Low vision in persons aged 50 and above in the onchocercal endemic communities of Anambra State, Nigeria.

OBJECTIVE: To determine the prevalence and causes of low vision among persons aged 50 and above in the onchocercal endemic rural areas of Anambra State, Nigeria.

MATERIALS AND METHODS: Normal residents of three onchocercal rural villages in 3 local government areas of Anambra State, Nigeria, selected through simple random sampling, were examined using interviewer-administered structured questionnaire. Eye examination included visual acuity test, refraction, tonometry, color vision test and direct ophthalmoscopy. Skin-snips were examined for onchocercal microfilaria.

RESULTS: Four hundred and seventy-two persons aged 50 years and above were examined, out of which 8.6% were bilaterally blind; 11.9% were monocularly blind and 23.7% had visual impairment. Cataract caused blindness in nearly two-third of the cases. Other causes of low vision include age-related macular degeneration, glaucoma, onchocerciasis and refractive errors. Of the 56 subjects blinded by cataract in at least one eye, only 16 (28.6%) had undergone cataract surgery. But none had intra-ocular lens implant. Only 2 of these 16 subjects had aphakic eyeglasses.

CONCLUSIONS: Blindness rate among the population studied is 6 times the rate in similar aged-matched population in developed countries. Most of the bilaterally blind will have vision restored through cataract surgery. Cataract extraction with intra-ocular lens implant is recommended for better visual rehabilitation.