Biometric gonioscopy and the effects of age, race, and sex on the anterior chamber angle.

AIM: To utilise a novel method for making measurements in the anterior chamber in order to compare the anterior chamber angles of people of European, African, and east Asian descent aged 40 years and over. METHODS: A cross sectional study on 15 people of each sex from each decade from the 40s to the 70s, from each of three racial groups-black, white, and Chinese Singaporeans. Biometric gonioscopy (BG) utilises a slit lamp mounted reticule to make measurements from the apparent iris insertion to Schwalbe's line through a Goldmann one mirror goniolens. The main outcome measures were BG measurements of the anterior chamber angle as detailed above. RESULTS: There was no significant difference in angle measurement between black, white, and Chinese races in this study. However, at younger ages people of Chinese race appeared to have deeper angles than white or black people, whereas the angles of older Chinese were significantly narrower (p = 0.004 for the difference in slope of BG by age between Chinese and both black and white people). CONCLUSION: The failure to detect a difference in angle measurements between these groups was surprising, given the much higher prevalence of angle closure among Chinese. It appears that the overall apparent similarity of BG means between Chinese and Western populations may mask very different trends with age. The apparently more rapid decline in angle width measurements with age among Chinese may be due to the higher prevalence of cataract or "creeping angle closure." However, longitudinal inferences from cross sectional data are problematic, and this may represent a cohort phenomenon caused by the increasing prevalence of myopia in the younger Singaporean population.

[Thrombocyte counts in TMB (Tryon Maze Brights) and TMD (Tryon Maze Dulls) rats following warfarin (author's transl)]. / Thrombozytenzahl bei tmb (tyron-maze-brights)- und tmd (tryon-maze-dulls)-ratten nach warfain.

A dosage of 3 mg Warfarin/kg body weight causes a highly significant increase in the number of platelets both in TMB (Tryon maze brights) and TMD (Tryon maze dulls) rats. Different "intelligence levels" show no effect on this increase. In condition of rest the number of platelets is significantly higher in TMD rats than in TMB animals. With regard to a hypothetical relationship between the number of platelets and the amount of circulating and urinary catecholamines the results suggest a similar relationship in conditions of rest as can be shown in emotive (e+) and nonemotive (e--) Wistar rats as well as a varying reaction to stress -- different levels of "intelligence" and anxiety provided.