Expression QTL analysis of glaucoma endophenotypes in the Norfolk Island isolate provides evidence that immune-related genes are associated with optic disc size.

Primary open-angle glaucoma (POAG) is influenced by both genetic and environmental factors. Despite significant progress in identifying genetic variants associated with POAG, there remains a substantial amount of unexplained heritability. Study design features that may enhance knowledge of the genetic architecture include focusing on multiple quantitative traits related to ocular disorders (i.e. endophenotypes), targeting genetic variants that directly influence gene expression (i.e. cis-eQTLs) and utilising genetically isolated populations to reduce genetic and environmental noise and thus enhance association signals. In this study we performed heritability and blood-based eQTL association analysis of five key POAG endophenotypes in 330 individuals from the Norfolk Island (NI) isolate. Results showed evidence of heritability for all five traits, with H2 estimates ranging from 0.35 for intraocular pressure (IOP) to 0.82 for central corneal thickness (CCT) (P < 0.05). The primary finding was for BTN3A2, whereby both cis-SNP and transcript were significantly associated with disc size within a conditional regression model. Specifically, this model included rs853676 (ß = 0.23,P = 0.008) and transcript (ß = 0.23, P = 0.03). We also observed a cis-SNP association between optic disc size and LPCAT2 independent of transcript (P = 0.0004). These genes have specific functions in immune system pathways and suggest a role for an inherited immune component of POAG risk. This study also demonstrates an alternate approach to understanding the functional genetic basis of POAG and ocular health more generally.

Fifty years later: the disk goes to the prom.

Although age-related macular degeneration is the most prevalent macular disease in the world, numerous discoveries regarding the molecular bases of vision have been made through genetic association studies of rare inherited maculopathies. In this issue of the JCI, Yang et al. present a functional genetics study that identifies a role for prominin 1 (PROM1), best known as a stem cell and/or progenitor cell marker, in the biogenesis of retinal photoreceptor disk arrays (see the related article beginning on page 2908). This study supports an established model in which disk morphogenesis occurs through membrane evagination and extends other recent studies assigning PROM1 important functions outside of the stem cell niche.

Sorafenib protects human optic nerve head astrocytes from light-induced overexpression of vascular endothelial growth factor, platelet-derived growth factor, and placenta growth factor.

OBJECTIVES: Growth factors, such as vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and placenta growth factor (PlGF) are key players in the development of diabetic retinopathy, age-related macular degeneration, and other retinal neovascular diseases. Glial cells provide a significant source of retinal growth factor production under physiologic and pathologic conditions. Cumulative light exposure has been linked to increased retinal growth factor expression. Previous reports indicate that sorafenib, an oral multikinase inhibitor, might have a beneficial effect on retinal neovascularization. This study was designed to investigate the effects of sorafenib on light-induced overexpression of growth factors in human retinal glial cells. METHODS: Primary human optic nerve head astrocytes (ONHAs) were exposed to white light and incubated with sorafenib. Viability, expression, and secretion of VEGF-A, PDGF-BB, and PlGF and their mRNA were determined by reverse transcription-polymerase chain reaction, immunohistochemistry, and enzyme-linked immunosorbent assay. RESULTS: Light exposure decreased cell viability and increased VEGF-A, PDGF-BB, and PlGF expression and secretion. These light-induced effects were significantly reduced when cells were treated with sorafenib at a concentration of 1 microg/ml. CONCLUSION: Sorafenib significantly reduced light-induced overexpression of VEGF-A, PDGF-BB, and PlGF in primary human ONHAs. Sorafenib has promising properties as a potential supportive treatment for retinal neovascularization.

High-titer collapsin response-mediating protein-associated (CRMP-5) paraneoplastic optic neuropathy and Vitritis as the only clinical manifestations in a patient with small cell lung carcinoma.

