Association study of genetic variants on chromosome 7q31 with susceptibility to normal tension glaucoma in a Japanese population.

The caveolin 1 to caveolin 2 (CAV1-CAV2) gene region on chromosome 7q31 has been reported to be associated with susceptibility to primary open angle glaucoma (POAG) and normal tension glaucoma (NTG) in previous studies. We investigated whether genetic variants in the CAV1-CAV2 region are associated with NTG in Japanese patients. Two hundred and ninety-two Japanese patients with NTG and 352 Japanese healthy controls were recruited. We genotyped three single-nucleotide polymorphisms; that is, rs1052990, rs4236601, and rs7795356, in the CAV1-CAV2 gene region and assessed the allelic diversity among cases and controls. The frequency of the minor allele (G) of rs1052990 was significantly decreased in NTG cases compared with controls (P=0.014, OR=0.71), whereas NTG or POAG cases had a significantly higher frequency of the allele than controls in previous studies. Conversely, rs7795356 did not show any significant association with NTG cases, and rs4236601 was monomorphic in the Japanese study population. Our findings did not correspond with previous positive results, suggesting that CAV1-CAV2 variants studied in the present study are not important risk factors for NTG susceptibility in all populations. Further studies are needed to elucidate the possible contribution of the CAV1-CAV2 region to the development of glaucoma.

Central 10-degree visual field change following trabeculectomy in advanced open-angle glaucoma.

PURPOSE: To prospectively examine changes in the central visual field (VF) in patients with advanced open-angle glaucoma (OAG) with advanced late stage after trabeculectomy for 12 months. DESIGN: Prospective interventional case series. METHODS: In all, 27 eyes of 27 OAG patients at a single center with a best-corrected visual acuity (BCVA) of ≥40/200 and a mean total deviation of test locations of the 10-2 program of the Humphrey VF analyzer of ≤-20 dB preoperatively were enrolled. Intraocular pressure (IOP), VF parameters of the 10-2 program, and BCVA were examined for 12 months after trabeculectomy with mitomycin C. Slopes of VF parameters and their correlation with presumed risk factors were studied. RESULTS: IOP decreased from 19.7±5.8 to 9.7±2.6 mm Hg (P<0.001) over postoperative 1 year. The slopes of all VF parameters did not significantly differ from zero (P>0.33), and none of the presumed factors significantly correlated with the slopes of those parameters (P>0.14). There were two eyes (7%) and one eye (4%) with ≥2 lines of deterioration in BCVA (decimal fraction) at 1 and 12 months, respectively, after surgery with no apparent causes. CONCLUSIONS: Trabeculectomy resulted in little change in the central 10-degree VF, but significant decrease in BCVA without apparent causes might occur approximately 5% of the cases.

Investigation of the association between the GLC3A locus and normal tension glaucoma in Japanese patients by microsatellite analysis.

PURPOSE: To investigate whether the GLC3A locus harboring the CYP1B1 gene is associated with normal tension glaucoma (NTG) in Japanese patients. MATERIALS AND METHODS: One hundred forty-two Japanese patients with NTG and 101 Japanese healthy controls were recruited. Patients exhibiting a comparatively early onset were selected as this suggests that genetic factors may show stronger involvement. Genotyping and assessment of allelic diversity was performed on 13 highly polymorphic microsatellite markers in and around the GLC3A locus. RESULTS: There were decreased frequencies of the 444 allele of D2S0416i and the 258 allele of D2S0425i in cases compared to controls (P = 0.022 and P = 0.034, respectively). However, this statistical significance disappeared when corrected (Pc > 0.05). We did not find any significant association between the remaining 11 microsatellite markers, including D2S177, which may be associated with CYP1B1, and NTG (P > 0.05). CONCLUSIONS: Our study showed no association between the GLCA3 locus and NTG, suggesting that the CYP1B1 gene, which is reportedly involved in a range of glaucoma phenotypes, may not be an associated factor in the pathogenesis of NTG.

Initial trabeculectomy with mitomycin C in eyes with uveitic glaucoma with inactive uveitis.

