• Microwaves were used to induce chorioretinal scar formation in normal rabbit eyes. We have developed a directional 6.8-gigahertz microwave applicator with a rectangular aperture. It was designed to mimic the shape and function of a T-shaped scleral depressor. For treatment, the applicator was placed on the conjunctiva over the sclera. Then, indentation was used to visualize probe placement during indirect ophthalmoscopy. Thermocouple-controlled heating was initiated such that conjunctival temperatures in a range of 51°C to 65°C were induced for 10 seconds per treatment. We found that treatment at temperatures of 51°C or 52°C for 10 seconds produced circular areas of acute retinal whitening. From these microwave-induced lesions, there evolved chorioretinal attenuation with and without evidence of retinal pigment epithelial hyperplasia. No evidence of scleral damage was noted at these thermal doses.
Finger PT, Svitra PP, McCormick SA, Presser A. Microwave Diathermy of the Retina and Choroid. Arch Ophthalmol. 1993;111(2):254-258. doi:10.1001/archopht.1993.01090020108033