Abstract
Purpose :
Traditional color vision tests do not consistently quantify the type and severity of acquired color vision deficiency or may be too complex for daily use. We hypothesize that cone contrast test (CCT), which overcomes these challenges, will show a difference in color contrast sensitivity before and after cataract surgery, and that this difference is correlated with changes in visual acuity (VA).
Methods :
In this cohort study, 18 cataract patients in their 5th-8th decade of life scheduled for cataract surgery were enrolled (23 eyes). VA, intraocular pressure, and color vision were assessed before and after surgery. Color vision testing was performed via CCT using BCVA under photopic conditions. Average (avg) difference and SD between pre-op and post-op values for all 3 cones were calculated. A t-test comparing CCT values between groups with the best and worst VA changes and linear regression comparing the relationship between changes in VA and CCT were performed. VA was measured using Snellen VA.
Results :
Avg pre-op CCT values were L-cone 52.35 (SD=40.30), M-cone 52.13 (SD=42.51), S-cone 49.52 (SD=36.19). Avg post-op CCT values were L-cone 82.30 (SD=23.52), M-cone 79.17 (26.73), S-cone 88.35 (SD=31.58). Mean differences were L-cone 29.96 (p=0.002), M-cone 27.04 (p=0.001), S-cone 38.83 (p<0.001).
Avg CCT values in the group with the greatest positive change in VA were: S-cone (avg=49.00, SD=28.69), M-cone (avg=55.67, SD=22.30), L-cone (avg=41.33, SD=30.14). Avg CCT values in the group with the least positive change in VA were: S-cone (avg=41.50, SD=29.58), M-cone (avg=35.75, SD=30.67), L-cone (avg=45.75, SD=26.70). Mean difference before and after surgery for the S-cone, M-cone, and L-cone were -7.70 (p=0.751), -19.92 (p=0.389), 4.42 (p=0.845) respectively.
Linear regression showed: L-cone [R2=0.012, B=0.005, 95% CI (-0.017, 0.027), p=0.624], M-cone [R2=0.074, B=0.015, 95% CI (-0.009, 0.040), p=0.211], S-cone [R2=0.036, B=0.010, 95% CI (-0.013, 0.033), p=0.386].
Conclusions :
CCT scores significantly increased after cataract extraction for all three types of cones. The greatest difference was seen for the S-cone, indicating that blue/yellow vision is most affected by cataracts. The average difference in CCT values for all 3 cones between groups with the best and worst VA changes was insignificant. No correlation was found between VA improvement and improvement in CCT values.Changes in CCT values were independent of VA changes.
This is a 2020 ARVO Annual Meeting abstract.