Tear lipid supplement prophylaxis against dry eye in adverse environments

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.

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.

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.

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.