Efficacy and Safety of KeraVio using Violet Light-Emitting Glasses and Cyanocobalamin Drops for Progressive Keratoconus: A Pilot Study

Purpose To evaluate the efficacy and safety of KeraVio treatment, a minimally invasive corneal cross-linking technique that combines cyanocobalamin eye drops with violet light (VL) irradiation, in patients with progressive keratoconus. Methods This prospective, single-arm exploratory study included three patients (mean age, 36.67 ± 11.24 years; 2 males, 1 female) with progressive keratoconus. Treatment consisted of 0.02% cyanocobalamin eye drops administered six times daily and VL irradiation via TLG-003 eyeglasses worn 4.5 hours per day for three months. Patients were followed for six months. The primary endpoint was the change in maximum keratometry (Kmax). Secondary endpoints included thinnest corneal thickness (TCT), demarcation line (DL), best-corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), manifest refraction, intraocular pressure, corneal endothelial cell density, corneal haze, slit-lamp/fundus examination findings, and periocular skin changes. Results The mean Kmax change at 6 months was − 0.37 ± 6.82 D. The mean change in the TCT was − 7.33 ± 19.66 µm. BCVA and UCVA remained stable (mean BCVA change: −0.03 ± 0.15 logMAR; mean UCVA change: 0.04 ± 0.07 logMAR). No clinically observed changes in refraction, intraocular pressure, endothelial cell density, corneal clarity, or retinal findings were detected. No adverse events occurred. Conclusions KeraVio treatment with cyanocobalamin drops appeared to be safe for use in this small cohort. However, owing to the limited sample size and variable Kmax responses, further large-scale, controlled studies are needed to determine the efficacy of this treatment in the context of halting keratoconus progression. Trial registration number: jRCTs032230104 Registration Date: June 1st, 2023.