CONTRAST SENSITIVITY AND OTHER VISION TESTS IN THE OPTIC NEURITIS TREATMENT TRIAL

PURPOSE: To determine the intercorrelation, prevalence of abnormality, and incremental detection value of vision tests in optic neuritis. ME THODS: We calculated the linear correlation of paired vision tests and prevalence of abnormal test values from baseline and six-month measur ements of Snellen visual acuity, Pelli-Robson contrast sensitivity, Hu mphrey Field Analyzer mean deviation, and Farnsworth-Munsell 100-hue c olor vision in 438 patients entered in the Optic Neuritis Treatment Tr ial from 1988 to 1991. The incremental detection value of nonvisual ac uity tests was defined as their frequency of abnormality when visual a cuity was 20/20 or better. RESULTS: All four vision-test results were highly intercorrelated at baseline and at six months, At baseline, con trast: sensitivity had the highest prevalence of abnormality, but all vision rests were so often abnormal that differences were not clinical ly relevant, At six months, when visual recovery had occurred, contras t sensitivity was most often abnormal (2.2 x visual acuity; 1.8 x mean deviation; 1.5 x Farnsworth-Munsell 100-hue color vision test); when contrast sensitivity, mean deviation, or Farnsworth-Munsell 100-hue co lor vision was normal, visual acuity was 20/25 or better in 98% of pat ients. CONCLUSIONS: The high intercorrelation of four vision tests sug gests that optic neuritis affects a broad range of visual functions, A mong nonvisual acuity tests, Pelli-Robson contrast sensitivity proved to be a particularly practical and sensitive indicator of visual dysfu nction in optic neuritis.