Posters

Preoperative and intraoperative ectasia risk factors in laser refractive surgery

Poster Details

First Author: M.Hermina EGYPT

Co Author(s):    M. Roshdy   S. Wahba   A. Elawamry   K. Naguib           

Abstract Details

Purpose:

To study the risk factors associated with ectasia cases after laser refractive surgery

Setting:

Al Watany Eye Hospital, Cairo, Egypt

Methods:

All retrievable data of significance for 84 eyes of 42 patients that underwent refractive surgery (Lasik, PRK, Femtosecond Lasik) and developed ectasia at least in one eye from August 2012 till November 2018 were collected, including slit lamp examination, refraction and Scheimpflug images data. The area under the receiver operating characteristic curve (AUROC) was calculated for 19 different risk factors.

Results:

The preoperative and intraoperative risk factors of highest AUROC (> 0.60) were: Back Elevation (BE), Front Elevation (FE), manifest refractive spherical equivalent (SE), Residual Stromal Bed Thickness (RSB), Maximum Keratometry (Kmax), Uncorrected Distant Visual Acuity (UDVA), Thinnest Corneal Thickness (TCT) and Central Corneal Thickness (CCT) (AUROC= 0.729, 0.69, 0.643, 0.633, 0.625, 0.62, 0.62 and 0.611, respectively). On the other hand, other classic risk factors as age, percentage tissue altered, and Index of height decentration (IHD) have less AUROC (0.561, 0.533, 0.524, respectively). The BE index, with the highest AUROC, sensitivity was 76.19% and specificity was 80% at > 6 micrometer.

Conclusions:

The most sensitive and specific ectasia risk factors were elevation indices from tomographic data. It is recommended to include tomographic data to the ectasia risk score system.

Financial Disclosure:

None