Lenticule thickness precision in small incision lenticule extraction (SMILE): a target–actual comparison using spectral-domain OCT

Session Details

Session Title: SMILE: Small Intrastromal Lenticule Extraction I

Session Date/Time: Sunday 11/09/2016 | 08:00-10:00

Paper Time: 08:00

Venue: Hall H1

First Author: : N.Luft AUSTRIA

Co Author(s): :    M. Ring   M. Bolz   M. Dirisamer   A. Mursch-Edlmayr   T. Kreutzer   S. Priglinger     

Abstract Details

Purpose:

To compare the planned and achieved corneal stromal thickness reduction in small incision lenticule extraction (SMILE) as well as the secondary changes in stromal thickness during the first 12 postoperative months.

Setting:

Ars Ophthalmica Study Center, Department of Ophthalmology, General Hospital (AKH), Faculty of Medicine, Johannes-Kepler-University, Linz, Austria

Methods:

This prospective observational study included eyes that underwent uneventful myopic SMILE. Anterior segment SD-OCT (RS-3000 Advance; NIDEK Co. Ltd., Gamagori, Japan) was used to assess the central corneal stromal thickness before and multiple times after surgery. Planned maximum (central) lenticule thickness was compared to the measured reduction in central corneal stromal thickness 1 day, 1 week, 6 weeks, 3 months, 6 months as well as 12 months postoperatively.

Results:

Forty eyes of 20 patients were included and mean age was 33±6 years. Mean spherical equivalent of the extracted lenticules was 4.78±1.75 diopters and mean lenticule thickness was 94±24µm. Preliminary results showed that on the first postoperative day the reduction in central stromal thickness change observed with SD-OCT was 23±7µm lower than the programmed lenticule thickness (p<0.01). This discrepancy decreased to 19±8µm, 16±5µm and 18±5µm after 1 week, 6 weeks and 3 months, respectively (all with p<0.01).

Conclusions:

Programmed lenticule thickness was found to be higher than the actual observed decrease in stromal thickness during the first 3 postoperative months after SMILE. These differences might be explained by postoperative corneal edema, stromal remodeling or alignment errors of pre and postoperative measurements. A comprehensive analysis of corneal stromal remodeling during the first 12 postoperative months after SMILE as well as potential effects on refractive and visual outcomes will be presented.

Financial Disclosure:

NONE