title: Microwave diathermy of the retina and choroid.
abstract: 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 degrees C to 65 degrees C were induced for 10 seconds per treatment. We found that treatment at temperatures of 51 degrees C or 52 degrees 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.
authors.affiliation: Department of Ophthalmology, North Shore University Hospital-Cornell University Medical College, Manhasset, NY 11030.
authors.forename: P T
authors.initials: PT
authors.lastname: Finger
authors.forename: P P
authors.initials: PP
authors.lastname: Svitra
authors.forename: S A
authors.initials: SA
authors.lastname: McCormick
authors.forename: A
authors.initials: A
authors.lastname: Presser
mesh_terms: D000818:Animals; D001706:Biopsy; D002829:Choroid / Q000601:surgery*; D002921:Cicatrix / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D003972:Diathermy / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D004195:Disease Models, Animal; D005069:Evaluation Studies as Topic; D005451:Fluorescein Angiography; D009887:Ophthalmoscopy; D011817:Rabbits; D011829:Radiation Dosage; D012160:Retina / Q000601:surgery*; D013696:Temperature; D013817:Thermography; D013997:Time Factors