract
Gaze-evoked amaurosis (GEA) is a transient monocular vision loss provoked by eccentric gaze. Gaze-evoked amaurosis has been associated with a variety of orbital lesions, most commonly optic nerve sheath meningiomas and cavernous hemangiomas. The authors describe the first report in the literature of GEA as the presenting symptom of an orbital metastasis. The patient was a 47-year-old woman with a history of breast cancer with no known history of metastasis or active disease who presented with several weeks of vision loss in the OD upon rightward gaze. She was found to have enophthalmos and optic disc edema of the OD. Imaging revealed an intraorbital lesion, and a biopsy was consistent with a scirrhous metastasis of her breast carcinoma. This case highlights the importance of considering orbital metastases among the differential for gaze-evoked amaurosis.
Pasquale LR, Brusie S. The blue arc entoptic phenomenon in glaucoma (an American ophthalmological thesis). Trans Am Ophthalmol Soc 2013;111:46-55.Abstract
PURPOSE: To determine whether the blue arc entoptic phenomenon, a positive visual response originating from the retina with a shape that conforms to the topology of the nerve fiber layer, is depressed in glaucoma. METHODS: We recruited a cross-sectional, nonconsecutive sample of 202 patients from a single institution in a prospective manner. Subjects underwent full ophthalmic examination, including standard automated perimetry (Humphrey Visual Field 24-2) or frequency doubling technology (Screening C 20-5) perimetry. Eligible patients viewed computer-generated stimuli under conditions chosen to optimize perception of the blue arcs. Unmasked testers instructed patients to report whether they were able to perceive blue arcs but did not reveal what response was expected. We created multivariable logistic regression models to ascertain the demographic and clinical parameters associated with perceiving the blue arcs. RESULTS: In multivariable analyses, each 0.1 unit increase in cup-disc ratio was associated with 36% reduced likelihood of perceiving the blue arcs (odds ratio [OR] = 0.66 [95% confidence interval (CI): 0.53-0.83], P<.001). A smaller mean defect was associated with an increased likelihood of perceiving the blue arcs (OR=1.79 [95% CI: 1.40-2.28]); P<.001), while larger pattern standard deviation (OR=0.72 [95% CI: 0.57-0.91]; P=.005) and abnormal glaucoma hemifield test (OR=0.25 [0.10-0.65]; P=.006) were associated with a reduced likelihood of perceiving them. Older age and media opacity were also associated with an inability to perceive the blue arcs. CONCLUSION: In this study, the inability to perceive the blue arcs correlated with structural and functional features associated with glaucoma, although older age and media opacity were also predictors of this entoptic response.
Palioura S, Kim B, Dohlman CH, Chodosh J. The Boston keratoprosthesis type I in mucous membrane pemphigoid. Cornea 2013;32(7):956-61.Abstract
PURPOSE: To evaluate the use of the Boston keratoprosthesis type I implantation in patients with mucous membrane pemphigoid (MMP). METHODS: Retrospective review of 8 eyes of 8 patients with severe ocular surface disease and corneal blindness as a result of MMP who underwent Boston keratoprosthesis type I implantation at the Massachusetts Eye and Ear Infirmary from January 1, 2000, through December 31, 2009. The main outcome measures were best-corrected visual acuity, keratoprosthesis retention, and postoperative complications. RESULTS: The mean age of patients was 71.3 years (range, 55-94 years), and the mean duration of their disease preoperatively was 6.1 years (range, 1.7-11.4 years). Visual acuity after the surgery improved to 20/200 or better in 6 eyes (75%) and to 20/40 or better in 3 eyes (37.5%). Only 1 of 6 eyes (16.7%) was able to maintain visual acuity of 20/200 or better over a mean follow-up period of 3.2 years. Five of the 8 Boston keratoprosthesis type I devices (62.5%) extruded or had to be replaced during a mean follow-up time of 1.7 ± 1.7 years. Loss of vision to worse than 20/200 during the follow-up period occurred because of keratoprosthesis type I extrusion, end-stage glaucoma, and retinal or choroidal detachment. CONCLUSIONS: The clinical outcomes of Boston keratoprosthesis type I implantation in MMP are guarded and, as judged from the literature, less favorable than those with the Boston keratoprosthesis type II for the same disease.
Ojha P, Wiggs JL, Pasquale LR. The genetics of intraocular pressure. Semin Ophthalmol 2013;28(5-6):301-5.Abstract
Glaucoma is a leading cause of irreversible blindness. Intraocular pressure (IOP) is the only modifiable risk factor for glaucoma, yet there is little known about the molecular events that regulate IOP. Genetic and genomic studies have helped identify genes that influence IOP and could lead to the identification of biological pathways that serve as targets for novel pressure-modifying therapies. Genetic linkage studies resulted in the identification of several genes that cause Mendelian (autosomal dominant or autosomal recessive) forms of high-pressure glaucoma, including MYOC. PITX2, FOXC1, and CYP1B1. Classical twin studies suggest that IOP is a heritable trait. More recently, genome-wide association studies (GWAS) have shown that common genetic variants in the GAS7 and TMCO1 genomic regions are associated with elevated IOP. TMCO1 has also been associated with primary open-angle glaucoma in patients with advanced disease. A further study identifying additional genes contributing to IOP will be necessary to fully define the underlying genetic architecture of IOP.
