A comparison between diathermy and cryotherapy was made in lesions which were placed in single eyes of adult, albino rabbits. The effects on both the retinal and choroidal vessels were stressed. Moderate to heavy dosage was used. Cryoprobe application caused immediate retinal and choroidal hemorrhage which slowly resorbed during the first week. Diathermy caused a hemostatic, coagulative effect on the retinal vessels. Diathermy to the choroid caused initial hemorrhage and hyperemia which was distributed in a circumferential pattern around a central, avascular, coagulated area. Both diathermy and cryotherapy caused obliteration of the smaller retinal and choroidal vessels. Diathermy resulted in a more adherent and "stickier" early chorioretinal adhesion than cryotherapy. Heparin had little effect on the hemorrhagic tendency of either diathermy or cryotherapy.
Miller JB. Ocular Diathermy and CryocoagulationResultant Retinal and Choroidal Vascular Changes. Arch Ophthalmol. 1971;85(3):339-349. doi:10.1001/archopht.1971.00990050341020