Glaucoma describes a group of eye diseases characterized by progressive damage to the optic nerve, leading to impaired vision and blindness if untreated. POAG, the most common type in the world and SSA, has a major heritable component in all populations including those of African descent. Vision loss from glaucoma is permanent but can be prevented if it is diagnosed and treated in time. Individuals with glaucoma are often asymptomatic until late in the disease process, when vision loss is advanced in one or both eyes. In developing countries, like those in SSA, over 90% of persons with glaucoma do not know they have it. The prevalence and severity of glaucoma is very high in SSA, approximately 40% are blind in one or both eyes when first seen. For these reasons, glaucoma presents a major public health burden with broad social and economic consequences, especially in SSA. Despite this huge health and socioeconomic burden, public awareness is low and methods to identify glaucoma before it has caused severe vision loss?such as vision screening for the general population?have been ineffective. However, since POAG is highly inherited, targeting high-risk families that have members that were blinded by the disease at an early age offers a potentially powerful way to diagnose glaucoma in their family members before they too are blinded. In fact, reports where selective, targeted screening of high-risk families have been conducted in SSA suggest that this may be an effective approach. We screened high-risk families in Nigeria who had early-onset severe POAG and found that 45% of the first-degree relatives either had POAG or were glaucoma suspects. In this proposal we will evaluate the efficacy of this approach to identify glaucoma at an early, more readily treated stage. We will provide information to family members to increase glaucoma awareness, refer those diagnosed with POAG or suspect status for evaluation and treatment. In addition, we will enroll these families for genetic linkage studies (Project 1) to help determine the underlying genetic cause.
