Topical ascorbic acid reduces myringosclerosis in perforated tympanic membranes. A study in the rat.

Myringosclerosis, a common finding after myringotomy, has been recently associated with an increased production of oxygen free radicals. Ascorbic acid's proposed actions include collagen synthesis, antioxidation, and free radical scavenging. The effects of topical ascorbic acid on healing tympanic membranes were studied. Particular attention was given to detecting the presence of myringosclerosis. Twelve Sprague-Dawley rats were bilaterally myringotomized. Their ears were randomized into group A, which received topical ascorbic acid in Gelfoam, group B, which received topical saline solution in Gelfoam, and group C, which received no treatment. The tympanic membranes were harvested on day 13, after routine otomicroscopy. Under light microscopy, the connective tissue layer of the untouched side of the pars tensa was distinctly thicker in group A than in group B or group C. At this level, the extent of sclerotic lesions was significantly less in the ascorbic acid-treated group. It is inferred that topical ascorbic acid reduces the occurrence of myringosclerosis following tympanic membrane perforations in the rat.