Clinical Analysis Of The Complications Of Excimer Laser In Situ Keratomileusis For Myopia

Objective To analyze the complications of excimer laser in situ keratomileusis(LASIK)for myopia, and to discuss the causes, preventions and treatments of these complications.Methods 470 cases (845 eyes) with myopia and myopic astigmatism undertook LASIK and were followed up at least 6 months. The complications of these cases were retrospectively analyzed, also the preoperative visual acuity and the postoperative visual acuity were statistically analyzed. All these cases(845 eyes) were divided into 3 groups according to the preoperative spherical equivalent: Group A:-0.25D～-6.00D(510 eyes); Group B:-6.25D～-10.00D(265 eyes); Group C:-10.25D～-15.00D(70 eyes). The postoperative visual acuity among the three groups were statistically analyzed.Results Intraoperative complications and their rate were: incomplete corneal flap(0.12%); thin flap(0.24%); free cap (0.47%); epithelial defects(4.26%); subconjunctival hemorrhage (1.54%); interface debris(1.66%). Postoperative complications and their rate were: night glare(6.63%); dry eye syndrome(1 month postoperative: 29.35%; 3 month postoperative: 20.36%; 6 month postoperative: 8.52%); corneal epithelial edema(2.25%); epithelial defects and erosions(0.24%); corneal flap folds (0.71%); corneal flap dislocation(0.12%); epithelial implantation (0.24%); lamellar inflammation(1.18%); diffuse lamellar keratitis(DLK) (0.12%); corticosteroid hypertension(0.36%); undercorrection(2.60%); overcorrection(0.83%); induced astigmatism (0.12%); regression(1.89%); loss of best corrected visual acuity (BCVA) (4.97%); accommodative disorder(0.24%).By now, accommodative disorder had not yet been reported in our country, it was a new and special complication in our study.The mean BCVA preoperative was 1.27±0.20, and the mean visual acuity 6 months postoperative was 1.11±0.24, the difference between the two was significant(p＜0.05). 6 months postoperatively, in Group A, the number of visual acuity not less than the BCVA preoperative was 199 eyes (39.02%), the number of less than 1 to 2 rows was 285 eyes (55.88%), and the number of less than 3 rows or much worse was 26 eyes(5.10%). While in Group B,t he corresponding numbers were 126 eyes(47.55%), 134 eyes (50.57%) and 5 eyes(1.88%). And in Group C, the numbers were 22 eyes(31.43%), 37 eyes(52.86%) and 11 eyes (15.71%). The difference between A and B, B and C, A and C were significant (p＜0.05).Conclusions The results indicate that LASIK is a safe and effective method for myopia, but it still has some complications, which to some degree can affect LASIK's result. Accommodative disorder may be a new postoperative complication. The effect of LASIK for low-moderate myopia is better than that for high and superhigh myopia.