A study of retinitis pigmentosa in the City of Birmingham. I Prevalence.

Using multiple sources, an attempt was made to ascertain all symptomatic cases of retinitis pigmentosa living in the City of Birmingham in June 1978. These methods revealed a prevalence for all ages of 1 in 4869 and a prevalence in the age group 45 to 64 years of 1 in 3195. There was a higher prevalence than expected among young Muslims with consanguineous parents. However, the most accurate prevalence of uncomplicated retinitis pigmentosa among adults was considered to be that found in an outpatient clinic serving adult diabetics, namely, six patients in a clinic population of 8000 to 10 000.