Comparison of nanoemulsion and non-emollient artificial tears on tear lipid layer thickness and symptoms.

Purpose: Dry eye disease (DED) is often managed with over-the-counter eye drops. This study evaluated the diurnal effects of a single drop of two ocular lubricants (nanoemulsion vs. non-emollient) on tear film lipid layer thickness (LLT) and symptoms of ocular dryness. Subjects were also assessed after 1 month of nanoemulsion eye drop use.

Methods: Part 1 was a cross-over comparison of a nanoemulsion and a non-emollient eye drop. LLT and dry eye symptoms were measured at baseline and at 15min, 1h, 2h, 4h and 6h after instillation of each drop. Part 2 was a 1-month observational study assessing LLT and symptoms after 30-day use of the nanoemulsion drop four times daily (qid).

Results: Total of 20 subjects completed the study (mean age=45.6±7.9, 15 female). Part 1 found a significant increase in average LLT 15min after nanoemulsion drop instillation in the overall and inferior third of the tear film for subjects with baseline LLT values <50nm. Average LLT values did not increase after use of the non-emollient. Symptoms of dryness improved up to 6h following instillation of both drops. Part 2 results found that using the nanoemulsion eye drop for 1 month improved symptoms reported on symptom surveys.

Conclusion: Nanoemulsion eye drop use increased average LLT in subjects with low baseline levels. Statistically and clinically significant improvement in symptoms were found on symptom surveys after qid-use (four times a day) of the nanoemulsion drop. Results suggest that a nanoemulsion eye drop can benefit subjects with dry eye symptoms.