Effects of Argon Laser Irradiation on the Utricular Macula

Abstract

Guinea pig utricular maculae were irradiated by Argon laser (1.0W × 1.0s, spot size 100 μm) through the oval window under an operating microscope without touching the perilymph. The stapes was replaced at the oval window after irradiation. The inner ear was studied morphologically and physiologically. Immediately after the irradiation, hair cells, supporting cells, and nerve fibers of the utricular macula disappeared in a shot area of 100 μm in diameter. The otolith remained unchanged.
Seven weeks after the irradiation, the utricular macula with the nerve fiber had completely disappeared. Other parts of the inner ear were morphologically unchanged. The compound action potential indicated normal cochlear function.