The outcome of corneal collagen cross-linking in patients with advanced progressive keratoconus: A 2-year follow-up study

Abstract

PURPOSE: The aim of this study was to evaluate the safety and efficacy of collagen cross-linking (CXL) in advanced progressive keratoconus with a maximum keratometry (K max ) value of more than 58 diopters (D). METHODS: This prospective interventional case series involved patients with advanced progressive keratoconus with a K max of more than 58 D. The best-corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), K max , mean keratometry (K mean ) value, corneal astigmatism, and thinnest corneal thickness before surgery and 24 months after CXL were determined for 30 eyes of 27 patients. A Pentacam was used to measure the paraclinical parameters. RESULTS: The mean age of the patients was 24.47 ± 3.33 years. The mean logarithm of the minimum angle of resolution (logMAR) of the uncorrected visual acuity UCVA decreased from 0.73 ± 0.36 D at baseline to 0.48 ± 0.30 D ( P = 0.01), while the mean thinnest point thickness of the cornea decreased from 438.65 ± 40.11 μm to 431.43 ± 61.92 μm ( P = 0.005) after 24 months. The decreases in the mean logMAR of the BCVA, K max and K mean values, and corneal astigmatism were not statistically significant ( P > 0.05) at the 24-month follow-up. Progression was halted in 29 eyes (96.6%); only 1 eye (3.3%) showed an increase in the K max value of more than 2.0 D, which was indicative of treatment failure. In contrast, most other eyes showed a decrease in the K max value although it was not statistically significant. There were no major complications in any of the patients during the study period. CONCLUSION: Standard CXL treatment was safe and stabilized both the visual acuity and tomographic parameters at the 2-year follow-up in eyes with advanced progressive keratoconus.

Efficacy of enzyme‑induced collagen crosslinking on porcine cornea

“…It has been reported that thickness was reduced after UVA/RF CXL ( 14-16 ). The decrease may occur at the end of the CXL operation ( 11 ) and continue for ≥1 year ( 15 , 16 ). Anatomical and microstructural changes in corneal collagen fibrils, such as the compression of collagen fibrils, may change corneal hydration and edema ( 15 ).…”

Accelerated Cross-Linking for the Treatment of Chronic Corneal Ulcers and Evaluation of Healing with Optical Coherence Tomography (OCT)

“…The procedure used in this prospective clinical study is a specific application of corneal cross-linking for the treatment of corneal ulcers in veterinary medicine, called corneal phototherapy or VET-CXL ® protocol. This procedure was validated in the laboratory for treatment of corneal ulcers in veterinary medicine [5] and was based on the use of higher UV-A power density than previously published treatment protocols in veterinary medicine [12].…”

“…The CXL is a photodynamic therapy which consists in the administration of an ophthalmic solution enriched with riboflavin (vitamin B2) followed by irradiation of the cornea with ultraviolet A light (UV-A). The CXL was introduced in the late 1990s for the treatment of keratoconus [4,5] and corneal ectasia and later proposed as a modality for the treatment of corneal ulcers and bullous keratopathy [6]. In the veterinary field, the procedure has been used to treat several disorders, such as corneal abscess [7], refractory keratitis [8], bullous keratitis [9][10], and keratitis with corneal melting [11][12][13][14].…”