Accelerated corneal crosslinking in children with keratoconus: 5-year results and comparison of 2 protocols

Abstract

Purpose: To evaluate long-term clinical results of 2 different accelerated corneal crosslinking (CXL) protocols in pediatric patients with keratoconus. Setting: Beyoğlu Eye Training and Research Hospital, Istanbul, Turkey. Design: Retrospective case-control study. Methods: Patients who were younger than 18 years were included in the study. Group 1 received 4 minutes of illumination at 30 mW/cm2, and Group 2 received 5 minutes of illumination at 18 mW/cm2. Uncorrected and corrected distance visual acuities, manifest refraction, corneal topographic parameters, and corneal higher-order aberrations (HOAs) were evaluated at baseline and during 1-, 3-, and 5-year follow-up visits. Results: A total of 143 eyes from 86 patients were included in the study. There were 30 eyes in Group 1 and 113 eyes in Group 2. The mean follow-up time was 4.15 ± 0.99 years. Mean keratometry (K) and/or maximum K progressed ≥1.00 diopter (D) in 7 eyes (23.3%) in Group 1 and 19 eyes (16.8%) in Group 2 (P = .411). Mean K and/or maximum K decreased ≥2.00 D in 2 eyes (6.7%) in Group 1 and 24 eyes (21.2%) in Group 2 (P = .06). In Group 1, there were no statistically significant differences in topographic parameters during follow-up. In Group 2, there was a statistically significant reduction in total HOA and coma during the 5-year visit when compared with the preoperative visit (P = .005 and P = .045, respectively). Conclusions: Accelerated CXL is beneficial in terms of halting the progression of keratoconus in pediatric patients throughout 5 years of follow-up examinations. An increased irradiance with a reduced application time reduces the topographic effects of CXL.

Epithelial Remodelling After Epithelium-off Continuous Accelerated Corneal Collagen Cross-linking in Progressive Keratoconus

“…Successful treatments of KC should address two distinct factors: the optical ine ciency of corneal irregularity and the disease progression of corneal bulging; these may be required for corneal transplantation [10]. Recently, CXL performed with the Avedro KXL system has been established as an effective therapeutic technique for halting the progression of KC [2,[4][5][6]. To our knowledge, this study is the rst to retrospectively evaluate the regional corneal epithelial and stromal remodelling after epi-off continuous accelerated CXL with AS-OCT.…”

“…In current study, UDVA signi cantly improved at 3 months after treatment, and UDVA improved or remained stable in 17 (51.5%) eyes at 12 months after treatment with a mean improvement of 0.16 logMAR. A reduction in the keratometric values may be used to assess the e cacy of the procedure [6]. Ağca et al [6] reported the mean reductions in mean K (K mean ) and maximum K (K max ) were less than 0.25 D, and K max decreased ≥ 1.00 D in 38 (33.6%) eyes during the 5 years follow-up.…”

“…A reduction in the keratometric values may be used to assess the e cacy of the procedure [6]. Ağca et al [6] reported the mean reductions in mean K (K mean ) and maximum K (K max ) were less than 0.25 D, and K max decreased ≥ 1.00 D in 38 (33.6%) eyes during the 5 years follow-up. Most of the literatures reported that the K mean values were signi cant decreased from 0.13 D to 0.62 D [2,4,5].…”

“…Recently, the Avedro KXL system has been used for various types of corneal collagen cross-linking (CXL) for halting the progression of KC, including LASIK Xtra, epithelium-off (epi-off) accelerated CXL, and trans-epithelial (epi-on) accelerated CXL [2,3]. Nevertheless, patients treated with accelerated CXL (alone) show minimal visual improvement; subsequently, most patients do not achieve functional visual acuity [4][5][6].…”

“…Moreover, pediatric KC is a distinct entity; it is a more severe disease at the time of diagnosis and has a faster progression as compared to adult KC. Controversial outcomes have been reported on the use of epi-off continuous accelerated CXL treatment in KC [2,[4][5][6]. Today, the clinical evaluation of corneal epithelial thickness pro le is becoming more important in pre-clinical diagnosis and monitoring of KC.…”