Measurement of the Retention Time of Two Different Carbomer-Based Ophthalmic Gels With and Without Hyaluronic Acid in Anesthetized Dogs Using Ultrahigh-Resolution Optical Coherence Tomography.

Abstract

PURPOSE: 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. MATERIALS AND METHODS: 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&#x2009;&#x3bc;L of each gel, then at 10, 15, 20, 25, 30, 35, 40, 45, 50, and 60&#x2009;min. CTFT evolution was analyzed by two-way repeated-measures ANOVA with normality testing and non-parametric correction when required. RESULTS: CTFT profiles significantly differed between formulations. Eye Lube Pro exhibited more sustained thickness than Ocry-gel. After 60&#x2009;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&#x2009;<&#x2009;0.001). No significant influence of sex, age, or brachycephalic phenotype was observed. CONCLUSIONS: 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.