Change in visual acuity status of patients served by a humanitarian vision clinic in Mexico

Background: The purpose of this study was to quantify the outcome from a humanitarian eye care clinic providing refractive correction. Methods: Entering versus exiting binocular visual acuities at distance and near were measured to evaluate the overall change in the prevalence of visual impairment (20/70 to 20/180) and blindness (20/200 or worse) in 882 patients ages 8 to 89 (mean age 49) in San Blas, Mexico. Results: A total of 413 distance spectacle corrections and 670 near corrections were dispensed within the study sample of 813 subjects. Those entering the clinic with distance visual acuity of 20/200 or worse caused by refractive error and/or ocular disease totaled 78 (9.6%), whereas those exiting with this level of acuity totaled 32 (3.9%). Those who entered with distance acuity constituting visual impairment totaled 105 (12.9%), whereas those exiting with distance visual impairment totaled 31 (3.8%). Those entering with near visual acuity of 20/70 or worse totaled 403 (49.6%), whereas only 27 (3.3%) exited the clinic with visual impairment at near. Of 86 patients with cataracts, 74 showed improved visual acuity with refractive correction. Conclusion: Spectacle correction, especially for near, significantly reduced the burden of visual impairment in this patient sample, even in the presence of ocular disease.