Posters

Short-term comparison of transepithelial corneal collagen cross-linking (TECXL) and contact lens-assisted corneal collagen cross-linking (CACXL) for progressive keratoconus with thin corneas

Poster Details

First Author: C.Malhotra INDIA

Co Author(s):    R. Balamurugan   A. Jain   A. Gupta   J. Ram           

Abstract Details

Purpose:

To compare at 6 months ,the efficacy and safety of TECXL (using a dextran free 0.25% riboflavin solution containing 1.2% hydroxy propyl methylcellulose(HPMC) and 0.01% benzalkonium chloride ) and CACXL ( using 0.1% riboflavin solution in 1.1%HPMC, with a riboflavin soaked UV filter free soft contact lens placed on the de- epithelialized cornea before exposure to UVA riboflavin) in patients with progressive keratoconus having thin corneas i.e. thinnest corneal pachymetry between 350 to 400�Â�µm.

Setting:

Prospective, comparative, randomized, interventional study carried out at the Cornea Services of the Advanced Eye Centre (AEC), Post Graduate Institute of Medical Education and Research,Chandigarh, India

Methods:

The study included 20 eyes randomised to undergo TECXL (n=11) and CACXL (n=9). Parameters compared included manifest refractive spherical equivalent (MRSE), logMAR corrected distance visual acuity(CDVA), maximum keratometry (Kmax), corneal hysteresis (CH), cornea resistance factor (CRF), endothelial cell density (ECD) and depth of demarcation line (DL) on anterior segment optical coherence tomography (ASOCT). Regression , stabilization and progression in any patient was defined respectively as decrease of K max by �â�‰�¥ -1D, K max value within �Â�± 1 D value and increase of K max by �â�‰�¥ 1D as compared to baseline.

Results:

Preoperatively all parameters were comparable between the two groups (all p�â�€�™s > 0.05). At last follow up ECD remained stable ,CDVA,CH and CRF increased while MRSE and Kmax decreased in both groups ,though only increase of CRF in the TECXL group was significant (p=0.04). Inter group comparison of all parameters at last follow up was also comparable (all p�â�€�™s >0.05) except CRF which was significantly higher in the TECXL group (p=0.04).In TECXL and CACXL groups DL depth was 294.36 �Â�± 57.13�Î�¼m and 308.22 �Â�± 84.19�Î�¼m respectively ( p=0.66) while stabilization/regression was seen in 90.9 % and 88.9% eyes respectively (p>0.05).

Conclusions:

Both TECXL and CACXL performed using a dextran free riboflavin solution, demonstrated equal efficacy and safety for stabilizing progressive keratoconus in patients with thin corneas in the short term. DL depth, considered a surrogate measure of the effectiveness of the cross linking procedure was also comparable amongst the two groups. Though a longer follow up and larger patient database is desirable, both these techniques appear promising in terms of their potential to treat keratoconus patients with corneal thickness less than 400�Î�¼.

Financial Disclosure:

NONE