PURPOSE: To analyse clinical outcomes of trabeculectomy with mitomycin C (MMC) in eyes with uveitic glaucoma (UG) with inactive uveitis and compare them to those in eyes with primary open-angle glaucoma (POAG). DESIGN: Retrospective non-randomized comparative interventional case series. METHODS: A total of 53 eyes with UG and 80 eyes with POAG that received MMC trabeculectomy as an initial ocular surgery with average follow-up of 5.4 years were reviewed retrospectively. The intraocular pressure (IOP) control and persistence of filtering bleb were analysed using the Kaplan-Meier life-table method based on two definitions of successful IOP control, ie complete success (IOP

Atypical retardation pattern in measurements of scanning laser polarimetry and its relating factors.

PURPOSE: To assess the prevalence of atypical retardation pattern (ARP) in scanning laser polarimetry (SLP) with variable corneal compensation (VCC) and enhanced corneal compensation (ECC), and to evaluate the factors relating to typical scan score (TSS). METHODS: Measurements of SLP-VCC, SLP-ECC, and the Humphrey field analyzer (HFA) were performed in 105 normal subjects and 82 open-angle glaucoma (OAG) patients. ARP was defined as an SLP image with TSS<80. RESULTS: Prevalence of ARP with SLP-VCC was 13.3 and 14.6% in normal and OAG eyes, respectively, and that with SLP-ECC (2.9% and 1.2%) was lower than SLP-VCC (P<0.009). TSS with SLP-VCC was significantly correlated with age (partial correlation coefficient (PCC)=-0.22, P=0.003) and refractive error (PCC=0.26, P<0.001) after adjusting for each other. TSS with SLP-ECC was significantly correlated with neither age nor refractive error (PCC=-0.02, P=0.788; PCC=0.10, P=0.177, respectively). In OAG eyes, mean deviation (MD) of HFA was significantly correlated with TSS with SLP-VCC and SLP-ECC (PCC=0.35, P=0.001; PCC=0.23, P=0.039, respectively). In SLP-VCC, MD was significantly correlated with retinal nerve fibre layer (RNFL) thickness only after excluding eyes with ARP (P<0.001). CONCLUSIONS: ARP in SLP-VCC measurements was found in more than 10% of normal or glaucomatous eyes, and TSS was significantly lower in older subjects, more myopic eyes, or eyes with more advanced glaucomatous damage. The presence of ARP disturbs the accuracy of RNFL thickness measurement by SLP-VCC. In SLP-ECC measurements, prevalence of ARP was considerably lower and TSS was not affected by age or refractive error, suggesting the advantages of ECC in clinical practices.

A Na+/Ca2+ exchanger isoform, NCX1, is involved in retinal cell death after N-methyl-D-aspartate injection and ischemia-reperfusion.

We investigated the expression of Na(+)/Ca(2+) exchanger (NCX) and the functional role of NCX in retinal damage by using NCX1-heterozygous deficient mice (NCX1(+/-)) and SEA0400 (2-[4-[(2,5-difluorophenyl)methoxy] phenoxy]-5-ethoxyaniline), a selective NCX inhibitor in vivo. We also examined the role of NCX in oxygen-glucose deprivation (OGD) stress with a retinal ganglion cell line (RGC-5) cell culture in vitro. The expression of NCX1 was confirmed and entirely localized in retina by immunoblotting and immunohistochemistry, respectively. NCX1(+/-) mice possessed significant protection against retinal damage induced by intravitreal injection of N-methyl-D-aspartate (NMDA). SEA0400 at 3 and 10 mg/kg significantly reduced NMDA- or high intraocular pressure-induced retinal cell damage in mice. Furthermore, SEA0400 reduced the number of TUNEL (terminal deoxynucleotidyl transferase dUTP nick-end labeling)-positive cells and the expression of phosphorylated mitogen-activated protein kinases (ERK1/2, JNK, p38) induced by NMDA injection. In RGC-5, SEA0400 at 0.3 and 1 microM significantly inhibited OGD-induced cell damage. OGD-induced cell damage was aggravated by ouabain (a Na(+),K(+)-ATPase inhibitor) at 100 microM, and this increased damage was significantly reduced by SEA0400 at 1 microM. In conclusion, these results suggest that NCX1 may play a role in retinal cell death induced by NMDA and ischemia-reperfusion.

Topical phenylephrine decreases blood velocity in the optic nerve head and increases resistive index in the retinal arteries.

