Abstract
Purpose :
The purpose of this study was to compare the initial tear lipid layer thickness (LLT) at baseline to the thickness 15 minutes after instilling an over-the-counter eye drop containing lipid in patients with meibomian gland dysfunction (MGD). Measurements were also performed using an over-the-counter formulation that did not contain a lipid.
Methods :
Potential subjects with MGD were prescreened with the SPEED questionnaire and biomicroscopic eye examination to determine eligibility. On the first study visit, a baseline LLT was measured using interferometry. The subject was asked to blink three times during the measurement in order to determine if blinking alone increased the LLT. Subjects continued to the second and third visits if the LLT was 75nm or less and had no more than 15nm increase in LLT following the three blinks. Thirty-five subjects returned for the second and third visits. At each visit, a baseline LLT was measured and an eye drop was instilled into each eye. The subjects were given a lipid eyedrop (Soothe XP, Bausch + Lomb, a division of Valeant Pharmaceuticals, North America) at one visit and a nonlipid eyedrop (Systane Ultra, Alcon Laboratories, Inc, Fort Worth, TX, USA) at the other visit. LLT was measured again 15 minutes after instillation. Visits were randomized so the data analysis was masked.
Results :
Analysis was done on the worst eye (having the lowest LLT at baseline) for each patient. The average baseline LLT before using a lipid containing eye drop was 49.46 ± 9.18 nm.
Fifteen minutes after instillation of the eye drop with lipid, the average LLT was 77.5 ± 29.3 nm, showing an increase of 28.04 ± 27.36 nm (p=<0.001). Of the 35 subjects, 22 had a LLT increase of 15nm or greater.
Fifteen minutes after instillation of the eye drop without lipid, the average LLT was 50.0 ± 12.9 nm which was not statistically significant from baseline (p=0.60). Of the 35 subjects, one subject had a LLT increase of 15 nm or greater.
Conclusions :
The lipid layer is the most anterior layer of the preocular tear film and is important for tear film stability and is dependent on meibomian gland function. Here we demonstrate that in subjects with MGD, lipid containing artificial tears increase the thickness of the lipid layer of the tears, while aqueous or nonlipid containing artificial tears do not make a significant difference in the LLT.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.