Abstract
Abstract: :
Purpose: To determine the effectiveness of individual vision screening tests in the detection of amblyopia and the long term visual outcome of those identified with amblyopia following ophthalmologic intervention. Methods: A prospective study. Vision screening was performed on consecutive patients, born in 1989 or 1990, between January 1995 and September 1995. Vision screening consisted of a visual acuity, binocularity, gross observation and cover testing. All results were forwarded to the local pediatric ophthalmologist. Long term follow up was performed on all treated patients after they had reached visual maturity, i.e. seven years after the initial screening. Results: 2450 children were screened. 172 failed the screening examination. Of those that failed the vision screening, 66.7% were false positives and 33.3% were true positives. The sensitivity and specificity of the screening tests were assessed. Visual acuity and binocularity testing combined had the highest sensitivity of 88.0 and a specificity of 75.5. Binocularity testing had the highest specificity of 89.8 but a low specificity of 16.0. Visual acuity alone had a high sensitivity and specificity of 84.0 and 81.6, respectively. Long term follow up results revealed that 94.4% of children benefited from ophthalmologic intervention following detection of amblyopia. Conclusions: Visual acuity is the most effective screening test. When used alone, gross observation, random dot "E" and cover testing are not effective in vision screening. Visual acuity when used with the Random Dot "E" was more effective than visual acuity alone. Long term visual outcomes revealed that intervention following detection was beneficial.
Keywords: amblyopia • strabismus: diagnosis and detection