One-Year Follow-Up of Corneal Biomechanical Changes After Accelerated Transepithelial Corneal Cross-Linking in Pediatric Patients With Progressive Keratoconus

Abstract

Aims: This study aimed to investigate the corneal biomechanical changes and topographic outcomes of accelerated transepithelial corneal cross-linking (ATE-CXL) in pediatric progressive keratoconus.Methods: In this prospective longitudinal study, 31 eyes of 28 pediatric patients with keratoconus (21 boys and 7 girls; mean age, 14.35 ± 2.68 years) undergoing ATE-CXL (epithelium-on procedure with 45 mW/cm2 for 320 s) were included. Corvis ST was used to measure dynamic corneal response parameters at baseline and at 12 month after ATE-CXL. Corneal keratometry and corneal thickness were measured using Pentacam pre-operatively and 1, 6, and 12 month post-operatively.Results: No serious complications occurred during or after ATE-CXL. The maximum keratometry values were 60.10 ± 7.51 D pre-operatively and 61.42 ± 8.92, 61.17 ± 7.96, and 60.02 ± 7.58 D at 1, 6, and 12 month after ATE-CXL (P > 0.05), respectively. Corneal thickness remained stable during the 12-month follow-up (P > 0.05). At post-operative 12 month, first applanation time (P < 0.001), first applanation length (P = 0.004), second applanation velocity (P = 0.014), highest concavity time (P = 0.022), and radius of curvature at highest concavity (P = 0.031) increased significantly. The value of stiffness parameter at first applanation was significantly increased from 57.70 ± 27.57 pre-operatively to 63.36 ± 27.09 at 12 months after ATE-CXL (P = 0.018).Conclusions: ATE-CXL is safe and effective in stabilizing the progression of pediatric keratoconus. Changes in corneal biomechanical response consistent with stiffening following ATE-CXL were observed in pediatric patients with keratoconus.

Evaluation of Dynamic Corneal Response Parameters and the Biomechanical E-Staging After Accelerated Corneal Cross-Linking in Keratoconus

“…A third study, however, did not find a change of SP-A1 in 18 patients that were followed-up for up to 4 years after CXL according to the Dresden protocol 13. An increase in SP-A1 was also observed postoperatively in transepithelial accelerated CXL 17. An increasing corneal stiffness after CXL seems plausible, as CXL has been reported to result in an increase in collagen fiber diameter of about 12% in the anterior corneal stroma 18.…”

“…13 An increase in SP-A1 was also observed postoperatively in transepithelial accelerated CXL. 17 An increasing corneal stiffness after CXL seems plausible, as CXL has been reported to result in an increase in collagen fiber diameter of about 12% in the anterior corneal stroma. 18 The current study found comparable values preoperatively and postoperatively for SP-A1 within the first months after CXL, a slightly higher SP-A1 value after 11 months and a significantly higher SP-A1 value 23 months after CXL.…”

Analysis of Tear Function Outcomes following Collagen Cross-Linking Treatment in Ectatic Corneas

“…Kmax increased at 1 month after epi-on and epi-off CXL, but BCVA also increased. In Weijun Jian's study, the Kmax values were 60.10 ± 7.51 D preoperatively and 61.42 ± 8.92, 61.17 ± 7.96, and 60.02 ± 7.58 D at 1, 6, and 12 months after accelerated transepithelial CXL ( P =0.05), respectively [ 22 ]. Kmax in the early postoperative period was also higher than that before surgery.…”