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Glaucoma is one of the leading causes of bilateral blindness affecting nearly 8 million people worldwide. Glaucoma is characterized by a progressive loss of retinal ganglion cells (RGCs) and is often associated with elevated intraocular pressure (IOP). However, patients with normal tension glaucoma (NTG), a subtype of primary open-angle glaucoma (POAG), develop the disease without IOP elevation. The molecular pathways leading to the pathology of NTG and POAG are still unclear. Here, we describe the phenotypic characteristics of transgenic mice overexpressing wild-type (Wt) or mutated optineurin (Optn). Mutations E50K, H486R and Optn with a deletion of the first (amino acids 153-174) or second (amino acids 426-461) leucine zipper were used for overexpression. After 16 months, histological abnormalities were exclusively observed in the retina of E50K mutant mice with loss of RGCs and connecting synapses in the peripheral retina leading to a thinning of the nerve fiber layer at the optic nerve head at normal IOP. E50K mice also showed massive apoptosis and degeneration of entire retina, leading to approximately a 28% reduction of the retina thickness. At the molecular level, introduction of the E50K mutation disrupts the interaction between Optn and Rab8 GTPase, a protein involved in the regulation of vesicle transport from Golgi to plasma membrane. Wt Optn and an active GTP-bound form of Rab8 complex were localized at the Golgi complex. These data suggest that alternation of the Optn sequence can initiate significant retinal degeneration in mice.

Myocilin (MYOC) mutations are associated with juvenile- and adult-onset primary open-angle glaucoma (POAG). The purpose of this study was to determine whether MYOC gene mutations are associated with normal-tension glaucoma (NTG). The prevalence of MYOC mutations was determined in 80 Japanese NTG patients and 100 control subjects. In addition, the expression of mutant MYOC was determined by transforming COS-1 cells with five myocilin variants (R158Q, D208E, I360N, A363T, and I477S) and examining whether myocilin was present in the cultured cells and/or the culture medium by western blotting. Six different nucleotide sequence variants, R46Stop, R76K, R158Q, D208E, A488A, and one in the 3′ non-coding region, were identified in 80 NTG patients. Variants in codon 46 (R46Stop), codon 158 (R158Q), and codon 488 (A488A) were not found in the 100 normal controls. The frequency of other sequence changes (R76K, D208E, and 3′ non-coding) in NTG patients did not differ significantly from the frequencies in the control subjects. COS-1 cells transfected with the wild type, R158Q, or D208E variants secreted myocilin into the culture medium. On the other hand, the detected myocilin was significantly reduced in the medium of cells transfected with the I360N, A363T, or I477S variants that were previously identified as mutations for POAG. Definitive evidence of MYOC variants associated with NTG was not found.

PURPOSE Valsalva hemorrhagic retinopathy is characterized by retinal hemorrhages that develop after a Valsalva maneuver that consists of a forcible exhalation against a closed glottis, thereby creating a sudden increase in the intrathoracic or intraabdominal pressure. We present a patient who developed retinal and vitreous hemorrhages with multiple retinal nonperfused areas after extreme physical training with shouting on a mountainous area. This exercise was part of his training as a member of a Japanese traditional cheerleading team. METHOD Case presentation. RESULTS A 19-year-old man developed an acute decrease in the vision to 0.3 in his left eye after running on hilly roads at approximately 800 m while shouting fight songs for several hours. Ophthalmoscopy showed a fresh vitreous hemorrhage that covered the entire macula and was connected to the optic disk in the left eye. The vitreous hemorrhage spontaneously resolved and an intraretinal hemorrhage and nonperfused area emerged. His visual acuity returned to 1.2. CONCLUSION Prolonged, strenuous physical exertion with shouting during training exercises can lead to Valsalva hemorrhagic retinopathy. Several other factors, such as hot weather, altitude, and dehydration, may have played an additive role in increasing the venous pressure and hypoxia in the retinal vessels, which then caused the retinopathy.

Age-related macular degeneration (AMD) is a common cause of blindness in the elderly. Caucasian patients are predominantly affected by the dry form of AMD, whereas Japanese patients have predominantly the wet form of AMD and/or polypoidal choroidal vasculopathy (PCV). Although genetic association in the 10q26 (ARMS2/HTRA1) region has been established in many ethnic groups for dry-type AMD, typical wet-type AMD, and PCV, the contribution of the 1q32 (CFH) region seem to differ among these groups. Here we show a single nucleotide polymorphism (SNP) in the ARMS2/HTRA1 locus is associated in the whole genome for Japanese typical wet-type AMD (rs10490924: \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ p = 4.1 \times 10 ^{ - 4}$$\end{document}, OR = 4.16) and PCV (rs10490924: \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ p = 3.7 \times 10 ^{ -8}$$\end{document}, OR = 2.72) followed by CFH (rs800292: \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ p = 7.4 \times 10 ^{ -5}$$\end{document}, OR = 2.08; \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ p = 2.6 \times {10^{ - 4}} $$\end{document}, OR = 2.00), which differs from previous studies in Caucasian populations. Moreover, a SNP (rs2241394) in complement component C3 gene showed significant association with PCV (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ p = 2.5 \times {10^{ - 3}} $$\end{document}, OR = 3.47). We conclude that dry-type AMD, typical wet-type AMD, and PCV have both common and distinct genetic risks that become apparent when comparing Japanese versus Caucasian populations. Electronic supplementary material The online version of this article (doi:10.1007/s12177-009-9047-1) contains supplementary material, which is available to authorized users.

