Rapid assessment of avoidable blindness in negros island and antique district, Philippines

Objectives: To conduct rapid assessments of avoidable blindness to estimate the magnitude and causes of blindness in people aged >= 50 years in Negros Island and Antique district, Philippines. Methods: Clusters of 50 people aged >= 50 years were sampled with probability proportionate to size. Households within clusters were selected through compact segment sampling. Visual acuity (VA) was measured with a tumbling ``E'' chart. Ophthalmologists examined people with VA<6/18 in either eye. Results: In Negros, 2774 of 3649 enumerated subjects were examined (76.0%) and 3177 of 3842 enumerated subjects in Antique (82.7%). The prevalence of blindness (presenting VA<3/60 in better eye) was 2.6% (95% CI = 2.0 to 3.2%) in Negros and 3.0% (2.4 to 3.6%) in Antique. The leading cause of blindness was untreated cataract, and was refractive error for visual impairment (VA<6/18 to >= 6/60). Most of the cases of blindness (67% in Negros, 82% in Antique) and visual impairment (94% in Negros, 95% in Antique) were avoidable (ie, operated and unoperated cataract, refractive error and corneal scar). In Negros, 23% of eyes had a poor outcome after cataract surgery, and 13% in Antique. Conclusions: The prevalence of blindness in two areas in the Philippines was relatively low. Since most cases were avoidable, further reductions are possible.