Paraneoplastic optic neuropathy (PON) is a rare syndrome usually associated with small cell lung carcinoma. In the 27 rigorously reported cases, neurologic manifestations other than visual loss have been present in all but 2. In the single case in which vision improved in response to treatment of the cancer, the collapsin response-mediating protein (CRMP)-5 titer did not change, and the ophthalmic examination was not detailed. We describe a patient with optic neuropathy and vitritis as the only clinical manifestations of PON marked by an extremely high titer of CRMP-5 antibody. Treatment of the underlying small cell lung cancer coincided with resolution of the visual abnormalities and a dramatic decrease in the CRMP-5 titer.

Serum autoantibodies to optic nerve head glycosaminoglycans in patients with glaucoma.

BACKGROUND: Serum autoantibodies that cross-react with glycosaminoglycans have been proposed to play a significant role in specific tissue injury in patients with systemic autoimmune diseases. OBJECTIVE: To investigate whether serum immunoreactivity to glycosaminoglycans is present in patients with glaucoma who have aberrant serum autoantibodies to DNA, RNA, nuclear proteins, or retinal proteins, as proteoglycans and their glycosaminoglycan side chains are important components of the optic nerve head and its vasculature. METHODS: We performed Western blotting using patient serum samples and human optic nerve head homogenates that were treated with or without specific glycosaminoglycan degrading enzymes. Monoclonal antibodies that recognize different determinants of glycosaminoglycans were used to identify specific substrate antigenicity. We compared the serum immunoreactivity to glycosaminoglycans in 60 age-matched patients with normal-pressure glaucoma, 36 patients with primary open-angle glaucoma, and 20 control subjects by enzyme-linked immunosorbent assay. In addition, immunohistochemistry was performed to compare the distribution patterns of glycosaminoglycans in the optic nerve head of postmortem eyes of age-matched patients with normal-pressure glaucoma, primary open-angle glaucoma, and control subjects. RESULTS: Western blotting demonstrated that serum samples from patients with glaucoma who have circulating autoantibodies can recognize optic nerve head proteoglycans, including chondroitin sulfate and heparan sulfate. The level of serum autoantibodies binding purified chondroitin sulfate and heparan sulfate glycosaminoglycans in an enzyme-linked immunosorbent assay was approximately 100% higher in patients with normal-pressure glaucoma than that in control subjects and approximately 50% higher than that in patients with primary open-angle glaucoma. We also observed increased immunostaining of glycosaminoglycans in the optic nerve head of eyes with glaucoma, particularly those with normal intraocular pressure, compared with control eyes. CONCLUSION: There are increased levels of autoantibodies recognizing glycosaminoglycans of the optic nerve head in the serum samples of some patients with glaucoma. CLINICAL RELEVANCE: These autoantibodies may increase the susceptibility of the optic nerve head to damage in these patients by changing the functional properties of the lamina cribrosa, its vasculature, or both.

Localization of S-antigen by enzyme-labelled antibody method and electron microscopy.

Localization of S-antigen was studied by a direct enzyme-labeled immunohistochemical method with light and electron microscopes. IgG was prepared from rabbits which were sensitized by swine retinal S-antigen and the IgG was conjugated with horseradish peroxidase (HRP). This HRP-labeled IgG was directly applied to normal rabbit retina and the retina was processed to make slides for light and electron microscopic examinations. In light microscopic findings, a clear-cut positive response was noted in the outer segment of photoreceptor cells which was similar to that of Wacker's observation, and a weak response was observed in the inner segment of the photoreceptor cells and the outer nuclear layer. In electron microscopic findings, immunoprecipitates, which were represented by electron-dense particles, were observed on both sides of the disk membrane of the outer segment with evenly distributed particles on both outer and inner surfaces, showing a pattern symmetric to that of the membrane. These immunoprecipitates were also noted in the plasma membrane of the outer segment but there they did not show a pattern similar to that of the disk membrane. A small amount of pinpoint-shaped immunoprecipitates were also noted in the cytoplasm of the inner segment and the connecting cilia. The immunoprecipitates were observed to gradually decrease in number with the phagocytosis of the outer segment by the retinal pigment epithelium, and they finally disappeared as fragments which were completely phagocytized. These findings may suggest a renewal process of S-antigen and a rationalization of this theory was discussed.

