Abstract
Purpose :
Oncoming headlight glare (HLG) affects night driving in drivers with cataract due to increased intra-ocular light scatter. We have previously shown that bilateral cataracts nearly double response time (RT) in simulated night driving scenarios with dynamic HLG simulation. We tested the hypothesis that following cataract surgery for one eye; RTs improve but are still affected by HLG due to the residual unilateral cataract.
Methods :
We compared pedestrian detection performance within-subjects in the presence (HLGY) and absence (HLGN) of HLG. 6 normal vision (NV) subjects (30 ± 6 years) completed driving experiments under two vision conditions - with simulated unilateral cataract (SUC) (wearing a clip-on with 0.8 Bangerter foil over better eye and clear lens over other eye) or clear lenses over both eyes . Each experiment comprised 6 driving scenarios (3 HLGN, 3 HLGY) that included 30 HLG encounters (24 with and 6 without a pedestrian). Pedestrians walked along the sidewalk or crossed the road from either side. The order of HLG and cataract simulation was counterbalanced. . Patients (PTs) (n=6; 64 ± 13 years) who had undergone cataract surgery for one eye and were scheduled to undergo second-eye surgery performed the same driving experiments before and after second-eye surgery. RTs were analyzed using repeated-measures ANOVA.
Results :
In NVs, we found a significant main effect of HLG (F (1, 5) = 6.46, p = 0.05) and SUC (F (1, 5) = 23.55, p < 0.01), as well as an interaction (F (1, 5) = 7.941, p = 0.04). The RTs with SUC (1.72 ± 0.5 s) were longer than with clear lenses (1.28 ± 0.18 s), and longer under HLGY (1.69 ± 0.52 s) than HLGN (1.31 ± 0.2 s). For PTs, significant main effects of HLG (F (1, 5) = 17.30, p = 0.01), cataract status (F (1, 5) = 24.12, p < 0.01) and interaction (F (1, 5) = 9.78, p = 0.03) were found. RTs were significantly longer under HLGY (2.60 ± 1.07 s) than HLGN (1.47 ± 0.42 s), and longer before (2.2 ± 0.47 s) than after second eye surgery (1.87 ± 1.00 s).
Conclusions :
Oncoming headlight glare affects pedestrian detection when driving at night for persons with unilateral cataract despite successful cataract surgery for the other eye. Clinicians should explain this and instruct patients to exercise caution while driving at night between surgeries.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.