The assessment of orbital apical temperature change with local cool compress application

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

A six-month-old, 220-pound Landrace/Hampshire/Duroc mixed breed pig was intubated and maintained under anesthesia with a steady average body temperature. An incision in the lateral third of the right lower eyelid along the inferior orbital rim was made, and a digital thermometer was inserted and guided toward the orbital apex by fluoroscopic imaging of the orbit. After the baseline apical temperature was measured, an 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.

At an average core body temperature of 38.9°C, the baseline apical temperature was 37.2°C. After placement of a 0°C 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°C from baseline. The same apical temperature noted 20 minutes after placement of the cool compress was measured 45 minutes after ice/water compress placement.

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