[Blind spot enlargement syndrome in acute zonal occult outer retinopathy with detection of autoantibodies against the retinal antigens CRALBP and S-Ag]. / Syndrom der Vergrößerung des blinden Flecks in akuter zonaler okkulter äußerer Retinopathie mit Nachweis von Autoantikörpern gegen die retinalen Antigene CRALBP und S-Ag.

Acute zonal occult outer retinopathy (AZOOR) is a rare disease and is part of the white dot syndrome occurring bilaterally and often asymmetrically in young healthy myopic women. Characteristic findings are distinct focal lesions of the outer segments (OS) of the photoreceptor (PR) layer and abnormalities in fundus autofluorescence (FAF) within the lesions. Currently there is a lack of defined disease criteria, such as specific laboratory findings. Also no effective therapy is known which makes it difficult to diagnose, differentiate and treat AZOOR. Supplementation of antioxidants may become part of therapeutic options in AZOOR. A 19-year-old myopic woman presented with unilaterally reduced visual acuity. Due to the clinical features and with the help of FAF, spectral domain optical coherence tomography (SD-OCT) and perimetry the diagnosis of blind spot enlargement syndrome in AZOOR was made. Identification of autoantibodies specific for two retinal antigens (CRALBP and S-Ag) supports the concept of an autoimmunological origin of the disease. Systemic steroids were given but stopped almost 6 weeks later as no improvement was seen. In follow-up controls over 12 months the clinical picture remained unchanged without any further therapy.

Bilateral autoimmune optic neuritis and vitreitis related to CRMP-5-IgG: intravitreal triamcinolone acetonide therapy of four eyes.

PURPOSE: To report the vision outcome following intravitreal triamcinolone acetonide (IVTA) as adjunctive therapy in four eyes of two patients with paraneoplastic autoimmune optic neuritis and vitreitis related to CRMP (Collapsin-Response-Mediator Protein)-5-IgG. DESIGN: Retrospective case series.MethodsChart review of four eyes. RESULTS: Preoperative visions were: patient 1, 20/50 OD, 20/25 OS; patient 2, counting fingers (CF) at two feet OD, and CF at three feet OS. At last follow-up, the postoperative visions were 20/40, 20/50 and 20/200, 20/60, respectively. All signs of optic disc swelling and vitreitis had abated. CONCLUSIONS: Use of IVTAin paraneoplastic autoimmune optic neuritis and vitreitis related to CRMP-5-IgG was followed by a marked decrease in inflammation and stabilization or improvement of vision. These observations support this form of adjunctive therapy in patients whose intraocular pathology is attributed to paraneoplastic autoimmunity.

Hypoxia/reoxygenation and TGF-beta increase alphaB-crystallin expression in human optic nerve head astrocytes.

Reactive astrocytes in glaucomatous optic nerve changes are characterized by an increased expression of alphaB-crystallin and transforming growth factor-beta (TGF-beta). In the pathogenesis of glaucomatous optic nerve damage, ischemia/reperfusion injury may play an important role. The goal of the present study was to determine the influence of hypoxia/reoxygenation and TGF-beta on the expression of alphaB-crystallin in cultured human astrocytes of the optic nerve head (ONH). Cultured human astrocytes were incubated under hypoxic conditions (1% O2 for 4-12 h) with subsequent reoxygenation (12-24 h). Additionally, cells were treated with 1.0 ng/ml TGF-beta1 and TGF-beta2 for 12-48 h. Expression of alphaB-crystallin was examined by Northern- and Western-blotting. Levels of TGF-beta1 and TGF-beta2 were analyzed by RT-PCR analysis and ELISA. The effect of TGF-beta blocking on the hypoxia/reoxygenation modulated expression of alphaB-crystallin was investigated by simultaneous incubation with neutralizing antibodies against TGF-beta during the reoxygenation phase. Hypoxia/reoxygenation increased the expression of alphaB-crystallin at the mRNA (2.8- to 3.1-fold) and protein level (1.8- to 2.1-fold). Treatment with 1.0 ng/ml TGF-beta1 and TGF-beta2 for 12-48 h markedly enhanced alphaB-crystallin mRNA expression approximately three- to fourfold. Using Western blot analysis, this increase ranged from 2 to 3 times. Both cytokines showed a twofold increase after 12 and 24 h of reoxygenation at the mRNA and a two- to threefold increase at the protein level. Simultaneous treatment with neutralizing antibodies against both TGF-beta isoforms prevented the hypoxia/reoxygenation-mediated elevation of alphaB-crystallin. The process of hypoxia/reoxygenation is capable of inducing the expression of alphaB-crystallin and TGF-ss in cultured ONH astrocytes. Therefore, optimization of conditions leading to hypoxia/reoxygenation in the ONH of glaucomatous patients may help to lower the incidence of characteristic changes in the optic nerve.

