Changes in intraocular pressure during propofol anesthesia

10 September 2018 – News

Evidence suggests that some anesthetic drugs increase intraocular pressure (IOP) which could lead to complications, including the loss of globe contents through surgical or traumatic wounds and/or blindness.

A study set out to establish the IOP cut-off values that could be used to diagnose glaucoma, as well as to observe the effects of propofol anesthesia in IOP in animals, with and without premedication. It included a total of 234 client-owned dogs which were divided into 2 groups: healthy dogs submitted to IOP measurements to establish IOP values and dogs scheduled for ophthalmic surgery, with or without premedication (butorphanol and midazolam).

The results suggested that an IOP of more than 25mmHg should be used as a cut-off point for glaucoma.  In non premedicated dogs without glaucoma, there was a significant increase in IOP following the administration of propofol, but premedication was found to reduce its effects.  In animals with glaucoma, both premedication and propofol seemed to reduce the intraocular pressure.

While the number of animals with glaucoma is small, the authors consider that further research into how anesthetic drugs can influence IOP is important.

In Effects of propofol on intraocular pressure in premedicated and non premedicated dogs with and without glaucoma; Terah R. Webb, Milton Wyman, Julie A. Smith, Yukie Ueyama, and William W. Muir; Journal of the American Veterinary Medical Association 2018