Age-related macular degeneration in Onitsha, Nigeria

To determine the incidence, pattern and ocular morbidity associated with age-related macular degeneration (AMD) at the Guinness Eye Center Onitsha Nigeria.

The case files of all new patients aged 50 years and above seen between January 1997 and December 2004 were reviewed. The files of patients with AMD were further studied. Information on age, gender, occupation, duration of symptoms, type of maculopathy, visual acuity, ocular and systemic co-morbidities were abstracted into a standard proforma and analyzed using the chi-square test, student t-test and confidence interval estimation.

Two hundred and fifty-six of 7966 (3.2%) new patients had AMD; M:F = 2:3; 60 -79 year age group constitute 70% of the cases. Non-neovascular AMD occurred in 210 (82%) patients with 182 (71.1%) having early AMD and 28 (10.9%) geographic atrophy. Neovascular AMD occurred in 46 (18%) patients. AMD was bilateral in 221 (86.3%) patients. Most patients presented late. Systemic co-morbidities were hypertension and diabetes; the main ocular co-morbidities were cataract and glaucoma. Thirty-four (13.3%) patients were bilaterally blind and 130 (50.8%) had bilateral visual impairment. Of the blind patients 13(38.3%) had neovascular AMD and 6 (17.7%) had geographic atrophy. This makes AMD the cause of blindness in 7.4% of the patients. An affected eye was more likely to have low vision than an unaffected eye (95%CI: 0.07, 0.21; P<0.05); persons aged 70 years and above were more likely to be blind (χ2 - 7.26, df -1; P<0.05); females were also more likely to be blind than males (t - 2.857, df - 8; P<0.05) and neovascular AMD significantly causes more blindness than the non-neovascular type (95% CI: 0.11, 0.37; P<0.05).

AMD was the main cause of blindness in 7.4% of the patients. Treatment facilities including low vision aids for AMD patients should be provided in eye hospitals in Nigeria. Health education of the public highlighting the risk factors for AMD should be mounted as part of Vision 2020 programme in Nigeria. A community based study is required to fully define the epidemiologic characteristics of AMD in Nigerians.