Posters

Demarcation line depth in transepithelial collagen cross-linking, for progressive keratoconus with thin corneas, using a hydroxy propyl methyl cellulose-based riboflavin formulation and ultraviolet A

Poster Details

First Author: C.Malhotra INDIA

Co Author(s):    B. Ramatchandirane   A. Jain   A. Gupta   J. Ram           

Abstract Details

Purpose:

To evaluate the demarcation line (DL) depth with transepithelial collagen cross-linking (TECXL) performed for progressive keratoconus with thin corneas, using a hydroxyl propyl methyl cellulose (HPMC) containing riboflavin formulation.

Setting:

Cornea Services of the Advanced Eye Centre (AEC), Post Graduate Institute of Medical Education and Research,Chandigarh, India .

Methods:

In this prospective interventional study, 11 eyes with progressive keratoconus and minimal corneal thickness (MCT) less than 400µm underwent TECXL using a 0.25% riboflavin formulation, containing 1.2% HPMC and 0.01% benzalkonium chloride. Primary outcome measure was DL depth on anterior segment optical coherence tomography one month postoperatively; secondary outcome measures was change in endothelial cell density (ECD) 6 months after TECXL. DL depth was measured and compared by 2 independent observers as an average of 5 readings taken at the corneal apex, and 1.5 and 3 mm nasally and temporally.

Results:

Preoperative mean MCT was 393.27 +/- 6.26 µm. Mean DL depth documented by observer 1 and 2 was 294.36 +/- 57.13 µm and 290 ± 46.18 µm respectively (p = 0.47), with an excellent interobserver correlation (paired sample correlation = 0.95). Mean depth measured at each of the 4 peripheral was comparable to that measured at the centre (all p’s >0.05) . Depth of the DL was not correlated to either baseline MCT or maximal keratometry ( Pearsons correlation coefficient -0.078; p= 0.82 and -0.161; p= 0.64 respectively ). ECD at baseline and last follow up was comparable (p=0.63) .

Conclusions:

TECXL using an HPMC based riboflavin formulation was associated with a DL at approximately 75% depth, in keratoconic eyes with MCT less than 400µm. Despite no endothelial damage being detected in the short term, larger studies with a longer follow up are desirable to establish safety in thin corneas.

Financial Disclosure:

None