Abstract

The vitamin A and ocular lesions in 98 rural Nigerians who excreted microfilariae in their skin tissues and had at least one clinical manifestation of onchocerciasis were investigated. The highest prevalence rate of 18 (69.2%) occurred among adult males with leopard skin. The overall mean vitamin status of (20.3 ± 2.6 µg/dl) was comparatively lower (χ² = 41.0; p>0.05) than the control inhabitants (76.2.3 ± 3.8 µg/dl). The mean vitamin status was higher among the infected children (22.7 ± 0.5 µg/dl) than their adult counterparts (17.9 ± 6.1 µg/dl). Also the mean vitamin A status of their infected children (22.7 ± 5.0 µg/dl) was lower (χ² = 31.1; p> 0.05) than their control subjects (73.5 ± 2.1 µg/dl). The vitamin A status of the infected adults (17.9 ±6.1 µg/dl) was lower (χ² = 47.2; p>0.05) than their control counterparts (78.9 ±4.1µg/dl). The mean microfilarial load of the different age groups of the infected volunteers showed negative correlation with the mean vitamin A status (r = -0.93). In all, five different ocular lesions namely cataract, optic atrophy, chroroidoretinitis, iriodocyclitis and sclerosing keratitis were reported.  Visual impairment was absent and the ocular lesions were low among the children as they had only optic atrophy and sclerosing keratitis among the five different lesions encountered.

Key words: Vitamin A, Ocular lesions, Visual impairment, Microfilariae, Onchocerciasis, Rural Nigerians.