CONTRAST SENSITIVITY AND GLARE DISABILITY WITH DIFFRACTIVE AND REFRACTIVE MULTIFOCAL INTRAOCULAR LENSES

Purpose: To compare contrast sensitivity and glare disability provided by diffractive and refractive multifocal intraocular lenses (IOLs). S etting: University Eye Clinic Vienna, Austria. Method: This study eval uated the contrast sensitivity and glare disability in 29 eyes with a diffractive multifocal IOL (3M815LE) and 12 with a three-piece, five-z one refractive multifocal IOL (AMO Array SSM 26 NB). The Brightness Ac uity Tester (Mentor, Inc.) was used with stationary sinusoidal grating s at spatial frequencies of 0.5, 1, 3, 6, 11.4, and 22.8 cycles per de gree (cpd) generated on a television monitor (Nicolet CS 2000). Result s: The contrast sensitivity functions of both multifocal IOL groups we re within the reference range and were identical at 0.5, 1, and 22.8 c pd spatial frequencies. At 3, 6, and 11.4 cpd, the contrast sensitivit y function in the diffractive IOL group was 6, 9, and 10% lower than i n the refractive IOL group, and the difference between groups was stat istically significant at 6 cpd. When glare was present, contrast sensi tivity in the diffractive IOL group was generally in the lower limit o f the reference range and remained below at 3 and 6 cpd. Contrast sens itivity in the refractive IOL group remained below the reference range at 3 cpd. At 0.5 and 1 cpd, there were no differences between the gro ups. At the middle and high spatial frequencies (3, 6, 11.4, 22.8 cpd) , contrast sensitivity in the diffractive group was 8, 16, 11, and 12% lower than in the refractive group. At 6 cpd, the between-group diffe rence was statistically significant. Conclusion: Diffractive multifoca l IOLs provided decreased contrast sensitivity and greater glare disab ility than refractive multifocal IOLs.