The characteristics of glaucoma in Japanese Americans.

Objective: To determine the proportions of glaucoma subtypes and risk factors for glaucoma in a large Japanese American clinic population.
Methods: Medical records of patients of Japanese descent who visited 2 private ophthalmology clinics within the last 10 years were retrospectively reviewed. Glaucoma was diagnosed based on optic nerve findings and presence of visual field defects. Main outcome measures were distribution of glaucoma subtypes, characteristics of different glaucoma subtypes, and comparative results with Japanese American patients without glaucoma.
Results: Of 1732 patients, 112 had glaucoma (6.4%). Of these, 17% had high-tension glaucoma (HTG) and 70% had normal-tension glaucoma (NTG). There were 2 patients with primary angle-closure, 3 with mixed-mechanism, and 10 with secondary glaucoma. The presence of glaucoma was positively correlated with age, refractive error, visual acuity in logarithm of the minimum angle of resolution, and intraocular pressure, while there was a negative correlation between central corneal thickness and glaucoma. Controlling for age, intraocular pressure and visual acuity remained significantly correlated with glaucoma.
Conclusions: In this large Japanese American clinic population, the proportion of patients with glaucoma who had NTG was 4-fold higher than those with HTG. A prospective population-based study may be warranted to further define the spectrum of glaucoma and the reason for the high proportion of NTG in this population.