Thermal Injury Induces Small Heat Shock Protein in the Optic Nerve Head In Vivo.

PURPOSE: To investigate the induction pattern of various heat shock protein (HSP) in the optic nerve head after thermal stress using transpupillary thermotherapy and to determine the dose-response relationship of thermal stress on the induction of various HSP. METHODS: The 810-nm diode laser with 50-µm spot size was aimed to the center of optic nerve head of right eye of Norway brown rats. First, the various exposure powers (100, 120, 140 mW) were used with the same exposure duration, 60 seconds, to investigate power dosing effect. Second, the various exposure durations (1, 2, 3, and 5 minutes) were applied under constant 100 mW laser power to investigate time dosing effect. Left eyes were served as controls. To quantify HSP expression, enucleation was performed at 24 hours after transpupillary thermotherapy. HSP 27 and αB-crystallin inductions in optic nerve head were examined with Western blot. RESULTS: All type of HSP was observed in normal state. After thermal injury, the expression of HSP 27 were increased, and the αB-crystallin were decreased. CONCLUSIONS: Induction pattern of each HSP in the optic nerve head were different after thermal injury. Some HSPs were induced or exhausted. Further research is needed on the characteristic functions and induction conditions of each HSP.

Effects of consumption of coffee, tea, or soft drinks on open-angle glaucoma: Korea National Health and Nutrition Examination Survey 2010 to 2011.

We sought to investigate the association between consumption of coffee, tea, or soft drinks and risk of open-angle glaucoma (OAG) among Koreans using nationwide population-based data. This cross-sectional survey was performed through the Korea National Health and Nutrition Examination Survey 2010 to 2011. Participants older than 19 years were included in the sample for analysis after excluding those with any missing data. The diagnosis of OAG was based on the International Society of Geographical and Epidemiological Ophthalmology criteria, and participants without glaucomatous optic neuropathy served as controls. The frequency of beverage consumption during the past 12 months was obtained through a questionnaire. Multivariate logistic regression models were used to determine the relationship between consumption of each type of beverage and prevalence of OAG. A total of 6,681 participants was included in the analysis. The prevalence of OAG was 4.4% (n = 323), including 5.4% (n = 169) among men and 3.5% (n = 154) among women. After adjusting for multiple covariates, coffee consumption was significantly associated with OAG, while no significant association was found between consumption of tea or soft drinks and OAG. Participants who drank coffee had a higher risk of having OAG compared with those who did not drink coffee (odds ratio [OR], 2.40; 95% confidence interval [CI], 1.22-4.72; p = 0.011). In sex-stratified analyses, the robust association of coffee consumption with OAG was observed in men (OR, 3.98; 95% CI, 1.71-9.25; p = 0.001) but not in women. Our results suggest that coffee consumption may affect the risk of OAG, particularly in men.

Ginkgo biloba extract and bilberry anthocyanins improve visual function in patients with normal tension glaucoma.

Ginkgo biloba extract (GBE) and anthocyanins are considered beneficial for various vascular diseases. This study was performed to evaluate the effect of GBE and anthocyanins on visual function in patients with normal tension glaucoma (NTG) based on the vascular theory of mechanisms of glaucomatous optic nerve damage. Retrospective analysis was carried out by a chart review of 332 subjects (209 men and 123 women) who were treated with anthocyanins (n=132), GBE (n=103), or no medication (control, n=97). Humphrey Visual Field (HVF) test, logarithm of the minimal angle of resolution best-corrected visual acuity (logMAR BCVA), intraocular pressure, blood pressure, and fasting blood glucose were determined before and after treatment. Complete ocular and systemic examinations were performed. The mean follow-up duration was 23.82±9.84 (range, 12-59) months; the mean anthocyanin treatment duration was 24.32±10.43 (range, 6-53) months, and the mean GBE treatment duration was 23.81±10.36 months (range, 6-59) months. After anthocyanin treatment, the mean BCVA for all eyes improved from 0.16 (±0.34) to 0.11 (±0.18) logMAR units (P=.008), and HVF mean deviation improved from -6.44 (±7.05) to -5.34 (±6.42) (P=.001). After GBE treatment, HVF mean deviation improved from -5.25 (±6.13) to -4.31 (±5.60) (P=.002). A generalized linear model demonstrated that the final BCVA was not affected by demographic differences among the groups. These results suggest that anthocyanins and GBE may be helpful in improving visual function in some individuals with NTG.

Thermal injury induces heat shock protein in the optic nerve head in vivo.

PURPOSE: To investigate the induction of heat shock protein (Hsp)70 in the optic nerve head by localized laser application in transpupillary thermotherapy (TTT). METHODS: TTT was performed on the right eye of Norwegian brown rats with an 810-nm diode laser installed on a slit lamp biomicroscope. The laser was aimed at the center of the optic nerve head with a 50-microm spot size. Various exposures (range, 60-200 mW) were used with an exposure duration of 60 seconds, and the various exposure durations (range, 1-5 minutes) were used with a power of 100 mW. Twenty hours after laser irradiation, immunohistochemical staining and Western blot analyses were performed. For morphologic analysis of the optic nerve head, confocal scanning laser ophthalmoscopy and scanning electron microscopy were performed. RESULTS: In the control eyes, Hsp70 was detected minimally in the optic nerve tissues by immunohistochemistry. After TTT, Hsp70 in the optic nerve tissue was induced more than in the control eyes. By Western blot, Hsp70 expression was found to increase progressively after TTT as the power was increased, but it also decreased slightly at powers >140 mW. The optimal setting of TTT without tissue damage was determined to be 100 mW for 60 seconds. CONCLUSIONS: Transpupillary laser irradiation of the optic nerve head induces Hsp70 expression. This result can be applied to the neuroprotective experiments in glaucoma by enhancement of a natural cytoprotective stress response.