Posters

Collagen cross-linking: comparison of results using iso-osmolar and hypo-osmolar 0.1% riboflavin solution for the treatment of progressive keratoconus

Poster Details

First Author: S.Rachapalle Reddi INDIA

Co Author(s):    P. Padmanabhan                    

Abstract Details

Purpose:

To compare the efficacy of 0.1% iso-osmolar riboflavin (Standard CXL) with 0.1% hypoosmolar riboflavin solution (Hypotonic CXL) as photosentizer for collagen crosslinking in the treatment of progressive keratoconus.

Setting:

Department of Cornea & External Disease, Sankara Nethralaya, Medical Research Foundation, Chennai, India.

Methods:

Patients with documented progression of keratoconus were subjected to CXL in one of 2 protocols – those with thinnest pachymetry of greater than 400µ were subjected to standard CXL, while those with thinnest pachy between 350 to 400µ underwent Hypotonic CXL. Intraoperative pachymetry ensured a corneal thickness of at least 400µ before exposure to UVA. The changes, at a minimum followup of 1year in corrected distant visual acuity (CDVA), retinoscopy, topography (Tomey IV) tomography (Pentacam) and endothelial cell count (Konan) were compared between the 2 groups of patients.

Results:

380 eyes of 304 patients with progressive keratoconus underwent CXL-250eyes with Standard CXL, 130 with Hypotonic CXL. Mean followup was 1.38±0.28yrs, Hypotonic CXL caused significantly more flattening then standard CXL (1.48±0.3D and 0.67 ± 0.16D respectively, p less than 0.01), particularly among eyes with a preop average K greater than 53D. The changes in CDVA, spherical equivalent refraction, topographic cylinder, anterior and posterior corneal elevation between the two protocols were not statistically significantly different. Hypotonic CXL resulted in significantly more corneal thinning (40.54±4.75µ) than standard CXL (28.06±2.35 µ). No significant changes were noticed in endothelial cells counts in either group.

Conclusions:

Hypotonic CXL was effective in stabilizing progression of keratoconus in corneas too thin to undergo standard CXL. However, it results in significantly more corneal thinning.

Financial Disclosure:

NONE