[Cataract-related blindness in Morocco. The Moroccan Group of Epidemiologic Evaluation of Blindness].

The lack of sound and recent epidemiological data on the prevalence and causes of blindness has hampered the development and evaluation of the Moroccan Programme for the Prevention of Blindness. For this reason a population-based survey using a stratified (urban/rural) sampling design for random selection of clusters was carried out in the Kingdom of Morocco from May 15 until June 30, 1992. The procedures used for this survey were those proposed by the WHO Programme for the Prevention of Blindness. A total of 10,198 people were recruited and 8878 examined for a participation rate of 87%. The size and representativity of the sample satisfactorily guaranteed the order of magnitude and accuracy of eye health indicators used by health planners. The crude point prevalence of blindness was 0.8%, that of bilateral poor vision was 2.3%, and that of unilateral poor vision was estimated to be 2.8%. Based on these findings 195,000 people would be blind and 1,300,000 would be at risk of becoming so, for a total of approximately 1,500,000 people with serious visual impairment. Age-related cataract was the most important cause of blindness (45.5%) and bilateral poor vision (43.1%). The prevalence of cataract-related visual impairment--operable or inoperable--was estimated to be 2.1% of the survey sample. Applying a realistic algorithm to the survey data, it was estimated that the backlog for cataract surgery in Morocco in 1992 was in the order of 502,000 eyes in approximately 287,000 people. The percentage of patients who had undergone cataract surgery in hospital was 0.8%. Posterior lens dislocation according to the traditional "couching" method was noted in 0.1% of people studied. It was estimated that 25% of the demand for cataract surgery was covered by available facilities and that 40% of people with aphakia could not obtain eye care.