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

Abstract

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 15 min, 1 h, 2 h, 4 h and 6 h 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 15 min after nanoemulsion drop instillation in the overall and inferior third of the tear film for subjects with baseline LLT values <50 nm. Average LLT values did not increase after use of the non-emollient. Symptoms of dryness improved up to 6 h 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.

Developing evidence-based guidance for the treatment of dry eye disease with artificial tear supplements: A six-month multicentre, double-masked randomised controlled trial

“…Relatively rapid and then sustained symptomatic relief occurred at the first month of use with both drops, which is consistent with the outcomes of previous studies with shorter follow up periods. [2,7,8,27,33] In the current study, symptomatic improvement plateaued after Day 30 and at the 6-month time point, both drops demonstrated statistically and clinically significant symptomatic improvements averaging a reduction of 11, 3-and 17-J o u r n a l P r e -p r o o f points in OSDI, DEQ-5 and SANDE scores, respectively. The relatively early onset of superior LWE improvements observed with both drops, which suggests reduced blinkrelated friction at the lid wiper, aligns favourably with the symptomatic improvement.…”

“…However, no effects were observed 15 minutes post-instillation, or after a month of four times daily instillation. [27] Other studies have also failed to detect differences in lipid layer thickness minutes to days post-instillation of these or other lipid-based drops. [28][29][30] Reasons for differences might relate to the nature of subjective lipid layer grading which reflects the dynamic distribution profile of the entire interpalpebral lipid layer, [31] rather than an average of absolute measures of lipid thickness calculated over a predefined area.…”

Oxygen Self-Supplying Nanotherapeutic for Mitigation of Tissue Hypoxia and Enhanced Photodynamic Therapy of Bacterial Keratitis

“…Because the eye is accessible and can be washed with high concentrations of topical antibiotics, eye drops are usually applied to these surface-associated infections and prevent the devastating complication of endophthalmitis. To delay the emergence of drug resistance, novel ocular nanotherapeutics should decrease the elimination process by enhancing the contact time and improving the bioavailability of nanotherapeutics. , Recently, evidence for nanoemulsions as ocular therapeutics has captured much attention owing to their thermodynamic stability and small particle size . Moreover, PDT as an non-antibiotic treatment has been applied in ocular disease. , …”

“…44,45 Recently, evidence for nanoemulsions as ocular therapeutics has captured much attention owing to their thermodynamic stability and small particle size. 46 Moreover, PDT as an non-antibiotic treatment has been applied in ocular disease. 47,48 To explore whether PFH/F-I resists bacteria efficiently in vivo, a rat "scratched cornea" and P. aeruginosa-infected model, which closely resembles keratitis, was designed.…”

Assessment of a Cationic Emulsion to Control the Tear Film Evaporation Rate

“… 26 In addition, nanoemulsion ocular solutions could increase the lipid layer thickness at 10 minutes post-instillation of the emulsion. 27 A recent study investigating tear lipid thickness using the tear film interferometry method found that the tear lipid thickness increased significantly with lipid tear supplements. 28 Therefore, this increase in lipid layer thickness may explain the reduction in tear film evaporation rate and improved tear film stability.…”