Thermal orbital injuries from disposable cauteries

Forty rabbits divided in six groups and three brands of hot wire cautery with temperature ranging from 190 degrees C to 1035 degrees C were used in this experiment. A surgical procedure resembling a cosmetic blepharoplasty was performed on a total of 60 lower eyelids of the rabbits. The remaining eyelids were either shams or normal controls. Cautery application to orbital fat was carefully controlled, i.e., 10 or 20 seconds in single or double applications. Gross observation and microscopic examination of the biopsied specimens taken at 3 hours, 2 days, and 2 weeks after the procedures were performed. Evidence of thermal injury to the lacrimal gland and extraocular muscle damage was found. Although no evidence of thermal injury to the optic nerve was found, it was conceivable that either by a direct transfer of heat or by an indirect inflammatory and compressive effect the health of the optic nerve might be threatened. It is strongly recommended that hot wire cautery be used with extreme caution when working with orbital tissues.