Conventional versus accelerated corneal collagen cross‐linking in the treatment of keratoconus. (22nd July 2015)

• Record Type: Journal Article
• Authors: Ng, Alex Lap Ki; Chan, Tommy CY; Cheng, Arthur CK
• Is Part Of: Clinical & experimental ophthalmology. Volume 44:Number 1(2016)
• Page Start: 8
• Page End: 14
• Publication Date: 2015-07-22
• Subjects: accelerated corneal collagen cross‐linking -- corneal collagen cross‐linking -- keratoconus; Ophthalmology -- Periodicals; 617.7
• DOI: 10.1111/ceo.12571
• Languages: English
• ISSNs: 1442-6404

Abstract

Abstract: Background: This study aims to compare the effect of conventional corneal collagen cross‐linking (CXL) with accelerated corneal collagen cross‐linking in treatment of keratoconus. Design: A comparative interventional study was employed. Participants: Participants were consecutive cases of progressive keratoconus receiving either conventional (3 mW/cm 2 irradiance for 30 min) or accelerated CXL (9 mW/cm 2 irradiance for 10 min). Methods: Clinical and topographic parameters were compared between the two groups. Postoperative corneal stromal demarcation line was measured using anterior segment optical coherence tomography. Main Outcome Measures: Clinical and topographic parameters such as corrected distant visual acuity (CDVA), maximum keratometry (Kmax), mean keratometry (Kmean), demarcation line depth were gathered from medical records. Results: There were a total of 26 eyes with an average follow up of 13.9 ± 6.3 months. Fourteen eyes received conventional CXL, and 12 eyes had accelerated CXL. In the conventional CXL group, CDVA improved significantly ( P = 0.021). There was also a significant reduction in Kmax ( P = 0.003) and Kmean ( P = 0.002). In the accelerated CXL group, no significant changes were found in CDVA ( P = 0.395), Kmax ( P = 0.388) and Kmean ( P = 0.952) postoperatively. A significantly greater reduction in Kmax and Kmean were seen in conventional CXL compared to its accelerated counterpart ( P = 0.001 and 0.015, respectively). The demarcation line was deeper in eyes with conventional CXL ( P = 0.013), and the depth correlated significantly with the change in Kmean (r = −0.432, P = 0.045). Conclusion: Conventional and accelerated CXL are effective in stabilizing keratoconus progression after a mean of 12 months. Patients undergoing conventional CXL showed clinical improvement with greater corneal flattening, which correlated with a deeper corneal stromal demarcation line. This current study is the first to report such correlation.