Tear lipid supplement prophylaxis against dry eye in adverse environments

Abstract

Purpose: To compare the prophylactic efficacy of single application of lipid and non-lipid containing tear supplements, prior to exposure of symptomatic dry eye subjects to a simulated adverse environment.

Methods: Thirty subjects with mild-to-moderate dry eye symptoms participated in the prospective, randomised, double-masked, paired-eye trial. A lipomimetic drop (Systane^® Balance) was applied to one eye (randomised), and a non-lipid containing drop (Systane^® Ultra) applied simultaneously to the contralateral eye. Subjects were subsequently exposed to a validated simulated adverse environment model created by a standing fan directed towards the eye, at a distance of 1m, for 2.5min. Low contrast glare acuity, lipid layer grade (LLG), non-invasive tear break-up time (NIBUT), temperature variation factor (TVF), and tear meniscus height (TMH) were evaluated at baseline, following eye drop instillation and following simulated adverse environment exposure.

Results: Both therapies resulted in increased NIBUT (both p<0.001), and prevented its decline below baseline with simulated adverse environment exposure (both p>0.05). However, only the lipomimetic drop increased LLG (p<0.001) and precluded its fall below baseline post-adverse environment exposure (p=0.15). Furthermore, post-instillation and post-exposure LLGs and NIBUT were significantly higher in the lipomimetic group (all p<0.05). No significant changes were observed in glare acuity, TVF and TMH (all p>0.05). More subjects (67%) reported greater ocular comfort in the eye receiving the lipomimetic.

Conclusions: Single application of both lipid and non-lipid containing eye drops conferred protective effects against exposure to adverse environmental conditions in subjects with mild-to-moderate dry eye, although the lipomimetic demonstrated superior prophylactic efficacy.

Keywords: Artificial tears; Dry eye; Lipid layer; Lipid supplement; Tear film; Tear film stability.