Posters

Collagen shield-assisted corneal cross-linking in progressive keratoconus with corneal thickness below 400�Â�µm

Poster Details

First Author: H.Suleman UK

Co Author(s):    D. Dacosta   S. Gurney   M. Khan   S. Shah           

Abstract Details

Purpose:

The use of contact lens assisted corneal cross linking (CXL) in sub-400�Â�µm corneas has been published. However, contact lenses consist of materials which differ significantly from human corneal tissue and therefore may have differing uptake and absorption of riboflavin and ultraviolet (uv) light and therefore may transmit a variable amount of uv light to the host cornea compared with using human cornea to make up the deficit. Herein, we describe the use of collagen shields as a more �â�€�˜physiological�â�€�™ method to make up the deficient stroma in the CXL of keratoconic patients with sub-400um corneas.

Setting:

Birmingham & Midland Eye Centre, UK.

Methods:

A pilot study was carried out to determine which collagen shield (24h or 72h Oasis) was most suitable. Patients underwent an accelerated epithelium off CXL protocol (10mW/cm2 for 9 minutes) with the riboflavin soaked collagen shield in-situ. Once the procedure was complete, the collagen shield was discarded and a standard post-CXL treatment regimen instituted. Review was at 1 week and 6 weeks. Stabilisation was considered successful if, at the last visit, topography showed no more than 1D increase in Kmax and the thinnest point was no more than 5um below the preoperative value.

Results:

The pilot study revealed that a 24 hour collagen shield had the best tear film and profile for further use. Fifteen patients underwent the procedure . Pre-operative thinnest point pachymetry ranged from 287-395�Â�µm and Kmax ranged from 50.6-83.2D. Fourteen out of the 15 patients were stable at the last visit. There were no patients with any endothelial compromise or any other safety concerns.

Conclusions:

Collagen shield assisted CXL may be an option for patients with progressive keratoconus and abnormally thin corneas. Collagen shields consist of bovine collagen which may be a more �â�€�˜physiological�â�€�™ option compared with the polymers used in standard contact lenses. Much further work remains to be elucidated in terms of long term stability, treatment of a larger cohort of patients and the amount of uv light absorbed in the host cornea with the use of collagen shields and conventional contact lenses. If proven to be successful, this technique may further increase the number of progressive keratoconic patients benefitting from CXL.

Financial Disclosure:

NONE