Abstract
PURPOSE: To evaluate visual symptoms, ocular higher order aberrations (HOA) and visual performance in the assessment of changes in simulated night driving performance after high myopia LASIK.
METHODS: Detection and identification distances of 2 different road signs and a pedestrian hazard during nighttime driving (rural road at 55 mph, Vision Research Sciences Corp.) with and without glare was measured in 105 subjects before and 6 months fter conventional LASIK (mean pre-op MSE -6.32D). Each eye was tested independently. Visual symptoms were assessed using a survey instrument to determine night glare/halo complaint. Wavefront aberrations were measured using the VISX WaveScan and were analyzed in terms of overall higher order, spherical aberration, coma, and trefoil aberrations; indices based on HOA were developed to assess potential quality of vision. Visual performance was assessed using the photopic 5% contrast acuity test.
RESULTS: Pre-operative level of myopia (amount of correction), subjective night glare/halo complaint (index of multiple questions), HOAs, and 5% contrast acuity all correlated with the change in simulated night driving from pre- to post-LASIK surgery (α=0.05).
CONCLUSIONS: Night driving visual performance can be degraded after conventional myopic LASIK. Changes in the quality of vision, measured objectively and subjectively, correlated with night driving visual performance.