Driving self-restriction and motor vehicle collision occurrence in glaucoma.

PURPOSE: To confirm that subjects with primary open-angle glaucoma (POAG) who avoid driving in high-risk situations are less likely to be involved in motor vehicle collisions (MVCs) than those who do not. METHODS: This study evaluated 252 consecutive Japanese aged between 40 and 85 years with POAG. All participants were requested to answer a questionnaire on their driving habits, including self-restriction in driving at night, in rain, in fog, on freeways, and lane changing, and history of MVCs. Those who reported restricting their driving in one or more ways constituted the self-restriction group, and those who reported no self-restriction made up the no-restriction group. The prevalence of MVCs and the crash rate (number of MVCs/10,000 km driven) were compared between the two groups. The association between prevalence of MVCs and the number of driving self-restrictions was also evaluated. RESULTS: The association between driving self-restriction and MVCs was observed among the male subjects, not among the female subjects. Among the male subjects, the prevalence of MVCs was significantly higher in the no-restriction group than in the self-restriction group (no-restriction group, 33/107 = 30.8%; self-restriction group, 9/66 = 13.6%, p = 0.01). The crash rate was also significantly higher in the no-restriction group (no-restriction group, 1.4 ± 0.8; self-restriction group, 0.4 ± 0.3, average ± SE, p = 0.01). No restriction was significantly associated with MVCs (multivariable-adjusted odds ratios, 2.43 [95% confidence interval, 1.03 to 5.73]). The number of driving self-restrictions was also associated with MVCs (multivariable-adjusted odds ratios, 0.41 [95% confidence interval, 0.18 to 0.99], per one increment of self-restriction). CONCLUSIONS: Driving self-restriction may be associated with a reduced prevalence of MVCs in men with POAG.

Visualization of gaseous monoxide reception by soluble guanylate cyclase in the rat retina.

Immunohistochemistry using novel monoclonal antibodies (mAbs) allowed us to uncover tissue activities of soluble guanylate cyclase (sGC) fine tuned by NO and CO. Upon NO and CO applications in vitro, purified sGC increased the affinity to mAb3221 by 100- and 10-fold, respectively, but not to mAb28131. Immunohistochemistry for gas-generating enzymes revealed that NO occurred in amacrine, bipolar, and Müller's glia cells (MGCs), whereas CO was derived mostly from heme oxygenase (HO)-2 in MGCs. Basal sGC immunoreactivities in vivo to mAb3221 but not to mAb28131 were enhanced by injecting L-arginine and attenuated by blocking NO synthases, suggesting the ability of the former mAb to sense NO. Comparison of mAb-assisted immunohistochemistry suggested that sGC activities were enhanced by zinc protoporphyrin-IX, an HO inhibitor, and repressed completely by blocking NO. However, suggested roles of CO played in situ varied among different retinal layers. In inner plexiform and inner nuclear layers located in the proximity of the cellular NO sources, CO serves as a simple inhibitor of local sGC, while playing roles in housekeeping sGC activation in external limiting membrane standing far from them. These results suggest that CO generated in MGCs is a diffusible gas mediator regulating sGC in both autocrine and paracrine manners.

Glaucomatous visual field defect severity and the prevalence of motor vehicle collisions in Japanese: a hospital/clinic-based cross-sectional study.

Purpose. This study examined the association between the severity of visual field defects and the prevalence of motor vehicle collisions (MVCs) in subjects with primary open-angle glaucoma (POAG). Methods. This is a cross-sectional study. Japanese patients who have had driver's licence between 40 and 85 years of age were screened for eligibility. Participants answered a questionnaire about MVCs experienced during the previous 5 years. Subjects with POAG were classified as having mild, moderate, or severe visual field defect. We evaluated associations between the severity of POAG and the prevalence of MVCs by logistic regression models. Results. The prevalence of MVCs was significantly associated with the severity of POAG categorized by worse eye MD (control: 30/187 = 16.0%; mild POAG: 17/92 = 18.5%; moderate POAG: 14/60 = 23.3%; severe POAG: 14/47 = 29.8%; P = 0.025, Cochran-Armitage trend test). Compared to the control group, the adjusted OR for MVC prevalence in subjects with mild, moderate, or severe POAG in the worse eye was 1.07 (95% CI: 0.55 to 2.10), 1.44 (95% CI: 0.68 to 3.08), and 2.28 (95% CI: 1.07 to 4.88). Conclusions. There is a significant association between the severity of glaucoma in the worse eye MD and the prevalence of MVCs.

