Assessing the Effects of a "Yellow" Tinted IOL on Scotopic and Photopic Vision

Abstract

Abstract: : Purpose:The recent development of an intraocular lens (AcrySof Natural) that reduces transmission of short–wavelength light has led to speculation that visual performance in patients receiving these implants may be affected. To assess this possibility hue discrimination and dark–adapted sensitivity to a range of wavelengths were measured in healthy young individuals with and without a trial lens made with the same chromophore. Methods:Eighteen subjects, ranging in age from 22–27 years, with corrected visual acuity of >=20/20 were tested monocularly with and without a trial lens made with the AcrySof Natural intra–ocular lens (IOL) chromophore. This lens mimics the SN60AT transmission curve. Hue discrimination was measured with the FM 100–hue test under standard illuminant C conditions. Following pupil dilation and 40 minutes of dark adaptation, rod–mediated thresholds to 440 nm, 500 nm, 650 nm and "white" light stimuli were then measured in 23 locations using a modified Humphrey perimeter. Results:There were no changes in FM 100–hue error scores or axes with the lens. Dark– adapted sensitivities to the 440 nm stimulus were decreased by an average of 0.25 log unit with the lens. However, sensitivities to the 500 nm, 650 nm, and "white" light stimuli were only decreased by an average of 0.1 log unit. Conclusions:This "yellow" tinted lens did not affect hue discrimination even under illuminant C conditions. Dark–adapted sensitivities to 440 nm were slightly decreased but sensitivities to wavelengths >=500 nm and to "white" light were only trivially affected. These results suggest that visual performance should not be significantly impaired.

Keywords: cataract • color vision • aging: visual performance