The anterior chamber angle width in adults in a tertiary eye hospital in Nigeria

Objective: The objective was to determine the anterior chamber angle width in adult Nigerian patients seen at the Guinness Eye Center Onitsha Nigeria. Materials and Methods: Consecutive new adult patients (aged ≥21 years) seen between March and July 2006 were the subjects of this study. Exclusion criteria included refusal to consent to the test, previous intraocular surgery that could distort the angle integrity and anterior segment pathology precluding the visualization of the angle. Each patient had visual acuity assessment, visual field analysis, ophthalmoscopy, intraocular pressure measurement, refraction, and gonioscopy. The angle grading was by the Shaffer method. Results: Of the 328 patients (648 eyes), aged 21–85 years (median age 59 years), 195 (59.5%) were females and patients older than 50 years constituted 64.9%. Gonioscopy showed that 245 eyes (37.8%) had wide open angles (grades III and IV); 227 (35.0%) had grade II angles; 176 (27.2%) had narrow angles (grade I or slit), 9 of which were deemed occludable. Of the 80 patients with chronic simple glaucoma, 20 (25%) had at least grade III angle; 34 (42.5%) had grade II angle; and 26 (32.5%) had grade I angle. Peripheral anterior synechiae were observed in three eyes. Compared with nonglaucomatous eyes, the angles of the glaucomatous eyes were significantly narrower (P <0.01). Similarly patients older than 50 years were more likely to have narrower angles (P < 0.001). However there was no significant difference between the angle width of male compared to female patients (P >0.05). Conclusions: A little more than a third of adult patients seen in our hospital have wide open angles; a third of the glaucoma patients usually taken as open angle cases actually have very narrow angles some of which are occludable. A population-based study is therefore recommended to clearly define the epidemiologic characteristics of glaucoma including the anterior chamber width in different parts of Nigeria.