Level of reactive oxygen species in keratoconic eyes wearing scleral lenses

Oxidative stress and elevated reactive oxygen species (ROS) are implicated in corneal pathologies such as keratoconus. Understanding how scleral lens (SL) wear influence these mechanisms is important for optimizing patient management.

To assess the alteration in ROS level of keratoconic eyes wearing SL.

Ocular surface tears (T₀) were collected at baseline and 6 hours of lens wear (T₆) on Day 1 and 1 month from 26 keratoconic eyes. SL fluid reservoir (SL_FR) was collected after 6 hours of lens wear on Day 1 (SL_FR Day 1) and at 1 month (SL_FR 1 month). ROS levels were measured using fluorimetry from Schirmer's strip tear samples and the SL_FR samples. Visual acuity, Schirmer's values, and Ocular Surface Disease index questionnaire was also assessed.

The ROS levels of T₀ 1 month showed significant reduction after 6 hours of SL wear (p < 0.001). Similarly, the ROS level of SL_FR decreased after 1 month of SL wear compared to Day 1 (p = 0.007). ROS level in SL_FR at Day 1 and 1 month showed significant reduction when compared to T₀ 1 month value (p = 0.002, p < 0.001 respectively). A statistically significant increase in T₀ value was noted at 1 month time point when compared to day 1 values (p = 0.005). The baseline ROS levels were higher in collagen cross-linked eyes (p = 0.01), while non-collagen cross-linked eyes showed a reduction in ROS levels of SL_FR (p = 0.01) after 1 month of SL wear. Visual acuity and ocular surface disease index score showed significant improvement after 6 hours and 1 month compared to baseline (p < 0.001 and p < 0.001).

ROS level reduced in the SL_FR after 1 month and in tears after 6 hours with SL in KC patients. This indicates the effectiveness of SL in reducing ROS level of SL_FR which might have association with keratoconus pathogenesis, warrants further analysis.