Retrospective, comparative study.
All eyes of subjects with a preoperative manifest spherical equivalent (MSE) between −4.50 and −6.00 who underwent night driving simulator (NDS) testing from 2 clinical trials were entered into the study. This comprised 38 cLASIK patients (62 eyes; mean −5.46 diopters [D] MSE) and 21 wLASIK patients (36 eyes, mean −5.20 D MSE).
Patients' records were reviewed from 2 LASIK clinical trials that had similar enrollment criteria. One trial treated patients with conventional LASIK using a bladed microkeratome (cLASIK) and the other treated with a wavefront-guided profile using a femtosecond laser (wLASIK). In both trials, patients with moderate myopia were asked to participate in NDS testing.
The detection and identification distances of road hazards were measured with and without a glare source before and 6 months after LASIK. Each eye was tested independently in best-corrected trial frames by a masked operator.
In every category, there was a mean reduction in the preoperative to postoperative NDS performance after cLASIK (mean change, −21.3 to −27.9 ft, −6.5 to −8.5 m; 95 % confidence interval [CI], −12.0 to −41.3 ft, −3.7 to −12.6 m); there was a corresponding mean improvement after wLASIK (mean change +15.0 to +29.1 ft, +4.6 to +8.9 m; 95 % CI, +8.3 to +41.5 ft, +2.5 to +12.6 m). Significant differences between cLASIK and wLASIK NDS performance was observed in every category (P<0.;01, Tukey's honest significant difference for unequal numbers). A clinical relevant loss of NDS performance (>0.5 seconds) was observed in 32 % to 38 % of cLASIK eyes for all tasks, whereas only 0 % to 3 % of eyes had this loss after wLASIK. Between 2 % and 7 % of cLASIK eyes and 11 % and 31 % of eyes had a significant postoperative improvement in NDS performance in every task.
Wavefront-guided LASIK to correct myopia combined with a femtosecond laser flap significantly improved mean night driving visual performance and was significantly better than cLASIK using a mechanical keratome.
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