Oral riboflavin supplementation and sunlight exposure: A possible novel and accessible approach to stabilize progressive keratoconus

PurposeTo evaluate the efficacy of oral riboflavin and sunlight exposure in stabilizing keratoconus progression.MethodsIn this prospective interventional study with a retrospective historical control group, patients with progressive keratoconus received 60 mg/day of oral riboflavin and 30 min/day of sunlight exposure for three months. A historical control group included patients with similar characteristics who were awaiting cross-linking or keratoplasty. Ophthalmological exams and corneal topography were conducted at baseline, 6 months, and 12 months post-treatment. A sub-analysis was performed for patients with corneal stromal thickness (CST) ≥ 400 µm and < 400 µm.ResultsFifty patients [91 eyes; 31 (62%) males] with a mean age of 18.7 ± 4.4 years (range, 11-31) and a mean maximum keratometry (Kmax) of 57.9 ± 8.3 D comprised the treatment group. Kmax flattened (-1.22 ± 4.78 D; P = 0.003) in treated eyes; however, it steepened (+0.32 ± 11.96 D; P = 0.455) in controls at 6 months. Keratoconus progression occurred in 27.5% of treated eyes versus 49.5% in controls (P = 0.002). Eyes with CST ≥ 400 µm had a 3.85-fold higher risk of progression in the control group than in treated eyes (95% CI: 1.6-9.3; P = 0.001).ConclusionAfter one year, 72.5% of treated eyes remained stable following the use of oral riboflavin and sunlight exposure, with a significantly lower risk of progression in eyes with normal CST.