Comparative study on incidence of posterior vitreous detachment (PVD) between conventional and femtosecond laser-assisted laser in situ keratomileusis (LASIK)

Abstract

To compare incidence of posterior vitreous detachment (PVD) in patients after microkeratome and femtosecond laser-assisted laser in situ keratomileusis (LASIK) using ultrasound B-scan. Prospective, non-randomised, comparative and interventional hospital based study. This study was performed on 138 eyes of 69 patients, 64 eyes in microkeratome group and 74 eyes in femtosecond laser group for a period of 10 months from December 2017 to October 2018. The mean age of patients in microkeratome group was 23.34 years and in femtosecond laser group was 23.19 years. All patients in both the groups underwent one of the two procedure. Patients were assessed for subjective and objective refraction, presence of PVD, subjective complaints of floaters and axial length changes at each visit. At 1 week and 1 month postoperative period there was no PVD in either of the groups and none of the patients complained about disturbing floaters. At one week postoperative period, 17 eyes (26.5%) in microkeratome group and 22 eyes (29.6%) in femtosecond laser group had residual refraction ranging from -0.25D to -0.75D. The changes in axial length following surgery was 0.08 ± 0.08mm in microkeratome group and 0.1 ± 0.07mm in femtosecond laser group at one month. Our study did not demonstrate any difference between both the procedures with respect to posterior segment complications. Patients in our study are relatively younger compared to other studies and hence, age of the patient undergoing LASIK may affect the incidence of PVD.Both microkeratome assisted LASIK and femtosecond assisted LASIK were comparable with respect to posterior segment complications. The mean age of patients in this study is assumed to have an effect on outcome. Whereas axial length, power of the eye, procedure opted did not significantly have any impact on outcome. A larger population with longer follow up is needed in Indian population to conclude our results.