Abstract
Purpose :
Collagen crosslinking arrests the progression of keratoconus, but the conventional epithelial off technique with the Dresden protocol of 3 mW/cm2 for 30 minutes is associated with significant pain, risk of haze, and considerable physician time. This study explores the initial outcomes of an IRB-approved Phase 1 trial of epithelial on crosslinking with a pulsed (5 seconds on, 5 seconds off) accelerated (30 mW/cm2 for 6 minutes) protocol.
Methods :
All patients were treated with respect to the ARVO Declaration and the Declaration of Helsinki. After IRB approval, informed consent, and screening with respect to inclusion and exclusion criteria, patients were enrolled in this Phase 1 study of the Peschke PXL-330 with transepithelial riboflavin solution. After topical proparacaine application, topical riboflavin solution was administered every 2 minutes for 40 minutes. The patient was then placed under the crosslinking illuminator, where UV light of 365 nm wavelength was applied at 30 mW/cm2 fluence with pulsing. A subset of patients underwent concurrent placement of Intacs. A bandage contact lens was placed at the conclusion of the procedure.
Results :
17 eyes of 11 patients have been treated. 8 eyes were treated with crosslinking alone, and 9 eyes treated with Intacs + crosslinking. No adverse events (e.g. haze, epithelial sloughing, infiltrate, or melt) have been observed. No loss of best corrected visual acuity occurred in any patient, while mean best corrected visual acuity increased by 1 line. At 6 months of follow-up, there is an average demarcation line depth of 253.4 microns. In the crosslinking-alone cohort, maximum keratometry declined by 0.795 diopters and inferior superior keratometric difference declined by 1.57 diopters. In the Intacs + crosslinking group, greater corneal flattening and reduction of astigmatism was observed as predicted: 4.193 diopters of flattening of maximum keratometry and 3.213 diopters in reduction of inferior-superior difference. No adverse events were observed when Intacs was performed as a concurrent procedure with corneal crosslinking.
Conclusions :
Early follow-up indicates that pulsed, accelerated, epithelial-on crosslinking is safe for keratoconus treatment and may be comparably effective to conventional crosslinking. Intacs can be safely performed at same time as corneal crosslinking with similar efficacy as published reports of intrastromal corneal ring placement.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.