Observation of mechanical automated microkeratome LASIK treat poor visual quality after radial keratotomy

Abstract

Objective To evaluate the safety,efficacy,and predictability of mechanical automated microkeratome laser in situ keratomileusis (LASIK) in eyes underwent radial keratotomy (RK).Methods In this retrospective case-series study,38 eyes of 27 patients who had undergone RK were performed automated microkeratome One Use-Plus LASIK,including 20 myopic eyes and 18 hyperopic eyes,among them 22 eyes with irregular astigmatism.The patients were 11-24 years after RK,38-53 years old,The mean spherical equivalent was -9.50-+4.25 D,the number of RK incisions was 8-32,the cornea thickness was 512-557 μm.An Allegretto system was used. Data were analyzed using a paired samples t test and a one-way ANOVA. Results No free flap,incomplete flap and flap or eye ball broken happened during the surgeries.The flap thickness was (102.0±7.7)μm.The stromal bed was smooth,9 eyes with corneal epithelial border defect was found and 7 eyes with cornea bleeding.The percentage of uncorrected visual acuity equal to or better than preoperative best corrected visual acuity (BCVA) at 1 day,1 week,1 month and 6 months after surgery was 63％,82％,88％ and 87％.Postoperative BCVA post surgery of all the 38 eyes were equal to or better than BCVA before surgery.Excursion or undersize of the operation field in 22 eyes which received corneal topography guided individual surgery was corrected in varying degree.The coma,total higher-order aberration were reduced obviously after surgery (t=-3.70,4.10,P＜0.01).The significant difference of contrast sensitivity was found in the frequency of 3.0 c/d and 18.0 c/d (t=-2.45,-3.24,P＜0.01).Conclusion Automated microkeratome One Use-Plus LASIK is an effective and safe method to treat post-RK poor visual outcomes. Key words: Keratomileusis,laser in situ; Radial karatotomy; Corneal flap; Visual quality; Contrast sensitivity