Schrems-Hoesl LM, Schrems WA, Cruzat A, Shahatit BM, Bayhan HA, Jurkunas UV, Hamrah P. Cellular and subbasal nerve alterations in early stage Fuchs' endothelial corneal dystrophy: an in vivo confocal microscopy study. Eye (Lond) 2013;27(1):42-9.Abstract
PURPOSE: To analyze the morphology and density of corneal epithelial cells, keratocytes, and subbasal nerves, in patients with early stage Fuchs' endothelial corneal dystrophy (FECD) by in vivo confocal microscopy (IVCM). METHODS: IVCM (Confoscan 4, Nidek, Inc.) of the central cornea was performed in 30 corneas of 30 patients with early stage FECD and 13 corneas of 13 normal controls. Images were analyzed for morphology and density of the superficial and basal epithelial cells, keratocyte density, endothelial cell density (ECD), as well as subbasal corneal nerve parameters. Central corneal thickness (CCT) was measured in all patients and normals by ultrasound pachymetry. RESULTS: The ECD was significantly lower (-45.5%, P<0.001) in FECD patients as compared with controls. Total number of nerves and main nerve trunks were significantly reduced (-46.3%, P<0.001; -39.7%, P<0.001) in patients with FECD. Posterior keratocyte density was significantly higher in FECD patients (P<0.001). Significant inverse correlations were found between CCT and total number of nerves (r=-0.69, P<0.001), CCT and main nerve trunks (-0.47, P=0.016), as well as CCT and total nerve length (r=-0.62, P=0.006). Significant correlation was found between ECD and total number of nerves (r=0.44, P=0.012) as well as between ECD and main nerve trunks (r=0.65, P<0.001). CONCLUSIONS: IVCM demonstrates alterations in corneal innervation in patients with early stage FECD, suggesting a potential role of corneal nerves in the pathogenesis of FECD. Additional studies are required to investigate whether subbasal nerve alterations are caused by nonspecific corneal edema, from FECD-induced decrease in ECD, or potentially leading to loss of endothelial cells.
Mizeracka K, Trimarchi JM, Stadler MB, Cepko CL. Analysis of gene expression in wild-type and Notch1 mutant retinal cells by single cell profiling. Dev Dyn 2013;242(10):1147-59.Abstract
BACKGROUND: The vertebrate retina comprises sensory neurons, the photoreceptors, as well as many other types of neurons and one type of glial cell. These cells are generated by multipotent and restricted retinal progenitor cells (RPCs), which express Notch1. Loss of Notch1 in RPCs late during retinal development results in the overproduction of rod photoreceptors at the expense of interneurons and glia. RESULTS: To examine the molecular underpinnings of this observation, microarray analysis of single retinal cells from wild-type or Notch1 conditional knockout retinas was performed. In situ hybridization was carried out to validate some of the findings. CONCLUSIONS: The majority of Notch1-mutant cells lost expression of known Notch target genes. These cells also had low levels of RPC and cell cycle genes, and robustly up-regulated rod precursor genes. In addition, single wild-type cells, in which cell cycle marker genes were down-regulated, expressed markers of both rod photoreceptors and interneurons.
Rose AM, Shah AZ, Alfano G, Bujakowska KM, Barker AF, Robertson LJ, Rahman S, Sánchez LV, Diaz-Corrales FJ, Chakarova CF, Krishna A, Bhattacharya SS. A Study into the Evolutionary Divergence of the Core Promoter Elements of PRPF31 and TFPT. J Mol Genet Med 2013;7(2)Abstract
Mutations in have been implicated in retinitis pigmentosa, a blinding disease caused by degeneration of rod photoreceptors. The disease mechanism in the majority of cases is haploinsufficiency. Crucially, attempts at generation of animal models of disease have proved unsuccessful, yielding animals with a visual phenotype that does not mirror human disease. This suggests that, in these animals, the transcriptional regulation of is different to humans and compared to other species. Study of the evolution of the core promoter has important implications for our understanding of human disease, as disease phenotype is modified by differentially expressed alleles in the population. lies in a head-to-head arrangement with , a gene involved in cellular apoptosis. The two genes were shown to share common regulatory elements in the human genome. In this study, the core promoters of and were characterised by dual-luciferase reporter assay using genomic DNA from the green monkey, domestic dog and house mouse. It was found that the core promoters were conserved between human and monkey. In dog, the core promoter was conserved, but different gene architecture meant the gene was controlled by a long-range promoter lying some 2000bp from the transcription start site. There was very low level of conservation (<20%) of the 5' region between mouse and human. It was shown that mouse populations did not show variable expression levels, revealing a potential explanation for the lack of phenotype observed in the knock-out mouse model.
