CHANGES IN RETINAL NERVE FIBER LAYER THICKNESS AFTER MECHANICAL MICROKERATOME-ASSISTED LASIK.

Abstract

Purpose: To evaluate the changes in retinal nerve ber layer (RNFL) thickness following mechanical microkeratome assisted laser assisted in situ keratomileusis (LASIK) Material and Methods: This hospital based prospective study was carried out on 56 patients with myopia between -1 and -8.5D and myopic astigmatism of upto -2.5D, who underwent LASIK at the LASIK Centre in the Postgraduate Department of Ophthalmology, Government Medical College, Srinagar for a period of one and a half year (from April 2018 to October 2019). Intraocular pressure (IOP) was noted at all pre and postoperative examinations. RNFL thickness was measured using optical coherence tomography(OCT) prior to the surgery and at 1 month and 3 months postoperatively. Results: The mean age of the patients was 26.9± 4.71 years …. The study included 30(53.5%) males and 26(46.4%) females. At the end of 3 months, the mean spherical equivalent of refraction was -0.25 ± 0.469 compared to a preoperative mean of -4.71 ± 2.043. The mean pre-LASIK RNFL thickness was 105.24±5.43μm and the mean RNFL thickness post-LASIK was 103.96±6.25 μm, and 104.76±5.27μm at 1 month and 3 months respectively. The difference in the RNFL thickness before and after LASIK was not statiscally signicant (p value>0.05).The IOP was within the normal range both pre and postoperatively. Conclusion: LASIK performed in young myopic subjects does not signicantly affect the retinal nerve ber layer thickness as determined by optical coherence study.However the long term effects of the procedure on the optic nerve and RNFL are not clear and require further evaluation.