Autoantibodies in patients with glaucoma: a comparison of IgG serum antibodies against retinal, optic nerve, and optic nerve head antigens.

PURPOSE: The aim of this study was to analyze and compare the entire IgG autoantibody patterns against different ocular antigens (retina, optic nerve, and optic nerve head) in sera of glaucoma patients and healthy subjects. METHODS: Sixty-six patients were included in this study: healthy volunteers without any ocular disorders (CO, n=30), patients with primary open-angle glaucoma (POAG, n=19), and patients with normal-tension glaucoma (NTG, n=17). The sera were tested for antibodies against retinal, optic nerve, and optic nerve head tissues. Immunodetection was performed using 4-chloro-1-naphthol staining. The autoantibody patterns were digitized and subsequently analyzed by multivariate statistical techniques. RESULTS: All patients showed a complex repertoire of IgG antibodies against retinal, optic nerve, and optic nerve head antigens. The analysis of discriminance revealed a statistically significant differences between the patterns of all three groups. Our multivariate approach could quantify the differences in immunoreactivities of patient sera against the three antigens. The POAG group had the most significant difference against retinal antigens (P=0.0021) compared with the other antigens. In the NTG group the highest reactivity appeared against optic nerve head (P=0.00053) and optic nerve (P=0.0025). CONCLUSIONS: All groups showed different and complex antibody patterns against the three ocular tissues. These autoantibodies are highly specific for each patient group. The analysis of these patterns could provide further information about possible autoimmune mechanisms in the pathogenesis of glaucoma.

Giant papillary conjunctivitis--a closer look.

Giant papillary conjunctivitis is a clinical entity which is thought to be caused by a combination of mechanical, immunological and inflammatory mechanisms. This paper reviews the laboratory research data associated with giant papillary conjunctivitis.

Immunopathology of recurrent uveitis in spontaneously diseased horses.

Equine recurrent uveitis (ERU) is the most serious eye disease in horses worldwide. Despite the fact that ERU is generally considered to be immune mediated, a detailed description of the histopathology of the posterior part of ERU eyes is lacking. Here, we examined sections of paraffin-embedded eyes using histological and immunhistological methods. Twenty seven eyes of 20 horses with ERU and 30 eyes of 15 healthy control horses were included in this study. We could consistently demonstrate an involvement of the retina and the choroid in all examined eyes of horses with spontaneous ERU. In eyes with minimal histopathological changes, the infiltrates consisted almost exclusively of T-cells. Histopathological changes start with the destruction of the photoreceptor outer segments, which often leads to focal retinal detachment. In more severely affected eyes, there is additional disintegration of the ganglion cell layer and the inner nuclear layer. In almost all examined eyes, lymphoid follicle formation could be demonstrated. Typical localizations of these follicles were the iris stroma and the choroid underneath the transition zone of the retina without photoreceptor cells to the region containing photoreceptor cells. These follicles consist of a T-cell rich periphery with a small center of CD3-negative lymphocytes. In cases with extreme histopathological changes, the retinal architecture is widely disintegrated with massive infiltration of the retina, the choroid, and the ciliary body by several types of inflammatory cells. Necrotic remnants of the retina are end-stage findings and there is only a minor inflammatory infiltration left. This study provides clear evidence that the retina is involved in all stages of ERU. Inflammation is mainly driven by T-cells as T-cells were demonstrated in mild stages of the disease and are also the predominating cell type in all other stages of ERU.