Primary open-angle glaucoma presentation at a tertiary unit in Africa: intraocular pressure levels and visual status

Abstract

Aim: To investigate the presentation of POAG at a tertiary referral hospital in East Africa, including intraocular pressures, visual status and management decisions.

Methods: Retrospective review of first-time presenters with POAG over a 6-month period.

Results: Of the 298 patients identified, mean age 57 years (n = 296, range = 14-88, SD = 14), 213 (72%) male, 122 (41%) had normal vision (using WHO better eye acuity criteria: visual impairment < 6/18, blind < 3/60) at presentation, 87 (30%) had visual impairment and 86 (29%) were blind. The mean presenting IOP was 32 mmHg (SD = 11) and 70% of the patients had a cup:disc ratio of 0.8 or worse in the better eye. Longer disease duration (OR = 1.20, 95% CI 1.04-1.39) and higher mean IOP (OR = 1.06, 95% CI 1.02-1.10) were associated with visual impairment or blindness. Intraocular pressure showed a negative linear correlation with presenting logMAR acuity (R(2) = 0.115, SE = 1.30, p < 0.0005). The mean IOP in eyes that had undergone trabeculectomy (19 mmHg, SD = 8, n = 17) was significantly (p < 0.0005) lower than that in eyes that had not (34 mmHg, SD = 12, n = 274). The referral rate for trabeculectomy was 158/275 (57%). Male sex (OR = 2.17, 95% CI 1.0-4.72), higher mean IOP (OR = 1.09, 95% CI 1.05-1.14) and not being blind (OR = 26.47, 95% CI 9.90-70.78) were associated with surgical referral. Of the 158 patients, 76 (48%) accepted surgery.

Conclusions: A high proportion of patients presenting to our unit with POAG are visually impaired or blind and the higher their presenting IOP the poorer their visual acuity. Previous trabeculectomy was associated with lower IOPs and protection from visual impairment and blindness. Further training of clinic staff towards early surgical referral and investigation of gender barriers is required.