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

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First Author: H.Kobashi JAPAN

Co Author(s):    H. Torii   I. Toda   S. Kondo   M. Itoi   K. Tsubota        

Abstract Details

Purpose:

In the current standard corneal collagen crosslinking treatment method, the epithelial debridement can cause severe pain and visual loss during the first few days after treatment. We developed the novel technology of violet light (VL) emitting glass which has the potential to prevent the progression of corneal ectasia without epithelial removal. We also defined the combination of VL irradiation and riboflavin treatment as KeraVio. To evaluate the clinical results of KeraVio in patients with progressive corneal ectasia.

Setting:

Minamiaoyama Eye Clinic and Dogenzaka Itoi Eye Clinic, Tokyo, Japan.

Methods:

Eyes exposed to VL (peak wavelength: 375 nm, irradiance: 310 μW/cm2) emitting glasses for 3 hours daily for 6 months, during which riboflavin solution (flavin adenine dinucleotide 0.05%) was simultaneously repeated 6 times during the VL irradiation under epithelium-on cornea. The primary efficacy criterion was the change over 6 months of topography-derived maximum keratometry (Kmax) value, comparing that over the preceding 1 year before baseline. Secondary outcomes evaluated were thinnest corneal thickness, stromal demarcation line, corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent, endothelial cell density, and adverse events.

Results:

Twenty eyes as severe progression were evaluated for the efficacy and all 40 eyes for the safety in the KeraVio treatment. The mean change in Kmax over the preceding 1 year before baseline and the during 6-month observation period was 6.03 ± 3.41 diopters (D) and -0.81 ± 3.34 D, respectively (P = 0.002). No significant progression was observed between baseline to 6-month (P = 0.985). At 6 months, the Kmax 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 mean change in CDVA and UDVA over 6 months was -0.07 ± 0.18 logMAR and -0.19 ± 0.50 logMAR, respectively. The corneal stromal demarcation line was identified in 16 eyes (80%) and its depth was 206.3 ± 54.9 μm at 1 month after treatment. No significant decrease in endothelial cell density was observed. No significant decrease in endothelial cell density, pterygium, skin melanoma, lenticular opacity, and transient corneal haze was noted in both eyes at the 6-month follow-up.

Conclusions:

Based on our 6-month results, daily treatment of progressive corneal ectasia with KeraVio can halt disease progression, without raising any concern for safety. KeraVio may be another minimally invasive treatment option for patients with corneal ectasia. Further long-term follow-up studies are needed to confirm these findings and to determine the optimal protocol in KeraVio procedure.

Financial Disclosure:

... is employed by a competing company, ... research is funded, fully or partially, by a company producing, developing or supplying the product or procedure presented, ... receives non-monetary benefits from a competing company