APOC impact assessment studies: baseline ophthalmological findings in Morogoro, Tanzania

The goal of the African Programme for Onchocerciasis Control (APOC) is to eliminate Onchocerciasis as a disease of public Health significance and an important constraint to socio-economic development in the 19 none OCP (Onchocerciasis Control Project) countries covered through Community-Directed Treatment with Ivermectin, CDTI. In 1998, impact assessment studies were carried out in Morogoro, Tanzania during which baseline ophthalmological parameters were established. The hypothesis being tested is that CDTI will prevent or delay progression of onchocercal eye lesions and blindness. A total of 425 subjects aged 10 years or more from 14 villages within Bwakira district ofMorogoro region in Tanzania were examined for Snellen visual acuity, ocular microfilaria, lens opacities, uveitis and posterior segment disease especially chorioretinitis and optic nerve disease. Motion Sensitivity Screening Test (MSST) was carried out as well. Microfilaria was present in the anterior chamber of nearly half (49.2%) of all subjects examined. Prevalence of blindness was extremely high at 15.2%. Onchocercal lesions were responsible for blindness in 41.5% of these, followed by cataracts (27.7%), glaucoma (10.8%) and trachoma (6.2%). The main pathway to onchocercal blindness in this population was anterior uveitis with or without secondary cataracts. There is an urgent need to get CDTI underway and institute other horizontal primary eye care measures, especially cataract backlog reduction, in order to reduce the excessive burden of avoidable blindness in this community.