Thermostatically-controlled microwave used for treatment of internal

Abstract

A miniaturized microwave applicator comprises a thin-wall metal dielectric-filled waveguide having a thermocouple preferably disposed in a groove in the surface of the dielectric radiating aperture of the waveguide when the aperture is placed in contact with a spot on the outer surface of the conjunctiva or sclera overlying the type of given internal tissue of the eye, such as the ciliary body or chorioretinal tissue, which has a relatively high water content compared to conjunctival or scleral eye tissue. This permits cyclodestruction of the ciliary body, as a treatment for glaucoma, by heat generated by absorbed microwave energy radiated thereto during a given time. It also permits microwave heating to repair a detached retina by chorioretinal scar formation. Damage due to overheating of the tissue is prevented by the thermocouple, which monitors the conjunctival or sclera surface temperature, being used to thermostatically control the microwave energy supplied to the waveguide in a manner that the conjunctival or scleral tissue temperature is maintained substantially constant at a value below that which would cause damage thereto. The desired operation is dependent on the fact that very little of the microwave energy is absorbed by the low-water-content conjunctival or scleral tissue as it passes therethrough, but is highly absorbed by the underlying high-water-content of the given internal tissue.