SMILE LENTICULES FOR CROSSLINKING ON THIN CORNEAS.

Patients with progressive keratoconus often have corneal thicknesses of less than 400 microns. Performing cross-linking in this context is a challenge that must often be met, and for which there is no consensus. 
The aim of our study is to evaluate the initial results of cross linking on thin cornea with the addition of a SMILE lenticule to achieve a corneal thickness greater than 400 microns.

Single-center analytical study at Rouen University Hospital 

Five patients with progressive keratoconus and a corneal thickness less than 400 microns underwent cross-linking by adding a SMILE lenticule of known thickness to the corneal surface, so that the total thickness was greater than 400 microns. The SMILE lenticule was recovered after myopic surgery and stored at the Rouen University Hospital corneal bank. We assessed efficacy by studying pre- and post-operative visual acuity, maximum keratometry and minimum pachymetry on pentacam topography, and the presence of a line of demarcation by performing a post-operative HD corneal OCT. Specular microscopy was performed to ensure the absence of endothelial complications. These elements were evaluated at 1 and 3 months post-op. 

There were no statistically significant differences in visual acuity, maximum keratometry or minimum pachymetry. Endothelial cell density did not appear to be altered, suggesting good safety and tolerance of the technique.

The use of a SMILE lenticule appears to be a useful aid to cross linking in patients with progressive keratoconus and thin cornea. A larger number of patients would be interesting to confirm these results.