PURPOSE: To investigate the effects of topical phenylephrine on circulation in the optic nerve head (ONH), posterior choroids, or retina in rabbits and healthy humans. METHODS: Tissue blood velocity in the ONH and posterior choroid was measured using the laser speckle method as normalized blur (NB(ONH) and NB(CH)) in 28 anaesthetized albino rabbits. NB and intraocular pressure (IOP) in both eyes were measured for 180 min after unilateral single instillation of 5% phenylephrine and contralateral physiological saline as a control. In 11 normal volunteers aged 26.0+/-2.7 years, NB(ONH) was measured for 180 min after unilateral three drops of 5% phenylephrine and contralateral physiological saline in a double-masked manner. In the other 17 normal volunteers aged 25.5+/-2.4 years, blood velocity and blood flow in a major branch of the central retinal artery were measured using the laser Doppler blood flow metre and IOP and systemic circulatory parameters were monitored in similar fashion. Analysis of variance was applied for intergroup comparisons. RESULTS: NB(ONH) and NB(CH) decreased significantly only in the phenylephrine-treated eyes in rabbits by maximum of 9 and 20%, respectively (P=0.0046 and 0.0009), despite IOP decrease. In humans, NB(ONH) decreased significant by maximum of 13% (P=0.0047) and resistive index in the retinal arteries increased by 10% (P=0.0067) unilaterally; whereas IOP, diameter, blood velocity, or blood flow of the arteries was not significantly changed. CONCLUSION: Topical phenylephrine could exert a significant unfavourable effect on circulation in the ONH, choroidal tissue, and retinal arteries in rabbits and normal young humans.

Population-based prevalence of optic disc haemorrhages in elderly Japanese.

PURPOSE: To estimate the population-based prevalence of disc haemorrhages (DHs) in an elderly Japanese population and evaluate related factors including optic disc morphology. PATIENTS AND METHODS: Colour fundus photographs were taken during the screening examination of the Tajimi Study, during which 3021 of 3870 eligible residents of the city aged 40 years or older were screened (response rate, 78.1%). All fundus photographs were graded by one masked examiner to determine the presence of DHs. RESULTS: Good quality fundus photographs were available for both eyes of 2761 subjects. DHs were found in at least one eye of 34 subjects (1.2%; 95% confidence interval (CI) 0.8-1.6%). The prevalence was 14.0% (95% CI, 8.0-19.9%), 9.7% (2.9-16.6%), and 0.4% (0.1-0.6%) in subjects with definitive glaucoma, glaucoma suspects, and subjects without glaucoma, respectively. Logistic regression analyses indicated that DHs were associated with glaucoma (P<0.001), glaucoma suspects (P<0.001), and older age (P=0.032). No Heidelberg Retina Tomograph parameters differed between subjects with and without DHs. CONCLUSIONS: The prevalence of DHs was 1.2% in an elderly Japanese population, which was similar to other population studies. In addition to glaucoma, older age was associated with higher prevalence of DHs.

Penetrating keratoplasty for bullous keratopathy after trabeculectomy.

PURPOSE: To evaluate the results of penetrating keratoplasty (PK) in eyes with bullous keratopathy having previously undergone trabeculectomy. METHODS: We reviewed medical records of patients that had undergone PK for bullous keratopathy having previously undergone trabeculectomy. A total of 34 eyes in 34 patients were included in the study. As a control group, we reviewed the medical records of 26 eyes in 26 patients that had no history of glaucoma and who had undergone PK for bullous keratopathy in the same period at the same institutes. Kaplan-Meier survival analysis was performed to estimate the cumulative probability of successful intraocular pressure (IOP) control, immune reaction-free graft, and graft survival. RESULTS: Visual acuity improved by more than two lines in 30-34 eyes (88%). Log-rank tests showed a statistically significant difference in the cumulative probability of successful IOP control between eyes with functioning blebs and eyes with non-functioning blebs (P=0.0005), but not between the experimental subjects of 34 eyes and the control group (P=0.198). The log-rank test did not show statistically significant differences in the cumulative probability of immune reaction-free grafts and graft failure between the subjects and the control group and between eyes with functioning blebs and eyes with non-functioning blebs. CONCLUSION: The outcomes for PK in bullous keratopathy are good for patients having previously undergone trabeculectomy. Surgical procedures should be performed before PK in eyes with non-functioning blebs even when IOP is controllable with medication.