To study the frequency of five haplotypes previously reported in the complement factor H (CFH) gene for Japanese patients with age-related macular degeneration (AMD).Genomic DNA was isolated from peripheral blood samples taken from 96 Japanese AMD patients and 89 age-matched controls. All patients were diagnosed as having exudative (wet-type) AMD. The amplified polymerase chain reaction (PCR) products of CFH exons 2, 9, and 13, and intron 6 were analyzed by temperature gradient capillary electrophoresis (TGCE) and by direct sequencing. The haplotypes were identified, and their frequencies were calculated and compared with reported results.Five haplotypes were identified in the Japanese population including four already reported in the American population. The frequencies of these haplotypes were significantly different between Japanese and American in both control and case groups. The haplotype containing Y402H, which was previously reported to be associated with AMD, was only 4% in the control and case population, with a p value of 0.802. However, two other haplotypes were found as risk factors, which gave an increased likelihood of AMD of 1.9 and 2.5 fold (95% CI 1.12-3.69 and 1.42-6.38). One protective haplotype that decreased the likelihood of AMD by 1.6 fold (95% CI 0.26-0.67) was identified.The frequencies for five haplotypes previously identified were analyzed in a Japanese population with AMD. Four previously found haplotypes were identified and one additional haplotype was found. The frequencies of each haplotype were significantly different from that in found Americans affected with AMD. Two of the haplotypes were identified as risk factors and one was considered protective.

We investigated the expression of myocilin in the optic nerve head of porcine eyes by Western blotting and immunohistochemical staining. Myocilin was localized in the nucleus, centrosome, glial filament, mitochondria, and some parts of the cell membranes of the astrocytes. Myocilin was also detected at the edge-feet portion of the processes of astrocytes adjacent to the inner limiting membrane and blood vessel wall. The astrocytes are the major cell population in the optic nerve head, contributing to the architecture of the nerve axon and blood vessels. Therefore, myocilin gene mutation and change of myocilin protein are likely to affect the architecture of the optic nerve head and induce various forms of glaucomatous optic nerve damage.

PURPOSE. To determine the cDNA sequences and analyze the expression of porcine optineurin and myocilin in trabecular meshwork cells (TMCs) and astrocytes from the optic nerve head under normal and experimental conditions. METHODS. Both porcine optineurin and myocilin were cloned to determine the cDNA sequences. Porcine TMCs and astrocytes were isolated and treated with dexamethasone (500 nM) for 2 weeks, incubated under hypoxic conditions (7% O2) for 72 hours, or exposed to 33 mm Hg hydrostatic pressure for 72 hours. A 10% mechanical stretch for 24 hours was also performed on TMCs. The expression level of the optineurin and myocilin transcripts was analyzed by real-time quantitative PCR. RESULTS. The sequences of porcine optineurin and myocilin cDNA were determined, and the expression of both genes was confirmed in both TMCs and astrocytes. Amino acid sequences of porcine optineurin and myocilin were homologous to those of humans by 84% and 82%, respectively, and shared protein motifs and modification sites. The expression of myocilin mRNA by TMCs and astrocytes was increased by 8.0- and 5.5-fold, respectively, after exposure to dexamethasone. In contrast, the expression of optineurin was suppressed to 68% in TMCs and 48% in astrocytes after exposure to dexamethasone. A significant reduction of myocilin expression was observed after 72 hours of incubation under hypoxic conditions in both types of cells, whereas optineurin was not affected. Hydrostatic pressure for 72 hours and mechanical stretching for 24 hours had minimal affects on gene expression of both optineurin and myocilin. CONCLUSIONS. The high homology of porcine optineurin and myocilin to the comparable human genes indicates that pigs can be used to study changes in gene expression in hypertensive eyes. The alterations in expression of myocilin but not of optineurin under stress suggest that different mechanisms in the phenotype of glaucoma associated with the two genes are involved in development of glaucoma. (Invest Ophthalmol Vis Sci. 2004;45:2652‐2659) DOI:10.1167/iovs.03-0572