Abstract
Purpose: :
To compare the visual acuity (VA) under different contrast levels (100%, 25%, 10% and 5%) in patients receiving a UV and blue-light filtering IOL (Alcon AcrySof Natural SN60AT) in one eye and a UV-only filtering IOL (Alcon AcrySof SA60AT) in the other.
Methods: :
Patients who had implantation of a SN60AT IOL in one eye (SN group) and a SA60AT IOL in the other eye (SA group) were identified. Inclusion criteria included age between 50 and 80 years, best corrected visual acuity (BCVA) of 20/25 or better, agreeing to participate in the study, which was approved by the Medical Center IRB, and signing the informed consent. Exclusion criteria were diabetes, posterior capsular opacity, glaucoma, macular degeneration and astigmatism greater than 1.5 D. A total of thirteen patients completed the study. Visual acuity in four different constrast levels was obtained with a multi-functional visual acuity tester (MFVA100) under mesopic condition, and the pupil size was measured with a Colvard infrared pupillometer (Oasis) in the same luminance condition.
Results: :
The mean BCVA was -0.016 ± 0.037 logMAR in SN group and -0.015 ± 0.086 logMAR in SA group under 100% contrast level. The mean difference of BCVA in SN group from that in SA group under 25%, 10% and 5% constrast levels were -0.136 ± 0.165, -0.221 ± 0.312 and -0.223 ± 0.263 logMAR, respectively. The mean pupil diameter in millimeters was 4.4 ± 1.1 (SN group) and 4.4 ± 1.2 (SA group).
Conclusions: :
The two groups had similar BCVA under 100% contrast level. However, the SN60AT IOLs produced better BCVA than the SA60AT IOLs under lower contrast levels (25%, 10%, and 5%). The yellow filter IOLs may provid patients with better visual function for conducting daily life activites, such as working and driving under low contrast conditions.
Keywords: intraocular lens • visual acuity • contrast sensitivity