Ocular and systemic factors related to intraocular pressure in Japanese adults: the Tajimi study.

BACKGROUND: As intraocular pressure (IOP) and age are consistent risk factors of glaucoma, it is of special interest to know the association between IOP and possibly relating factors including age in Japan where a high prevalence of normal-tension glaucoma has been reported. The aim of this report was to evaluate the distribution of and factors related to applanation IOP in a population-based study in Japan. METHODS: A randomly sampled group of 3021 residents (response rate 78.1%) of Tajimi City, aged 40 years or older, underwent screening examinations including measurements of IOP with Goldmann applanation tonometry and central corneal thickness. RESULTS: Among right eyes without glaucoma, suspected glaucoma or other disorders which could affect correct IOP measurements, IOP averaged 14.6 (SD 2.7) and 14.5 (2.5) mm Hg in men and women, respectively, with no significant intergender difference (p = 0.342). Multiple regression analyses revealed that age was significantly negatively correlated with IOP (non-standardised beta (B) = -0.020/year, p = 0.0001). Higher body mass index (B = 0.14/BMI, p<0.0001), higher mean blood pressure (B = 0.022/mm Hg, p<0.0001), history of diabetes (p = 0.0019), thicker cornea (B = 0.014/microm, p<0.0001), higher myopia (B = 0.055/dioptres, p = 0.0043) and steeper corneal curvature (B = -0.72/mm, p = 0.0002) were also significantly correlated with higher IOP. CONCLUSIONS: In an adult Japanese population, applanation IOP averaged 14.5 mm Hg and was negatively correlated with age after adjusting for other related factors. A positive correlation between IOP and myopia was found.

Performance of GDx VCC in eyes with peripapillary atrophy: comparison of three circle sizes.

PURPOSE: A scanning laser polarimetry (GDx VCC) equips three different sized measurement circles. In eyes with peripapillary atrophy (PPA), the GDx measurement becomes inaccurate when the circle falls on PPA. The aim of this study was to evaluate performance of the three circles of GDx measurement in eyes with PPA. METHODS: Three different sized circles were compared regarding frequency of PPA, which fell on each circle in 282 open-angle glaucoma (OAG) eyes, reproducibility of GDx parameters in 24 normal and 22 OAG eyes, and ability to detect glaucoma in 50 normal and 50 OAG eyes. RESULTS: PPA was observed in 230 (82%) of 282 OAG eyes. PPA fell on the small circle (default setting), medium, and large circles in 119 (43%), 38 (14%), and 12 (4%) of the 280 OAG eyes. Reproducibility of GDx parameters was not significantly different among three circles in normal eyes (P>0.05), whereas coefficients of reproducibility of TSNIT average (P=0.006) and superior average (P=0.035) were smaller in the smaller circles in OAG eyes. GDx parameters significantly correlated (P<0.001), but were significantly different (P<0.05) between the small and medium circles. The area under receiver operating characteristic curves for dividing OAG from normal eyes using GDx parameters was similar between the small and medium circles. CONCLUSIONS: If the medium circles were used, obstructing influences of PPA on GDx measurement could be avoided more often in Japanese OAG eyes with similar reproducibility and comparable ability to detect glaucoma compared to those with the default small circle.

Optic disc topographic parameters measured in the normal cynomolgus monkey by confocal scanning laser tomography.

AIM: To study optic disc topographic parameters in normal cynomolgus monkeys by Heidelberg retina tomograph (HRT). METHODS: 12 optic disc topographic parameters were investigated in 36 normal eyes in 18 male monkeys. Mean (SD) and interocular differences were obtained for each parameter from three independent measurements made during a 1 week period. Correlations among the topographic parameters were analysed, too. RESULTS: No significant differences between right and left eyes were detected for any topographic parameters. Disc area, rim area, and height variation contour showed smaller right-left differences than other parameters. The coefficients of variation for rim area, height variation contour, rim volume, mean cup depth, maximum cup depth, mean retinal nerve fibre layer (RNFL) thickness, and RNFL cross section area were less than 10% (for rim area, less than 5%). Rim area and height variation contour showed relatively weak interrelations and neither showed a correlation with disc area. CONCLUSION: For evaluating time related changes in the optic disc by HRT in monkeys, rim area and height variation contour might be useful parameters because coefficients of variation and right-left differences were lower than for other parameters and because these parameters showed weak interrelations and no correlation with disc area.

