Measurement of the Retention Time of Two Different Carbomer-Based Ophthalmic Gels With and Without Hyaluronic Acid in...

To evaluate the stability of two ophthalmic gels-one containing carbomer alone (Ocry-gel), and the other combining carbomer with sodium hyaluronate (Eye Lube Pro)-on the corneal surface of anesthetized dogs, using spectral-domain optical coherence tomography (SD-OCT) to quantify Central Tear Film Thickness (CTFT) over time.

Twenty healthy dogs undergoing general anesthesia for non-ocular routine procedures were included in a randomized controlled study. Each dog received Ocry-gel in one eye and Eye Lube Pro in the contralateral eye, according to a randomization protocol. CTFT was measured with ultrahigh-resolution anterior segment SD-OCT before (T0) and after (T1) administration of 200 μL of each gel, then at 10, 15, 20, 25, 30, 35, 40, 45, 50, and 60 min. CTFT evolution was analyzed by two-way repeated-measures ANOVA with normality testing and non-parametric correction when required.

CTFT profiles significantly differed between formulations. Eye Lube Pro exhibited more sustained thickness than Ocry-gel. After 60 min, CTFT remained measurable in 14/20 dogs for Eye Lube Pro versus 2/20 for Ocry-gel. Statistical analysis confirmed significantly higher CTFT for Eye Lube Pro at most time points (p < 0.001). No significant influence of sex, age, or brachycephalic phenotype was observed.

Addition of sodium hyaluronate to a carbomer-based gel significantly prolongs pre-corneal retention time in anesthetized dogs. These results suggest that selecting the protective gel should consider anesthesia duration or guide adjustment of administration frequency.