Rapid assessment of visual impairment due to cataract and cataract surgical services in urban Argentina.

Aim: To present results of a rapid assessment on visual impairment due to cataract and on cataract surgical services in the Northwestern districts of Buenos Aires, Argentina. These results will enable health managers to plan effective interventions in this area in line with VISION 2020.
Methods: One hundred fifteen clusters of 40 persons of 50 years and older in each cluster (4600 eligible persons) were selected by systematic sampling from the Northwestern districts of Buenos Aires, Argentina. This area consists of 10 districts with a total population of 2,716,573 (2001 census), from whom 4302 persons were examined (coverage 93.5%). The visual acuity was measured with a tumbling E-chart and the lens status with distant direct ophthalmoscopy.
Results: Cataract is the major cause of bilateral blindness (54.2%). The age and sex adjusted prevalence of bilateral cataract blindness (presenting VA < 20/400) in people of 50 years and older was 0.5% (95% CI: 0.4-0.8%), an estimated number of 2,985 persons. The cataract surgical coverage at this level was 70% for males and 78% for females. The prevalence of bilateral cataract and VA < 20/200 in persons of 50 years and older was 0.8% (95% CI: 0.6-1.1), an estimated 4,705 persons. In this last group, the surgical coverage was 66% (persons) and 57% (eyes). Of all operated eyes, 10% could not see 20/200. 'Cannot afford' (32%), 'unaware of cataract' (21%) and 'contraindication for surgery' (18%) were mentioned most as reason why surgery had not been done.
Conclusion: The cataract problem is getting under control in this area. Coverage indicators are fairly high, and the outcome data better than in other studies. The cataract surgical rate could be raised further by awareness campaigns and by making cataract surgery more affordable.