Simple and inexpensive software designed for the evaluation of color.

PURPOSE: To report on new software that was specially designed to evaluate color. METHODS: Software development and observational case report. Each pixel on a computer screen is composed of three colors: red, green, and blue (RGB). Our software analyzes the intensity of each RGB component in a specific area chosen by the user. To test our software, we evaluated the color level of the irises of a subject, which became darker as a side effect of Xalatan (latanoprost; Pharmacia Corporation, Peapack, New Jersey) eyedrops. RESULT: We successfully expressed the level of the color of the iris by number. CONCLUSION: This software measures the color of a lesion and thereby provides an objective evaluation of color. The software we developed is downloadable, without cost, from http://www.isao.com.

Multivariable logistic regression model: a novel mathematical model that predicts visual field sensitivity from macular ganglion cell complex thickness in glaucoma.

PURPOSE: To design a mathematical model that can predict the relationship between the ganglion cell complex (GCC) thickness and visual field sensitivity (VFS) in glaucoma patients. DESIGN: Retrospective cross-sectional case series. METHOD: Within 3 months from VFS measurements by the Humphrey field analyzer 10-2 program, 83 eyes underwent macular GCC thickness measurements by spectral-domain optical coherence tomography (SD-OCT). Data were used to construct a multiple logistic model that depicted the relationship between the explanatory variables (GCC thickness, age, sex, and spherical equivalent of refractive errors) determined by a regression analysis and the mean VFS corresponding to the SD-OCT scanned area. Analyses were performed in half or 8 segmented local areas as well as in whole scanned areas. A simple logistic model that included GCC thickness as the single explanatory variable was also constructed. The ability of the logistic models to depict the real GCC thickness/VFS in SAP distribution was analyzed by the χ2 test of goodness-of-fit. The significance of the model effect was analyzed by analysis of variance (ANOVA). RESULTS: Scatter plots between the GCC thickness and the mean VFS showed sigmoid curves. The χ2 test of goodness-of-fit revealed that the multiple logistic models showed a good fit for the real GCC thickness/VFS distribution in all areas except the nasal-inferior-outer area. ANOVA revealed that all of the multiple logistic models significantly predicted the VFS based on the explanatory variables. Although simple logistic models also exhibited significant VFS predictability based on the GCC thickness, the model effect was less than that observed for the multiple logistic models. CONCLUSIONS: The currently proposed logistic models are useful methods for depicting relationships between the explanatory variables, including the GCC thickness, and the mean VFS in glaucoma patients.

The association between visual field defect severity and fear of falling in primary open-angle glaucoma.

PURPOSE: To determine if glaucomatous visual field defect severity is associated with fear of falling. METHODS: This is a cross-sectional study. A total of 387 consecutive subjects with POAG were enrolled in this study along with 293-ocular disease-free control subjects, who were screened at the same institutions. We defined mild POAG as MD of -6 dB or better, moderate POAG as MD of -6 to -12 dB, and severe POAG as MD of -12 dB or worse in the better eye. All participants were requested to answer a questionnaire on fear of falling. Associations between POAG severity and the prevalence of fear of falling were evaluated with the Cochran-Armitage trend test. Multivariable factors including age-adjusted odds ratios (ORs) for the prevalence of fear of falling and 95% confidence intervals (CIs) were evaluated with logistic regression models. RESULTS: The prevalence of fear of falling was 35/293 (11.9%) in the control group, 38/313 (12.1%) in the mild POAG group, 12/48 (25.0%) in the moderate POAG group, and 6/26 (23.1%) in the severe POAG group, and the trend was statistically significant (P = 0.028 Cochran-Armitage trend test). The adjusted ORs for prevalence in the mild, moderate, and severe POAG groups compared with that in the control group were 1.44 (95% CI: 0.83-2.51), 2.33 (95% CI: 1.00-5.44), and 4.06 (95% CI: 1.39-11.90), respectively. CONCLUSIONS: Among patients with POAG, the severity of visual field defects is associated with fear of falling. (http://www.umin.ac.jp/ctr/index.htm number, UMIN000005574.).