Free Papers
Comparison of Birefringence properties and collagen structure in LASIK, SMILE and PRK procedures
Free Paper Details
First Author: S.Gupta INDIA
Co Author(s): R. Shetty A. Roy P. Khamar R. N
Abstract Details
Purpose:
Optical Coherence Tomography (PS-OCT) is a functional extension of conventional OCT that provides us additional information in terms of phase retardation and axis orientation. This additional information is known to represent Collagen fibril structure within the cornea. Our purpose is To perform a comparative study of Birefringence properties in laser in situ keratomileusis (LASIK), small incision lenticule extraction (SMILE) and photorefractive keratectomy (PRK).
Setting:
Narayana Nethralaya
Bengaluru
India
Methods:
In this study, Birefringence properties of total 75 eyes, 25 eyes each of LASIK, SMILE and PRK were measured preoperatively and postoperatively at 3 months and 6 months using a custom-built ultrahigh resolution polarization sensitive (PS) – OCT. An imaging size of 11mm was achieved using a conical scan setup. Phase retardation and axis orientation enface maps from posterior cornea were generated to observe deviation in preferential arrangement of collagen fibril structures. All eyes were imaged at least 3 times to ensure repeatability.
Results:
Enface maps of preoperative emmetropic eyes show preferential arrangement of collagen fibril structures. This arrangement of collagen fibrils as seen in phase retardation enface maps deviated largely in LASIK eyes followed by SMILE eyes and deviated the least in PRK eyes. However, the orientation of collagen fibrils appeared to be largely disrupted in LASIK eyes, followed by PRK eyes and the least in SMILE eyes.
Conclusions:
Distinctive differences in birefringence properties and collagen orientation were observed in LASIK, SMILE and PRK eyes. Polarization sensitive information could be used for decision making and monitoring collagen fibril changes resulting in better surgical outcomes
Financial Disclosure:
-
