Can Rhodiola rosea supplementation mitigate digital eye strain? A triple-blinded placebo-controlled study

Abstract

Purpose: This study aimed to assess the impact of Rhodiola rosea (RR) supplementation on the dynamics of the accommodative response and digital eye strain (DES) symptoms following 30-min visual tasks with different levels of cognitive demand. Methods: Eighteen young adults (mean age±SD: 24.6±4.0years) participated in this placebo-controlled, triple-blind, balanced crossover study. Participants completed four sessions separated by 1week in a randomised order. The sessions differed in the supplement (RR or placebo) and cognitive demand of the visual task (Stroop test or control video). The supplementation consisted of 1200mg of RR or placebo per day for 4days (two 300mg capsules every 12h) and a washout period of 3days was allowed before the subsequent condition. The lag and variability of the accommodative response were measured at 500, 40 and 20cm using an open-field autorefractor, and DES symptoms were assessed using a 10-item questionnaire. Results: RR supplementation caused a reduction in the variability of accommodation (p=0.007) and the perceived levels of ‘Blurred vision when looking into the distance at the end of the near task’ (p=0.009). However, the lag of accommodation (p=0.15) and the remainder of the DES symptoms were unaffected by the ingestion of RR (p>0.05 in all cases). The reduction in the variability of accommodation after RR intake was observed at 40 and 20cm (p-values <0.001 and 0.04, respectively), but not at far distance (500cm, p=0.40). Conclusions: These findings show that RR supplementation (1200mg/day for 4days) produced a reduction in the variability of accommodation and one of the assessed DES symptoms, suggesting that it could be considered as a potential strategy to prevent or manage DES. However, further research is needed to determine its clinical relevance and optimise dosage and timing.