Topical application of autologous serum for the treatment of late-onset aqueous oozing or point-leak through filtering bleb.

PURPOSE: To evaluate the efficacy of topical autologous serum application to stop aqueous oozing or point-leak through filtering bleb after trabeculectomy. PATIENTS AND METHODS: A total of 21 consecutive eyes with oozing and 21 eyes with a point-leak through a functional bleb after trabeculectomy with 5-fluorouracil or mitomycin C were enrolled in this randomized, case-control study. In eyes randomly assigned to the serum group, an antibiotic and the autologous serum, which was sterilely diluted to 20% with physiological saline, were topically applied four times a day for up to 12 weeks. In eyes assigned to the control group, the antibiotic alone was applied according to the same protocol. Intraocular pressure (IOP) and the presence of oozing or a point-leak were tested before and every 2 weeks after starting the treatments. RESULTS: In the serum and control groups, oozing stopped in 62.5 and 0% of eyes, respectively (P=0.003), and point-leaks stopped in 27.3 and 18.2%, respectively (P>0.9). IOP significantly increased from 10.0+/-3.2 (mean+/-standard deviation) to 11.8+/-3.3 mmHg in eyes in which oozing stopped (P=0.066), and from 11.4+/-2.7 to 15.4+/-2.3 mmHg in eyes in which a point-leak stopped (P=0.042). CONCLUSIONS: Autologous serum application was significantly effective to stop aqueous oozing but not point-leaks. Stopping oozing or point-leaks was significantly associated with an increase in IOP.

Allergens in Japanese patients with allergic conjunctivitis in autumn.

PURPOSE: The purpose of the current study is to evaluate the relation between various specific class E immunoglobulins (IgE) in the serum and allergic conjunctivitis in autumn. METHODS: Total IgE and specific IgE to 12 inhalant allergens were measured using the CAP system in 32 patients with allergic conjunctivitis in spring (spring group), 27 patients with allergic conjunctivitis in autumn (autumn group), and 40 healthy volunteers (control group). RESULTS: Specific IgE levels caused by house dust, Dermatophagoides pteronyssinus, and orchard grass were higher in the autumn group than in the spring group. The highest positivity rate for a specific allergen was 51.9% for house dust, followed by D. pteronyssinus(48.1%) in the autumn group, while the highest rate was 68.8 % for cedar pollen, followed by cypress pollen (59.4%) in the spring group. Correlation analysis showed that house dust was significantly correlated with animal epithelia, D. pteronyssinus, acarus, and Alternaria tenuis in the autumn group (P<0.001). CONCLUSIONS: These results suggest that house dust is the main cause of allergic conjunctivitis during autumn. In spring, cypress pollen is the largest cause of allergic conjunctivitis, while indoor allergens such as house dust, animal epithelia, D. pteronyssinus, and acarus are not causative allergens in Japan.

Development and progression of diabetic retinopathy in patients with Type 1 diabetes who are positive for GAD autoantibody.

AIMS: To investigate the relationship between autoantibodies to glutamic acid decarboxylase (GAD) and proliferative diabetic retinopathy (PDR) to assess the role of autoimmunity in retinopathy. METHODS: Patients with Type 1 diabetes for more than 10 years who had been diagnosed under age 30 (13-28 years) were studied. They were classified into three groups. The PDR group consisted of 22 patients, the pre-PDR group was 26 patients, while the non-DR group was 32 patients who had Type 1 diabetes without retinopathy. Blood was collected to measure autoantibodies to GAD, and the relationship between PDR and GAD positivity was investigated in a cross-sectional study. RESULTS: The highest positivity rate of GAD autoantibodies was 50.0% in the non-DR group, followed by the pre-PDR group (30.8%) and the PDR group (18.2%). CONCLUSIONS: Production or existence of GAD autoantibodies may contribute to the prevention of retinopathy.

