African programme for Onchoceriasis control: ophthalmological findings in Bushenyi, Uganda

The overall prevalence of blindness from Onchoceriasis in Bushenyi is relatively low, most of which is to be found in the elderly. Onchoceriasis is a major health problem in Africa. The Community-Directed treatment with invermectin is a control strategy to address the problem, but baseline data are generally lacking in several countries.

To describe baseline ophthalmological data in order to assess the impact of Community-Directed with Ivermectin (CDTI) in Uganda.

The study site was in Bushenyi, Western Uganda. In a cross-sectional study, 367 persons aged 10 years or older from seven selected villages received eye examination using a standardised protocol and Wu-Jones Motion Sensitivity Testing (MSST). Besides MSST, other information sought included visual acuity, slit lamp examination, testicular opacities and intraocular presence.

Of the 367 subjects, 219(57.2%) were males. Subjects less than 25 years of age were 104(28.3). The prevalence of blindness were 1.9% while 4.1% was visually impaired by acuity criteria alone. A further 9.1% had moderate visual field loss while 2.8% had severe field loss. There was no case of anterior chamber microfilaria but dead microfilariae were seen in two cases. Punctate keratitis was present in 1.8% with sclerosing keratitis was twice as common at 3.8%. Optic atrophy was also relatively common at 12.4%, while chorioretinitis was present in 3.3%.

There was an apparent paucity of acute onchocerciasis-related lesions but a significant presence of irreversible onchocerciasis-related lesions. The most significant problem requiring intervention would appear to be cataract.