Posters

Comparison of different corneal collagen cross-linking protocols

Poster Details

First Author: C. Utine Yıldırım TURKEY

Co Author(s):    R. Kucumen   U. Cengiz   B. Sahan Gokce   Z. Ayhan           

Abstract Details

Purpose:

To compare the results of standard versus accelerated collagen cross linking (CXL) with different riboflavin solutions, UV-A fluence levels and timing.

Setting:

Dokuz Eylul University Faculty of Medicine, Department of Ophthalmology and Yeditepe University Eye Center

Methods:

Progressive stage 2-3 keratoconus patients randomly underwent epithelium off CXL with Dresden protocol (3 mW/cm2 UV-A for 30 minutes) using riboflavin %0.1 – dekstran 20% (MedioCrossD®, Avedro, Inc) (Group 1) or accelerated CXL (9 mW/cm2 UV-A for 10 minutes) using riboflavin 0.1% – hydroxypropylmethylcellulose (HPMC) 1.1% solution without dextran (MedioCrossM®, Avedro, Inc) (Group 2). Changes in uncorrected and best spectacle-corrected visual acuities (UCVA and BSCVA, respectively), refractive spherical equivalent (SE), simulated keratometric (SimK) readings by Scheimpflug topography (GalileiTM, Ziemer or Pentacam®, Oculus) and intrastromal demarcation line depths by anterior segment optical coherence tomography (VisanteTM AS-OCT, Zeiss) were analyzed postoperatively.

Results:

Twenty-two eyes of 22 patients (Group 1), 18 eyes of 15 patients (Group 2) had primary CXL. In both groups, preoperative mean age, SE, SimK and thinnest pachymetry were similar (p>0.05 for all). Postoperative changes in UCVA (0.11±0.18 and 0.08±0.22), BSCVA (0.09±0.29 and 0.08±0.22), SE (0.39±1.97 and 0.25±6.62), SimKaverage (-0.75±1.35 and -0.53±2.81) and thinnest pachymetry (-24.39±18.89 and -27.0±30.83) were similar in both groups (p>0.5 for all). Postoperative AS-OCT revealed a stromal demarcation line at a depth of 274.33±84.88µ in Group 1, 274.8±61.42µ in Group 2 (p=0.99). None of the eyes revealed signs of endothelial cell damage and stromal edema postoperatively.

Conclusions:

Collagen cross linking with 30 minutes timing and 3 mW/cm2 UV-A fluence at Dresden protocol with riboflavin-dextran solution or 10 minutes timing and 9 mW/cm2 UV-A fluence with riboflavin-HPMC solution at accelerated protocol seem to have similar clinical outcomes at short term. In order to better assess the efficacy, long term follow-up in terms of disease progression are warranted.

Financial Disclosure:

NONE