Background: General anesthesia in cats causes a transient decrease in tear production, necessitating the use of topical lubricants to protect the cornea; however, comparative data on the rate at which different lubricants normalize tear production are limited. This study compared the effect of two different ophthalmic preparations based on sodium hyaluronate and carbomer on tear secretion in cats under general anesthesia. 
&nbsp; 
Methods: The study was conducted using a contralateral eye model in 12 clinically healthy female cats scheduled for spay surgery under xylazine-ketamine-isoflurane anesthesia. Immediately after intubation and confirming the level of surgical anesthesia, one drop of a sodium hyaluronate-containing preparation was applied to the right eye (Group H) and a rice-sized amount of a carbomer-containing preparation was applied to the left eye (Group C). Tear production was measured quantitatively using the Schirmer Tear Test at specific time points before any sedation (T0), during and after anesthesia (T15-T60&nbsp;and T+15-T+60, respectively). 
&nbsp; 
Result: Anesthesia caused a statistically significant decrease in Schirmer Tear Test values compared to baseline in both the groups (p&lt;0.05). At 30 minutes post-anesthesia (T+30), the mean Schirmer Tear Test value in Group H (15.08 &plusmn; 2.71 mm/min) was significantly higher than that in Group C (11.00 &plusmn; 3.54 mm/min) (p&lt;0.05). At 60 minutes post-anesthesia (T+60), STT values returned to baseline in Group H, while full recovery was not observed in Group C. In conclusion, this study demonstrated that both sodium hyaluronate/dexpanthenol eye drops and carbomer-based eye gel were effective in providing immediate protection to the ocular surface during anesthesia and accelerating recovery after anesthesia, but the sodium hyaluronate formulation provided a significantly faster recovery of tear production to baseline levels in the early post-anesthesia period.

A Comparative Evaluation of Sodium Hyaluronate- and Carbomer-based Ophthalmic Preparations on Tear Production in Cats under General Anesthesia