Prospective Comparison of Simulated Night Driving Performance After LASIK Treatment for High Myopia Using Four Different Excimer Laser Systems

Abstract

Abstract: : Purpose: To prospectively compare four excimer laser systems for the treatment of high myopia with LASIK using a night driving simulator to track visual performance. 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 75 subjects before and 6 months after conventional LASIK (4 different lasers; preop MSE –5.712D). Each eye was tested independently. 21subjects/42 eyes were treated with the Alcon Ladarvision 4000, 18/36 with a Bausch & Lomb Technolas 217, 18/36 with a Nidek EC–5000, and, 18/36 with a VISX laser system. Laser group treatments (sphere, cylinder, MSE) were similar (ANOVA, p≥0.7). A fifth group (28 /56 eyes) of higher myopia patients treated with the VISX laser (mean MSE=–7.92D) were prospectively measured, as well. Results: Significant differences between the four lasers in night driving performance was observed (MANOVA, p<<0.001); postop to preop performance was not changed for the VISX, slightly reduced for Alcon, reduced for B&L, and even more reduced in the Nidek group (ANOVA, α=0.05). In the Nidek cohort, average reduction in performance ranged from –29.5ft (0.37sec; 95%CI=–19.3 to –39.7ft) to –40.7ft (0.50sec; 95%CI= –25.0 to –56.6ft) for detection without glare to identification with glare, respectively. 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) was used (MANOVA, p≥0.13). Contrast sensitivity (photopic 5% contrast acuity), intensity of treatment (extent of myopia), and subjective night glare/halo complaint (index of multiple questions) all correlated with the change in visual performance during simulated night driving. Conclusions: Night driving visual performance can be degraded after conventional myopic LASIK and more frequently with certain laser systems. Changes in the quality of vision, measured clinically and assessed subjectively, correlated with night driving visual performance.

Keywords: refractive surgery • refractive surgery: comparative studies • myopia