Corneal collagen crosslinking for keratoconus or corneal ectasia without epithelial debridement

Abstract

Purpose Corneal collagen crosslinking (CXL) is a relatively new technique to reduce the progression of keratoconus. The technique can be performed with or without complete debridement of the corneal epithelium. We describe a novel intermediate technique involving mechanical disruption of the epithelium, and evaluate its safety and efficacy. Methods The case notes of 128 eyes with progressive keratoconus or iatrogenic corneal ectasia who had undergone CXL using the epithelial disruption technique were retrospectively reviewed. Thin corneas were treated with hypotonic riboflavin. All others were treated with an isotonic solution. Note was made of preoperative and postoperative parameters, including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, endothelial cell count, and corneal tomography. Occurrence of procedure-related complications was recorded. Statistical analyses were performed using the paired sample t-test and Wilcoxon signedrank test, with a level of Po0.05 being accepted as statistically significant. Results At 12 months, 41.8% of patients treated with isotonic riboflavin had improved UCVA and 29.7% had improved BSCVA. Only 13.4% lost lines of UCVA and 14.9% lost BSCVA. Of the patients treated with hypotonic riboflavin, at 12 months, 75% demonstrated stability of BSCVA and 25% had stable Kmax. In addition, 25% showed improved visual acuity at 12 months, and 58.3% showed regression of their Kmax. Our rate of short-term complications was comparable to studies using complete epithelial removal. Conclusions CXL with epithelial disruption is a safe and effective treatment for keratoconus or iatrogenic corneal ectasia, and may be better tolerated by patients than the epithelium-off technique.

Outcomes of iontophoretic corneal collagen crosslinking in keratoconic eyes with very thin corneas

“…They demonstrate that the corneal epithelial disruption is safe and allows good diffusion of riboflavin in the corneal stroma. [ 11 ]…”

“…Our results on UDVA and CDVA are similar to those of other studies that recorded the stabilization or improvement of these parameters at the end of the follow-up period. [ 11 , 21 , 22 , 30 ]…”

“…[ 2 , 3 , 7 ] Since patients are often diagnosed at advanced stages of disease with pachymetry below 400 μ and the standard CXL is contraindicated, different alternative crosslinking techniques have been proposed: transepithelial CXL with an improved riboflavin with 15% dextran, EDTA, and trometamol, [ 8 ] the use of a hypoosmolar solution of riboflavin, [ 9 ] customized epithelial debridement according to pachymetry, [ 10 ] and disruption of the corneal epithelium with a special instrument in combination with administration of hypotonic riboflavin. [ 11 ]…”

Morphologische Hornhautveränderungen nach Crosslinking bei Keratokonus

“…300 μm abnimmt, wird das Crosslinking bei einer Hornhautdicke von über 400 μm als komplikationsarm und sicher beschrieben [38][39][40][41][42]. Bei dünneren Hornhäuten wird empfohlen, mithilfe von hypotonen Riboflavintropfen die Kornea aufquellen zu lassen, um so auch hier ein sicheres Crosslinking zu ermöglichen [97,[104][105][106][107][108].…”

Fourier Analysis of Keratometric Data in Epithelium Removal versus Epithelial Disruption Corneal Cross-linking

“…The safety, efficacy, and better tolerability of this method have been reported in recent publications. [11][12][13][14] Fourier analysis is a mathematical method that can convert periodic continuous data into unique expressions. Fourier analysis transforms the extracted keratometric data using a Pentacam Scheimpflug camera into spherical R min, spherical eccentricity, maximum decentration, central and peripheral astigmatism, and irregularity components.…”