A comparison of alfaxalone and propofol on intraocular pressure in healthy dogs

Objective: To compare the effects of alfaxalone and propofol on intraocular (IOP) pressure in the canine eye.

Animals studied: Twenty-three healthy adult dogs.

Procedures: Dogs were randomized to receive intravenous propofol (n = 11) or alfaxalone (n = 12) until loss of jaw tone, 20 min after intravenous premedication (acepromazine 0.02-0.03 mg/kg and hydromorphone 0.05-0.1 mg/kg). IOP was measured at baseline (BL), 20 min postpremedication (postpremed), loss of jaw tone (postinduct), and immediately following orotracheal intubation (postintub). Between- and within-treatment effects were analyzed with two-way and one-way repeated measures ANOVA with Bonferroni's post hoc test, respectively. P < 0.05 was considered significant.

Results: No significant IOP differences were detected between alfaxalone or propofol groups at any time point (P > 0.05). Propofol: IOP did not change between BL (15.5 ± 2.7 mmHg) and postpremed (16.2 ± 3.6 mmHg, P > 0.05), or postinduct (19.1 ± 5.2 mmHg) and postintub (21.0 ± 4.6 mmHg, P > 0.05), but differed significantly between BL and postinduct (P < 0.0001), and postintub (P < 0.0001). Alfaxalone: IOP did not change between BL (15.7 ± 2.8 mmHg) and postpremed (15.3 ± 4.1 mmHg, P > 0.05), or postinduct (19.2 ± 4.9 mmHg) and postintub (20.5 ± 4.5 mmHg, P > 0.05), but differed significantly between BL and postinduct (P < 0.01), and postintub (P < 0.0001).

Conclusions: These data show a potentially clinically significant increase in IOP following induction with propofol or alfaxalone, but no difference between agents.