Corneal Wound Healing after Small Incision Lenticule Extraction (SMILE)

Abstract

Purpose : To evaluate the wound healing response after SMILE procedure in rabbit model.

Methods : SMILE was performed in both eyes of 12 New Zealand White rabbits. The cap diameter and thickness were 7.5 mm and 100 μm, respectively. The refractive spherical correction was set at -6.00 D. These animals were divided into 6 groups and the follow-up examinations were performed 1 hour, 4 hour and 1 day, 3 days, 7 days and 28 days after surgery. Corneas were evaluated using slit lamp and in vivo confocal microscopy. The enucleated eyes were used for light microscopy, terminal deoxyribonucleotidyl transferasemediated dUTP-digoxigenin nick-end labelling (TUNEL) assay and immunofluorescence staining (Fibronectin, Tenascin C, CD11b, alpha-SMA).

Results : The central corneas did not show any noticeable opacity at any time point of follow-up. In the contrast, there were obvious scar tissues at the incision position. Scattering hyper reflective spots were observed through in vivo confocal microscopy at 4 hours postoperatively. Large sums of TUNEL-positive keratocytes were detected near the laser ablation zone at 1 hour after surgery and decreased afterwards. Inflammation cells were found to enter from the incision into the central cornea. The inflammatory reaction was observed from 1 hour after surgery. The deposition of extracellular matrix (ECM; Fibronectin & Tenascin) was detected at 1 day postoperatively. The distribution pattern of ECM between the central cornea and the incision was different. Alpha-SMA-positive fibroblasts were detected at the incision position, but it was not observed at central cornea.

Conclusions : It is necessary to implement anti-inflammation intervention at early stage after surgery. The non-scar wound healing response was resulted in the different reaction patterns between the central cornea and the incision.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.