Corneal stability of LASIK and SMILE when combined with collagen cross-linking

Session Details

Session Title: LASIK vs SMILE

Session Date/Time: Monday 24/09/2018 | 16:30-18:00

Paper Time: 17:18

Venue: Room A3, Podium 2

First Author: : A.Konstantopoulos UK

Co Author(s): :    Y. Liu   E. Teo   C. Nyein   G. Yam   J. Mehta        

Abstract Details

Purpose:

To investigate whether small incision lenticule extraction (SMILE) is associated with less ectasia than laser assisted in-situ keratomileusis (LASIK) and whether concomitant collagen cross-linking is protective in SMILE Xtra and LASIK Xtra.

Setting:

Singapore Eye Research Institute, Singapore

Methods:

Using an established LASIK rabbit ectasia model, we performed -5 dioptre (D) LASIK on 6 eyes and -5D SMILE on 6 eyes. Using the Avedro LASIK Xtra protocol, 5 eyes had -5D LASIK Xtra and 5 eyes -5D SMILE Xtra. Anterior Segment Optical Coherence Tomography and corneal topography were carried out before surgery and at postoperative weeks 2 and 4. Mean [SD] values of postoperative keratometry (K), maximum posterior elevation (MPE) and minimum corneal thickness (CT) were compared to before surgery and amongst the surgical groups (paired t-test, ANOVA). P-value less than 0.05 was considered statistically significant.

Results:

Mean [SD] K-values decreased significantly following SMILE, SMILE Xtra, LASIK and LASIK Xtra. The MPE increased significantly following LASIK, LASIK Xtra and SMILE; a borderline increase was observed following SMILE Xtra (p=0.05). The MPE was less following SMILE than LASIK, but of borderline statistical significance (week 2: 17.73 [5.77] vs. 22.75 [5.05] μm; p=0.13); post-LASIK Xtra MPE was also less than following LASIK (week 2: 13.39 [3.05] vs. 22.75 [5.05] μm; p<0.001). No difference was detected between SMILE and SMILE Xtra. CT decreased significantly following surgery in all surgical groups; no differences were detected amongst the groups.

Conclusions:

SMILE had less potential than LASIK to induce ectasia. Concomitant CXL had a protective effect; LASIK Xtra and SMILE Xtra showed the smallest increase in posterior corneal surface elevation.

Financial Disclosure:

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