Randomized comparison of lipid‐containing and non‐lipid‐containing artificial tears on tear film dynamics over a 3‐month period

PURPOSE: To study the effects of a lipid-containing artificial tear (AT) and a non-lipid-containing AT on tear film dynamics over a 3-month period. METHODS: Subjects with low lipid layer thickness were randomized to lipid-containing or non-lipid-containing ATs for 3 months. At each visit Ocular Surface Disease Index (OSDI), LipiView, non-invasive and fluorescein tear breakup times, tear lipid layer and aqueous film recordings with EasyTear View+, and corneal staining assessment were performed. Lipid layer thickness and tear thinning rate were calculated using custom LabView programs. Mixed effects models were used to analyze relationships among variables. RESULTS: Thirty nine subjects completed the study. Mean EasyTear View+ lipid layer thickness with non-lipid-containing AT decreased from baseline (65.1 [61.0, 69.2] nm) to 3 months (58.0 [53.4, 62.7] nm, p = 0.012), whereas mean lipid layer thickness with the lipid-containing AT remained stable (baseline = 59.0 [53.6, 64.4] nm, 3 months = 62.4 [56.1, 68.7] nm, p = 0.30). There was a significant difference in lipid layer thickness change from baseline to 3 months between the lipid-containing (3.4 nm) and non-lipid-containing ATs (-7.1 nm, p = 0.014). Tear thinning rate with the non-lipid-containing AT was faster at 3 months (baseline = 3.01 [2.21, 3.81]%/sec, 3 months = 4.78 [3.62, 5.94]%/sec, p = 0.008), but remained stable with the lipid-containing AT (baseline = 2.84 [1.93, 3.76]%/sec, 3 months = 2.93 [2.15, 3.70]%/sec, p = 0.84). The increase in tear thinning rate from baseline was greater with the non-lipid-containing (1.77%/sec) than the lipid-containing AT (0.09%/sec, p = 0.019). Fluorescein tear breakup time with the non-lipid-containing AT remained stable at 3 months (4.70 [4.14, 5.25] sec) versus baseline (4.23 [3.48, 4.99] sec, p = 0.26), whereas fluorescein tear breakup time with the lipid-containing AT was longer at 3 months (6.33 [4.85, 7.82] sec) versus baseline (4.44 [3.66, 5.22] sec, p = 0.029). There were no significant changes in OSDI score, LipiView lipid layer thickness, non-invasive tear breakup time or corneal staining grade over the 3-month period. CONCLUSIONS: Patients with lipid deficiency may benefit from lipid-containing AT over the non-lipid-containing AT to stabilize tear lipid thickness and minimize tear thinning while increasing tear breakup time. TRIAL REGISTRATION: This study was registered at ClinicalTrials.gov (#NCT05705518) on the date of January 20, 2023.