Dr.Pooja Khamar

Dr. ROHIT SHETTY

Abstract

PURPOSE: To study birefringence in Laser in Situ Keratomileusis(LASIK),Small incision Lenticule Extraction(SMILE) and Photo Refractive Keratectomy(PRK)using Polarisation Sensitive(PS) OCT.

METHODS: Birefringence of 25 eyes each of LASIK,SMILE,PRK were measured pre and postoperatively at 3,6 months using PS– OCT. Image size of 11mm was achieved using a conical scan setup. Phase retardation, axis orientation enface maps were generated to observe deviation in arrangement of collagen fibrils. All eyes were imaged 3 times to ensure repeatability. RESULT: Enface maps of pre-op emmetropes show preferential arrangement of collagen fibrils. This deviated in LASIK followed by SMILE, least in PRK. However, orientation of collagen fibrils were disrupted in LASIK followed by PRK, least in SMILE.CONCLUSION: Distinct differences in optical properties were seen in LASIK,SMILE and PRK. This tool can be used in decision making and monitoring collagen fibril changes in different disease pathologies.

Full Text