Comparison of Night Driving Performance after Wavefront-Guided and Conventional LASIK for Moderate Myopia
Received 30 May 2008; received in revised form 19 November 2008; accepted 15 December 2008.
Purpose
To compare preoperative and postoperative changes in simulated night driving performance after wavefront-guided (wLASIK) and conventional LASIK (cLASIK) for the treatment of moderate myopia.
Design
Retrospective, comparative study.
Participants
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).
Methods
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.
Main Outcome Measures
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.
Results
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.
Conclusions
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.
Financial Disclosure(s)
Proprietary or commercial disclosures may be found after the references.
The Navy Refractive Surgery Center, Naval Medical Center, San Diego, California
Correspondence: Steve Schallhorn, 11730 Caminito Prenticia, San Diego, CA 92131
Manuscript no. 2008-664.
Financial Disclosure(s): S. Schallhorn is a consultant for Advanced Medical Optics and AcuFocus. No other authors has any proprietary or commercial interest in any materials discussed in this article.
Funded by the Commander Naval Air Forces but had no role in the design or conduct of this research.
ABSTRACT