Prospective Comparison of Simulated Night Driving Performance After Wavefront Guided Treatments, Both PRK and LASIK, for Moderate and High Myopia

Abstract

Purpose:: To prospectively compare visual performance of subjects treated with wavefront guided PRK and LASIK for moderate and high myopia using a night driving simulator. Their performance was contrasted to groups treated with conventional 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 41 subjects before and 6 months after wavefront guided LASIK (n=21) and PRK (n=20) (VISX laser; preop MSE=-4.96D, SD=0.63D). Each eye was tested independently. All subjects were tested in best-corrected spectacle lenses allowing prospective comparison. Treatment groups were chosen to be similar between the PRK and LASIK groups (sphere, cylinder, MSE). A group of subjects who had received conventional LASIK treatments (i.e. spherocylindrical with transition zone ablation profiles; 44 subjects, 88 eyes), were compared to the group with wavefront guided treatments.

Results:: Significant differences between the conventional and wavefront guided night driving performance was observed (MANOVA, p<<0.01); postop to preop performance was increased for the wavefront guided treatments; the group average improvement was 310 msec (95%CI, 225-400 msec). Conventional LASIK treatments averaged a loss of 350 msec (95%CI, 210-490 msec) Change in performance was not significantly determined by type of road hazard (traffic or business sign, or pedestrian) or which eye (right/left or dominant/non-dominant), or for detection or identification (reading) of the road hazard (MANOVA, p≥0.05). Contrast sensitivity (photopic 5% contrast acuity), intensity of treatment (extent of myopia), and residual refractive error (spherical equivalent and higher order aberrations) all correlated with the change in visual performance during simulated night driving (α=0.05).

Conclusions:: Night driving visual performance can be improved significantly after wavefront guided myopic LASIK. Changes in the quality of vision, measured clinically, correlated with night driving visual performance.

Clinical Trial:: www.clinicaltrials.gov FDA IDE G960041/G970121

Keywords: refractive surgery: comparative studies • vision and action • cornea: clinical science