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

Abstract

Purpose

To evaluate the efficacy of oral riboflavin and sunlight exposure in stabilizing keratoconus progression.

Methods

In 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.

Results

Fifty 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).

Conclusion

After 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.