To investigate the preoperative clinical factors affecting the refractive outcome after laser-assisted subepithelial keratomileusis (LASEK).

This retrospective study was conducted on 58 patients (116 eyes) who underwent bilateral LASEK using the MEL60. The outcome efficacy and predictability of LASEK was examined by analyzing data including age, gender, preoperative uncorrected visual acuity, preoperative refraction (spherical equivalent and cylindrical diopter), central corneal thickness, tear breakup time, and Schirmer test through multiple logistic regression analysis.

The preoperative factor associated with postoperative uncorrected visual acuity was the amount of preoperative spherical equivalent. Greater preoperative spherical equivalent was associated with decreased efficacy. Predictability was also associated with the amount of preoperative spherical equivalent. Greater preoperative spherical equivalent was associated with decreased predictability. The other preoperative factors including sex, age, preoperative uncorrected visual acuity, amount of preoperative cylinder diopter, intraocular pressure, tear breakup time, Schirmer test and central corneal thickness did not show any association with efficacy or predictability.

The preoperative spherical equivalent was determined as the most important prognosis factor in LASEK, as it is in PRK or LASIK.