Clinical results of transepithelial corneal collagen cross-linking for pediatric keratoconus

Background

Keratoconus is a progressive corneal thinning and protrusion disease that develop in the age of puberty, resulting in a certain extent impairment of visual function.Corneal collagen cross-linking (CXL) increases the stiffness of the cornea through the photooxidation of ultraviolet A (UVA) and riboflavin, with the aim to postpone and prevent the progression of keratoectasia.

Objective

This study was to evaluate the safety and efficacy of transepithelial CXL in the treatment of pediatric keratoconus.

Methods

Ten eyes of 9 pediatric patients with keratoconus undergoing transepithelial CXL were enrolled from February 2010 to March 2013 in Affiliated Eye Hospital of Wenzhou Medical University, with the mean age was (15±1) years (range from 13 years to 17 years). After topical anesthesia (0.1% tetracaine) for 15 minutes, 0.5% riboflavin was applied until it was saturated in the anterior chamber, then UVA with the intensity of 3 mW/cm² was performed on the cornea for 30 minutes.The uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, topography, corneal thinnest thickness were measured 7 days, 1 month, 3 months, 6 months and 1 year after operation.Endothelium cell density (ECD) was measured 7 days after operative.

Results

The mean corneal reepithelization time was (1.4±0.8) days.The UDVA and CDVA were significantly improved from preoperative 1.02±0.16 and 0.34±0.20 to postoperative 0.77±0.18 and 0.25±0.15, respectively (t=4.251, 3.750; both at P<0.05). The refractive sphere and spherical equivalent significantly changed from preoperative (-7.15±3.00)D and (-9.26±3.23)D to postoperative (-5.28±2.05)D and (-7.05±2.08)D 1 year, respectively (t=-2.515, -2.597; both at P<0.05). Maximum K-value (K_max) was significantly decreased from preoperative (64.1±11.9)D to postoperative (61.8±10.4)D (t=2.304, P<0.05). The refractive cylinder, corneal thinnest thickness and ECD showed no significant differences between preoperation and postoperation (t=-1.331, 0.328, 1.205; all at P>0.05). Stromal opacity was observed in 2 eyes 3 months and 6 months after operation, respectively.

Conclusions

Transepithelial CXL is safe and effective in prolonging or halting progression in adolescent keratoconus.

Keratoconus; Transepithelial; Corneal collagen cross-linking; Adolescent; Ocular/Treatment outcome