A three-year prospective, randomized and open comparison between latanoprost and timolol in Japanese normal-tension glaucoma patients.

PURPOSE: To compare the longitudinal effects of treatment on intraocular pressure (IOP) and visual field performance in Japanese normal-tension glaucoma (NTG) between latanoprost and timolol. PATIENTS AND METHODS: This is an open-label, randomized, study. A total of 62 NTG patients were prospectively, consecutively enrolled. All study subjects were randomly assigned to 0.005% latanoprost instillation once daily in the morning or 0.5% timolol instillation twice daily for a prospective 3-year follow-up, and underwent a routine ocular examination every month. Automated perimetry was performed every 6 months using Humphrey field analysers. Stereophotographs of optic discs were also obtained every 6 months. RESULTS: Percentage of IOP reduction or the magnitude of IOP reduction showed no intergroup differences either at any time point (13-15%). In the visual field, the estimated rate of change in the MD value (dB/year) was -0.34+/-0.17 (SE) for the latanoprost group, and -0.10+/-0.18 (SE) for the timolol group. The estimated rate of change in MD showed no significant difference from zero in both groups, and there were no statistical intergroup differences. No changes in the optic nerve head topography in the vertical cup-to-disc ratio and rim area measured by image-analysis techniques were observed in either group. There were no patients who dropped out due to the side effects of treatment regimens. CONCLUSION: Both latanoprost and timolol single treatments reduced IOP by 13-15% at their trough effects for 3 years in Japanese NTG patients; both showed similar effects on visual field performance.

Phenotype of cytochrome P4501B1 gene (CYP1B1) mutations in Japanese patients with primary congenital glaucoma.

AIM: To investigate the phenotypes associated with cytochrome P4501B1 gene (CYP1B1) mutations in Japanese patients with primary congenital glaucoma (PCG). METHODS: 66 Japanese patients with PCG were screened for sequence mutations in the CYP1B1 gene using single strand conformation polymorphism analysis followed by automated DNA sequencing. 11 cases had a CYP1B1 mutation in both alleles (the mutation group) and 21 cases did not have a CYP1B1 mutation (the "no mutation" group). The clinical features, such as age of onset, sex, intraocular pressure, and Descemet's membrane rupture, of the two groups were compared. RESULTS: The clinical symptoms and signs did not differ for the two groups. The mean age at onset was 1.7 months in the mutation group and 3.1 months in the no mutation group, and the male:female ratio was 6:5 in the mutation group and 19:2 in the no mutation group. Both of these differences were statistically significant. CONCLUSIONS: In clinically diagnosed cases of PCG, a subgroup shows a CYP1B1 gene mutation. Age at onset was earlier in PCG patients with CYP1B1 mutations than in patients without mutations. Women were more prevalent among patients with mutations than those without mutations.

Hyaluronan synthase in trabecular meshwork cells.

BACKGROUND/AIMS: Hyaluronan is present in the trabecular meshwork where it is involved in the pathophysiology of aqueous outflow environment. In this study, the expression and regulation of hyaluronan synthase (HAS), which is the enzyme synthesising hyaluronan, in trabecular meshwork cells were investigated. METHODS: Cultured bovine trabecular meshwork cells (BTMCs) were used. HAS expression in BTMCs was examined by RT-PCR. The effects of transforming growth factor beta (TGF-beta) and platelet derived growth factor BB (PDGF-BB) on HAS expression in BTMCs were examined by quantitative RT-PCR. The HAS2 expression by TGF-beta and PDGF-BB at the protein level was also confirmed immunohistochemically. The production of hyaluronan from BTMCs was detected by high performance liquid chromatography (HPLC). RESULTS: Three HAS isoforms were expressed in BTMCs at the mRNA level. Among HAS isoforms, only the expression of HAS2 mRNA was increased by the administration of TGF-beta or PDGF-BB. HAS2 upregulation by these growth factors was also confirmed at the protein level. Further, hyaluronan production from BTMCs was stimulated by TGF-beta or PDGF-BB. CONCLUSION: Expression of HAS in trabecular meshwork may maintain the hyaluronan content in the aqueous outflow pathway. Its production is regulated by TGF-beta and PDGF-BB. The regulation of the expression of HAS in trabecular meshwork might be useful for modulating the aqueous outflow environment.