The corneal temperature elevation of 30 rabbits were measured with thermocouples during a series of retinal photocoagulations. Topical saline irrigation substantially reduced final temperature levels. The heat distribution over the illuminated cornea showed higher values centrally. Major temperature rises developed when the pupil was smaller than the cross section of the light beam. With a contact lens, temperature elevation is greatest and may reach 8 C for small pupillary apertures. To avoid high corneal temperatures during clinical photocoagulation, especially with a contact lens, frequent saline irrigations, a beam diameter smaller than the dilated pupil, and long intervals between the photocoagulation applications are required.
de Guillebon H, Pfister R, Govignon J, Pomerantzeff O, Schepens CL. Corneal Temperature Measurements During Retinal Photocoagulation. Arch Ophthalmol. 1971;85(6):712-717. doi:10.1001/archopht.1971.00990050714012