Straylight before and after LASEK in myopia: changes in retinal straylight.

PURPOSE

To quantify the changes in retinal straylight that occur after laser-assisted subepithelial keratectomy (LASEK).

METHODS

This prospective study included 86 eyes of 49 patients who were scheduled for LASEK surgery. Patients were divided into groups based on their preoperative contact lens wear habits: rigid lenses (RCL), soft lenses (SCL), spectacles after a period of contact lenses (SaC), and spectacles only (Specs). Retinal straylight was tested before surgery and 6 months after surgery with the compensation comparison method. Straylight was also compared to a normal reference database. The difference with the average straylight increase with age, called base- and age-corrected (BAC) straylight, was also studied.

RESULTS

Before surgery, BAC straylight was found to be strongly elevated, with a value of 0.15 +/- 0.14 log units. After LASEK, this decreased to 0.00 +/- 0.14 log units. The reduction was significant (paired t-test, P << 0.01) and correlated with preoperative BAC straylight levels (r(2) = 0.332; P << 0.01). There was no correlation between the straylight change and the spherical equivalent of the laser refractive correction (r(2) = 0.042; P = 0.059). Preoperative wear of soft contact lenses increased the BAC straylight by approximately 0.06 log units, with respect to the spectacles groups (P < 0.05, unpaired t-test), but after surgery, this difference was no longer found (P > 0.05).

CONCLUSIONS

Higher than normal preoperative BAC straylight was found to normalize after LASEK refractive surgery. Wearing soft contact lenses causes an additional increase in preoperative BAC straylight that is eliminated after LASEK.