Efficacy of customized corneal crosslinking versus standard corneal crosslinking in patients with progressive keratoconus (C-CROSS study): study protocol for a randomized controlled trial

Magali M S Vandevenne*, Tos T J M Berendschot, Bjorn Winkens, Frank J H M van den Biggelaar, Nienke Visser, Mor M Dickman, Robert P L Wisse, Robert-Jan H J Wijdh, Abhijit Sinha Roy, Rohit Shetty, Rudy M M A Nuijts

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

BACKGROUND: Keratoconus is a degenerative disorder of the cornea leading to a protrusion and thinning with loss of visual acuity. The only treatment to halt the progression is corneal crosslinking (CXL), which uses riboflavin and UV-A light to stiffen the cornea. Recent ultra-structural examinations show that the disease is regional and does not affect the entire cornea. Treating only the affected zone with CXL could be as good as the standard CXL, that treats the entire cornea.

METHODS: We set up a multicentre non-inferiority randomized controlled clinical trial comparing standard CXL (sCXL) and customized CXL (cCXL). Patients between 16 and 45 years old with progressive keratoconus were included. Progression is based on one or more of the following changes within 12 months: 1 dioptre (D) increase in keratometry (Kmax, K1, K2); or 10% decrease of corneal thickness; or 1 D increase in myopia or refractive astigmatism, requiring corneal crosslinking.

DISCUSSION: The goal of this study is to evaluate whether the effectiveness of cCXL is non-inferior to sCXL in terms of flattening of the cornea and halting keratoconus progression. Treating only the affected zone could be beneficial for minimalizing the risk of damaging surrounding tissues and faster wound healing. Recent non-randomized studies suggest that a customized crosslinking protocol based on the tomography of the patient's cornea may stop the progression of keratoconus and result in flattening of the cornea.

TRIAL REGISTRATION: This study was prospectively registered at ClinicalTrials.gov on August 31 st, 2020, the identifier of the study is NCT04532788.

Original languageEnglish
Article number224
Number of pages8
JournalBMC Ophthalmology
Volume23
Issue number1
DOIs
Publication statusPublished - 19 May 2023

Keywords

  • Humans
  • Adolescent
  • Young Adult
  • Adult
  • Middle Aged
  • Keratoconus/drug therapy
  • Photosensitizing Agents/therapeutic use
  • Collagen/therapeutic use
  • Cornea
  • Refraction, Ocular
  • Riboflavin/therapeutic use
  • Photochemotherapy/methods
  • Cross-Linking Reagents/therapeutic use
  • Corneal Topography/methods
  • Ultraviolet Rays
  • Randomized Controlled Trials as Topic
  • Multicenter Studies as Topic

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