Clinical outcomes of KeraVio using violet light: emitting glasses and riboflavin drops for corneal ectasia: a pilot study

Background/aims We developed a novel technology consisting of violet light (VL)-emitting glasses and defined the combination of VL irradiation and riboflavin treatment as KeraVio. Our goal was to evaluate the clinical results of KeraVio in patients with progressive corneal ectasia. Methods Eyes were exposed to VL (375 nm, irradiance 310 μW/cm2)-emitting glasses for 3 hours daily for 6 months, and a riboflavin solution was administered onto the corneal epithelium six times during each 3-hour VL irradiation. The primary end point was a change in the maximum keratometry (Kmax) value over 6 months compared with that over the 1 year before baseline. Results The efficacy of KeraVio was evaluated in 20 eyes with severe progression, and its safety was evaluated in all 40 eyes. The mean changes in Kmax over the 1 year before baseline and during the 6-month observation period were 6.03±3.41 dioptres (D) and −0.81±3.34 D, respectively (p=0.002). At 6 months, the Kmax value decreased by more than 2 D in 4 eyes (20%), remained within 2 D in 13 eyes (65%), and increased by 2 D or more in 3 eyes (15%). The corneal stromal demarcation line was identified in 16 eyes (80%), and its depth was 206.3±54.9 μm at 1 month. No significant decrease in endothelial cell density, lenticular opacity or transient corneal haze was noted. Conclusion Based on our 6-month results, daily treatment of progressive corneal ectasia with KeraVio can halt disease progression without any safety concerns. Clinical trial registration number jRCTs032180217.