Abstract
Purpose :
To measure visual acuity in lighting conditions simulating real-life with glare or low contrast in patients with diabetes prior to retinopathy. This information may help physicians counsel diabetic patients on the importance of optimal lighting even before a diagnosis of diabetic retinopathy is made.
Methods :
Observational case-control study of consecutive adult patients with diabetes but without evidence of diabetic retinopathy on funduscopic exam or multimodal imaging compared to controls without diabetes. All patients had best corrected visual acuity (BCVA) testing using the Early Treatment for Diabetic Retinopathy Study (ETDRS) chart and Central Visual Analyzer (CVA). The CVA tests central vision under a variety of surroundings that resemble the varying contrast and luminance of real-life settings. The modules include high contrast situations (M1), reading in a dimly-lit environment (M2), driving at dusk (M3), reading high contrast optotypes with glare (G1), being outside with direct overhead sunlight (G2), and being outside with off-axis sunlight (G3).
Results :
Sixty eyes from 32 patients (40.6% female) of mean age 56 years (range 51-61) were included in the study group and 79 eyes from 46 patients (37.0% female) of average age 59 years (range 54-63) were included in the control group. The study group had a mean logMAR BCVA (95% CI) of 0.14 (0.00 to 0.23), 0.40 (0.31 to 0.50), 0.55 (0.47 to 0.63), 0.32 (0.21-0.43), 0.49 (0.42 to 0.56), and 0.60 (0.53 to 0.67) for modules M1, M2, M3, G1, G2, and G3, respectively. The control group had a logMAR BCVA of 0.01 (-0.04 to 0.06), 0.20 (0.14 to 0.38), 0.33 (0.28-0.38), 0.04 (-0.01 to 0.09), 0.33 (0.27 to 0.38), and 0.40 (0.35 to 0.46) for modules M1, M2, M3, G1, G2, and G3, respectively. There was no significant difference in ETDRS BCVA between groups (p=0.49), but diabetics had a significantly decreased BCVA in all six CVA modules with p values ranging between <0.001 and 0.047.
Conclusions :
Diabetic patients may have decreased visual acuity under conditions simulating real-life situations with suboptimal contrast and glare that precedes the onset of clinical diabetic retinopathy.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.