Orbital Apical Temperature Change in Relation to a Local Cool Compress Therapy

Abstract

Purpose: : To examine the change in orbital apical temperature over time, with a local ice/water admixture compress placed over the eyelid.

Methods: : A six month old, 220 pounds Landrace/Hampshire/Duroc mix-breed pig was intubated and maintained under isoflurane gas anesthesia with an average body temperature of 38.9 degrees Celsius. The research was conducted in compliance with the ARVO statement for the use of animals in ophthalmic and vision research and the declaration of Helsinki, and was approved by the institutional review board. A 15 Bard-Parker blade was used to make an incision in the lateral third of the right lower eyelid along the inferior orbital rim. A digital thermometer (Trutemp Model #3519) was inserted into the incision and guided towards the orbital apex by fluoroscopic imaging of the orbit. After measuring the baseline apical temperature, ice/water admixture compress was placed on the right eyelid and serial temperatures were taken every 5 minutes for 20 minutes. A final measurement was taken at 45 minutes after the ice/water admixture compress placement.

Results: : At an average core body temperature of 38.9 degrees Celcius, the baseline apical temperature was 37.2 degrees Celcius. After placement of a 0 degrees Celcius ice/water admixture, there was an exponential decrease in apical temperature, reaching a plateau after a period of 20 minutes, with a decrease of 1.4 degrees Celcius from baseline. The same apical temperature noted 20 minutes after placement of the cool compress, was measured 45 minutes after ice/water compress placement.

Conclusions: : There was only a limited decrease in apical temperature by placing a local 0 degrees Celcius ice/water admixture over the eyelid. This information is useful in determining whether local hypothermia may be a potential alternative for traumatic optic neuropathy.

Keywords: orbit • optic nerve • trauma