Posters

Post-laser in situ keratomileusis ectasia

Poster Details

First Author: M.Fakhry Khattab EGYPT

Co Author(s):    S. Eissa   K. Abdel Aziz   T. ElNaggar   O. Said   A. Abdelatiff   M. Anis     

Abstract Details

Purpose:

Identify risk factors of corneal ectasia following  in situ keratomileusis (LASIK)

Setting:

A multicenter study; 8 centers across Egypt

Methods:

Retrospective cohort study involving 20 eyes with corneal ectasia occurrence between 2012 and 2017 after LASIK.  All eyes were reviewed preoperatively and on ectasia diagnosis for Best Corrected Distant Visual acuity (BCDVA), manifest refraction, and Pentacam parameters including keratometric measurements, sagittal map patterns, corneal front and back surface elevations, point of thinnest corneal pachymetry, Belin/Ambrosio Deviation Display (BAD_D), and Ambrósio relational thickness maximum (ART max). Interval between surgery and ectasia diagnosis was reported for all eyes.

Results:

Preoperative means for sphere and cylinder were -5.2 Diopter(D), and -2.5 D respectively while after ectasia were -3.8 and -2.5 D respectively.  Preoperative sagittal map patterns: 7 eyes Asymmetric Bowtie, 7 Symmetric Bowtie, 2 Crab claw, and 4 normal. For ectasia: 10 eyes central cone, and 10 inferior steepening Treatment included corneal collagen cross linking (CXL) 15 eyes, CXL and intracorneal rings 1 eyes, and Deep anterior lamellar keratoplasty 4 eyes.

Conclusions:

Sagittal map patterns, corneal thickness, BAD_D and ART max are important factors for ectasia prevention.Further analysis of percentage of tissue altered is needed by measuring stromal thickness before and after flap creation and following Excimer laser ablation.

Financial Disclosure:

None