Posters

Evaluation of the effect of cornea apex displacement in myopic small incision lenticule extraction on visual acuity and corneal high order aberrations

Poster Details

First Author: G.Asimellis USA

Co Author(s): A. Lazaridis                    

Abstract Details

Purpose:

To investigate the effect of corneal apex (CA) displacement following Small Incision Lenticule Extraction (SMILE) for myopia and myopic astigmatism on corrected distance visual acuity (CDVA) and corneal higher order aberrations (HOAs)

Setting:

Department of Ophthalmology, Philipps University of Marburg, Germany Kentucky College of Optometry, University of Pikeville, KY, USA

Methods:

Forty eyes of 40 patients, who underwent uncomplicated SMILE, were included. One eye was selected randomly in the cases of bilateral SMILE surgeries (38/40 patients). The postoperative CA displacement was evaluated with an objective, digital, comparative analysis technique using the Java-based software ImageJ (version 1.49) to digitally process Scheimpflug-imaging data derived from the Pentacam HR (Oculus Optikgeräte GmbH, Wetzlar, Germany). Examinations were performed preoperatively, one week, one month, and three months postoperatively. Correlations between CA displacement and CDVA, as well as residual HOAs (calculated for a pupil diameter of 6.0 mm) of the anterior cornea were investigated.

Results:

Preoperative manifest residual spherical equivalent (MRSE) was –5.75±1.65 D and the cylinder was -0.55±0.66 D. The 3-month MRSE was –0.45±0.32 D (p = 0.002) and the cylinder was -0.25±0.15 D (p < 0.005). The CA displacement was 0.30±0.15 mm. The preoperative CDVA was 0.10±0.05 logMAR and the 3-month postoperative CDVA was -0.02±0.05 logMAR (p=0.05). There was a moderate relationship between postoperative CDVA and CA displacement (r=0.55) and a strong relationship between postoperative HOAs and CA displacement (r=0.75).

Conclusions:

The CA displacement after SMILE has a stronger effect on the amount of the induced HOAs rather than on visual acuity.

Financial Disclosure:

None