Causes of blindness and low vision in Bayelsa State, Nigeria: a clinic based study.

BACKGROUND

No data are yet available on the causes of blindness and low vision in Bayelsa State of Nigeria.

OBJECTIVE

The study is to provide baseline data on the causes of blindness and low vision in Yenagoa, Bayelsa State, Nigeria.

METHODS

A prospective study was conducted among new consecutive patients presenting at the eye clinic of Niger Delta University Teaching Hospital. Patients with visual acuity of less than 6/18 in the better eye after optical correction or with pin hole as necessary were studied. Their visual acuity was determined using a snellen chart followed by anterior and posterior segment examination using a Haagstreit slit lamp biomicroscope and direct or indirect ophthalmoscope respectively (Keeler). Other information obtained from patients included their age, sex and occupation.

MAIN OUTCOME MEASURE

Visual acuity < 3/60 in the better eye and visual acuity < 6/18 in the better eye.

STATISTICAL ANALYSIS

STATISTICAL ANALYSIS was done using a scientific calculator.

RESULTS

Over a period of one year, 230 patients presented with visual impairement consisting of 124 blind cases and 106 cases of low vision. Their ages ranged from 3 to 90 years with a mean of 48 years. There were 118 males and 112 females giving a male:female ratio of 1:1.1. Cataract and glaucoma were the leading causes of blindness and low vision. Cataract was responsible for 63% of blindness and 49.8% of low vision while glaucoma accounted for 22% of blindness and 17.9% of low vision. The other causes of blindness in decreasing order includes maculopathy (4.3%), retinitis pigmentosa (3.4%), optic atrophy, phtisis bulbi, keratopathy (each 2.6%) and age related macular degeneration (0.9%). The other causes of low vision in decreasing order includes refractive error (15%), maculopathy (5.6), optic atrophy (3.8%), retinitis pigmentosa, retinopathy (each 2.8%) and age related macular degeneration (1.9%). Majority of blindness is avoidable (93.5%), and found in the fifth and sixth decades of life.

CONCLUSION

Cataract and glaucoma are the predominant causes of blindness and low vision in the study population and majority of the blindness (93.5%) is avoidable. A more aggressive approach to clear cataract back log and improvement of early diagnosis and treatment of glaucoma are needed to combart blindness in this community.