LASIK following Small Incision Lenticule Extraction (SMILE) Lenticule Re-Implantation: A Feasibility Study of a Novel Method for Treatment of Presbyopia

Chris H L Lim,Jodhbir S Mehta,Andri K Riau,Donald T Tan,Nyein C Lwin,Shyam S Chaurasia,Sanjoy Bhattacharya

doi:10.1371/journal.pone.0083046

Abstract

Presbyopia remains a major visual impairment for patients, who have previously undergone laser refractive correction and enjoyed unaided distance vision prior to the onset of presbyopia. Corneal stromal volume restoration through small incision lenticule extraction (SMILE) lenticule re-implantation presents an opportunity for restoring the patients’ non-dominant eye to previous low myopia to achieve a monovision. In this study, we investigated the feasibility of performing LASIK after lenticule re-implantation as a method to create presbyopic monovision. A -6.00D SMILE correction was performed in 9 rabbit eyes. The lenticules were cryopreserved for 14 days and re-implanted. Five weeks later, 3 of these eyes underwent LASIK for -5.00D correction (RL group); 3 underwent LASIK flap creation, which was not lifted (RN); and no further procedures were performed on the remaining 3 eyes. These groups were compared with 3 eyes that underwent standard LASIK for a -5.00D correction (LO); 3 that underwent creation of non-lifted flap (LN); and 3 non-operated eyes. Rabbits were euthanized 1 day post-surgery. Tissue responses were analyzed by immunohistochemistry, slit lamp and in vivo confocal microscopy (IVCM). Intrastromal irregularities and elevated reflectivity levels of the excimer-ablated plane were observed on slit lamp and IVCM, respectively in the RL group. The results were comparable (P = 0.310) to IVCM findings in the LO group. RL and LO groups showed similar fibronectin expression levels, number of CD11b-positive cells (P = 0.304) and apoptotic cells (P = 0.198). There was no difference between the RN and LN groups in reflectivity levels (P = 0.627), fibronectin expression levels, CD11b-positive cells (P = 0.135) and apoptotic cells (P = 0.128). LASIK can be performed following lenticule re-implantation to create presbyopic monovision. The tissue responses elicited after performing LASIK on corneas that have undergone SMILE and subsequent lenticule re-implantation are similar to primary procedure.

Highlights

Laser in-situ keratomileusis (LASIK) is one of the most widely performed elective surgical procedure worldwide [1,2]
We demonstrate the feasibility of performing LASIK following reversal of myopic refractive lenticule extraction (ReLEx) through refractive lenticule re-implantation, as a novel method of inducing monovision in a rabbit model of small incision lenticule extraction (SMILE)
The nine eyes were further divided into three different groups: three eyes had a corneal flap created, which was not lifted; while another three eyes underwent LASIK for -5.00D spherical correction (RL)

Summary

Introduction

Laser in-situ keratomileusis (LASIK) is one of the most widely performed elective surgical procedure worldwide [1,2]. Its popularity stems from the short procedure time, excellent visual outcomes, pain-free and rapid post-operative visual recovery, as well as established safety profile [3,4] This procedure first involves the creation of a corneal flap with either a mechanical microkeratome, or more recently, a femtosecond laser (FSL) [5,6,7,8]. FSLs emit ultra-short light pulses at high frequencies, permitting photodisruption of corneal tissue at lower energy levels [12,13] This is accomplished by initiating rapid gas expansion, which leads to cavitation bubbles formation, thereby creating an intrastromal incision plane with minimal heat development [13]. The photodisruption process, results in minimal collateral damage to adjacent tissues compared to the traditionally high-energy excimer lasers utilized in LASIK [14]

Methods

Results

Conclusion