Mendoza PR, Jakobiec FA, Townsend DJ. Bilateral nevus comedonicus of the eyelids. Ophthalmic Plast Reconstr Surg 2013;29(4):e95-8.Abstract
Nevus comedonicus is a rare developmental abnormality of the infundibulum of the hair follicle. It is usually unilateral and commonly presents at birth or during childhood. A rare case of late-onset, bilateral nevus comedonicus of the eyelids is reported. A 79-year-old man presented with asymptomatic but disfiguring eyelid lesions noted several months earlier. On physical examination, multiple papules resembling comedones were present bilaterally in the eyelids, canthi, temple regions, and bridge of the nose. Microscopically, there were deep invaginations of the follicular canals forming focal tunnels or pseudosinus tracts with poral openings to the surface. These variably cystic structures were lined by keratinizing and nonkeratinizing squamous epithelium, contained concentric lamellae of keratin in their lumens, and some were acutely or chronically inflamed. The diagnosis of a nevus comedonicus was made. The clinical and histopathologic characteristics, pathogenesis, differential diagnosis, and management of nevus comedonicus are briefly discussed.
Pennock S, Kim D, Mukai S, Kuhnle M, Chun DW, Matsubara J, Cui J, Ma P, Maberley D, Samad A, Van Geest RJ, Oberstein SL, Schlingemann RO, Kazlauskas A. Ranibizumab is a potential prophylaxis for proliferative vitreoretinopathy, a nonangiogenic blinding disease. Am J Pathol 2013;182(5):1659-70.Abstract
Proliferative vitreoretinopathy (PVR) exemplifies a disease that is difficult to predict, lacks effective treatment options, and substantially reduces the quality of life of an individual. Surgery to correct a rhegmatogenous retinal detachment fails primarily because of PVR. Likely mediators of PVR are growth factors in vitreous, which stimulate cells within and behind the retina as an inevitable consequence of a breached retina. Three classes of growth factors [vascular endothelial growth factor A (VEGF-A), platelet-derived growth factors (PDGFs), and non-PDGFs (growth factors outside of the PDGF family)] are relevant to PVR pathogenesis because they act on PDGF receptor α, which is required for experimental PVR and is associated with this disease in humans. We discovered that ranibizumab (a clinically approved agent that neutralizes VEGF-A) reduced the bioactivity of vitreous from patients and experimental animals with PVR, and protected rabbits from developing disease. The apparent mechanism of ranibizumab action involved derepressing PDGFs, which, at the concentrations present in PVR vitreous, inhibited non-PDGF-mediated activation of PDGF receptor α. These preclinical findings suggest that available approaches to neutralize VEGF-A are prophylactic for PVR, and that anti-VEGF-based therapies may be effective for managing more than angiogenesis- and edema-driven pathological conditions.
Pasquale LR, Loomis SJ, Weinreb RN, Kang JH, Yaspan BL, Bailey JC, Gaasterland D, Gaasterland T, Lee RK, Scott WK, Lichter PR, Budenz DL, Liu Y, Realini T, Friedman DS, McCarty CA, Moroi SE, Olson L, Schuman JS, Singh K, Vollrath D, Wollstein G, Zack DJ, Brilliant M, Sit AJ, Christen WG, Fingert J, Kraft P, Zhang K, Allingham RR, Pericak-Vance MA, Richards JE, Hauser MA, Haines JL, Wiggs JL. Estrogen pathway polymorphisms in relation to primary open angle glaucoma: an analysis accounting for gender from the United States. Mol Vis 2013;19:1471-81.Abstract
PURPOSE: Circulating estrogen levels are relevant in glaucoma phenotypic traits. We assessed the association between an estrogen metabolism single nucleotide polymorphism (SNP) panel in relation to primary open angle glaucoma (POAG), accounting for gender. METHODS: We included 3,108 POAG cases and 3,430 controls of both genders from the Glaucoma Genes and Environment (GLAUGEN) study and the National Eye Institute Glaucoma Human Genetics Collaboration (NEIGHBOR) consortium genotyped on the Illumina 660W-Quad platform. We assessed the relation between the SNP panels representative of estrogen metabolism and POAG using pathway- and gene-based approaches with the Pathway Analysis by Randomization Incorporating Structure (PARIS) software. PARIS executes a permutation algorithm to assess statistical significance relative to the pathways and genes of comparable genetic architecture. These analyses were performed using the meta-analyzed results from the GLAUGEN and NEIGHBOR data sets. We evaluated POAG overall as well as two subtypes of POAG defined as intraocular pressure (IOP) ≥22 mmHg (high-pressure glaucoma [HPG]) or IOP <22 mmHg (normal pressure glaucoma [NPG]) at diagnosis. We conducted these analyses for each gender separately and then jointly in men and women. RESULTS: Among women, the estrogen SNP pathway was associated with POAG overall (permuted p=0.006) and HPG (permuted p<0.001) but not NPG (permuted p=0.09). Interestingly, there was no relation between the estrogen SNP pathway and POAG when men were considered alone (permuted p>0.99). Among women, gene-based analyses revealed that the catechol-O-methyltransferase gene showed strong associations with HTG (permuted gene p≤0.001) and NPG (permuted gene p=0.01). CONCLUSIONS: The estrogen SNP pathway was associated with POAG among women.