Posters

Specular microscopy changes following corneal cross-linking in thin corneas

Poster Details

First Author: Y.Cai UK

Co Author(s):    D. Gore   H. Ong   M. Leucci   B. Allan           

Abstract Details

Purpose:

Corneal cross-linking (CXL) in corneas thinner than 400 microns is widely considered a contraindication due to the risk of endothelial cell damage from ultraviolet A radiation. Some newer CXL devices are licensed to treat below this threshold. We report specular microscopy outcomes in thin corneas less than 400 microns.

Setting:

Moorfields Eye Hospital, London

Methods:

Patients were identified from a prospective electronic medical record database of all keratoconics aged 16 years of age and older undergoing accelerated CXL (pulsed irradiance 30 mW/cm2; energy 7.2 mJ/cm2). Eyes with a minimum pachymetry on Pentacam tomography of 399 microns or less were included for analysis. Specular microscopy (CellChek, Konan Medical USA Inc., Irvine, CA) was taken at baseline, 6 and 12 months employing automated image analysis. Up to three attempts were made to capture a specular image of sufficient quality for analysis. Both endothelial cell density (ECD) and coefficient of variation (CV) were recorded.

Results:

232 eyes (stage IV, mean [SD] K2 56.2 D [6.6]) met the inclusion criterion. Mean (SD) baseline minimum pachymetry was 383 (28) microns (range 352 – 399). In 160 eyes, specular image acquisition failed. In the remaining 72 eyes, baseline mean (SD) ECD was 2,748/mm2 (491), with a mean (SD) CV of 32 (19). At 12 months, mean (SD) ECD was 2,738/mm2 (639) with a mean (SD) CV of 34 (18), p = 0.62. No eyes clinically decompensated.

Conclusions:

Accelerated CXL appears safe below 400 microns. However, poor specular microscopy acquisition and repeatability in very steep corneas may limit accurate assessment.

Financial Disclosure:

None