Effect of different artificial tears on tear film parameters in dry eye disease

Significance: Artificial tears remain the cornerstone for managing dry eye disease. The current study's real-world efficacy test of carboxymethylcellulose (CMC), polyethylene glycol (PEG) 400, or sodium hyaluronate (SH)-based lubricants highlights their similar effects on noninvasive tear film parameters over the short term. However, patients reported better relief with SH-based lubricants.

Purpose: This study aimed to compare the short-term impact of different artificial tear formulations on tear film in moderate dry eye disease patients.

Methods: A prospective, double-masked, controlled study randomly allocated moderate dry eye disease patients into five groups of artificial tears: 0.5% CMC, 1% CMC, 0.1% SH-trehalose, 0.4% PEG 400-0.3% propylene glycol (PG), and 0.1% SH-0.4% PEG 400-0.3% PG. Noninvasive tear breakup time (NIBUT), tear meniscus height, and bulbar redness (Keratograph 5M; OCULUS Optikgeräte, Wetzlar, Germany) were assessed (in a controlled environment chamber 68 to 70°F; 35% relative humidity) at baseline and every 15 minutes for 1 hour after a drop instillation in the left eye. The right eye was an internal control. At 1 hour, subjects were asked for a change in subjective symptomatology (scales 0 to 4). A linear mixed-effect model was used for analysis.

Results: Each artificial tear group had 20 patients (100 patients). All groups had similar dry eye disease types and durations, baseline ocular surface disease index scores, and tear film parameters. All artificial tears showed significant improvement in NIBUT values at all time points from baseline compared with contralateral eyes. The change in NIBUT values was similar between different artificial tears at all time points. Bulbar redness scores and tear meniscus height showed no significant change in either eye with time or artificial tears. All patients reported improvement in dry eye disease symptomatology, with significant differences observed between 1% CMC and SH-PEG-PG (p=0.01), 0.5% CMC and SH-PEG-PG (p<0.0001), and 0.5% CMC and 0.1% SH-trehalose (p=0.01), where SH-based tear drops performed better.

Conclusions: Tear film stability improves following a single drop of CMC, SH, and PEG-based artificial tears, although these artificial tears do not differ in their short-term effect.