A Novel Oxygen Chamber for Corneal Cross-Linking in a High-Oxygen Environment: A Pilot Study and Clinical Outcomes

To evaluate the safety and efficacy of increased environmental oxygen using a novel oxygen chamber during corneal cross-linking (CXL) in patients with keratoconus (KCN).

This prospective interventional pilot study included 20 eyes from 15 patients with documented progressive KCN. Patients underwent epithelium-off accelerated CXL (irradiance of 9 mW/cm² for 10 min) in two different environments. The study group received CXL using an oxygen chamber providing a high-oxygen environment (60%), while the control group underwent CXL under ambient oxygen conditions (21%). Outcome measures included visual and topographic outcomes, demarcation line depth, endothelial cell count, and dry eye evaluation. Follow-up visits were conducted up to 6 months post-CXL.

Seventeen eyes completed the follow-up (study: 10 and control: 7). At 1-month postoperation, the study group exhibited a significantly deeper demarcation line, particularly at the inferior 3 mm location (250.8 μm vs. 169.3 μm, P = 0.03). At 6 months post-CXL, keratometry values improved more in the study group, with K₁ and K_m showing a significant decrease from baseline (P = 0.046 and 0.047, respectively). Best-corrected visual acuity and refraction remained stable in both groups throughout the 6-month follow-up (P > 0.05). The endothelial cell count decreased less in the study group compared to the control group (-136.1 ± 52.3 vs. -288.9 ± 100.9, P = 0.16).

The findings of this pilot study show that the novel oxygen chamber can safely and effectively enhance CXL outcomes by creating a hyperoxic environment.