Topical application of calcium channel blockers to reduce the progression of experimentally induced myringosclerosis and tympanosclerosis

OBJECTIVES: This study aimed to evaluate the ability of topically applied calcium channel blockers (diltiazem) to reduce the progression of experimentally induced myringosclerosis and tympanosclerosis. STUDY DESIGN: Animal model. Experimental prospective study. METHODS: The study included 25 adult albino guinea pigs that were bilaterally myringotomized and inoculated with a suspension of Streptococcus pneumonia type 3. The right ears were treated with topical application of diltiazem, and the untreated left ears served as the control group. Otomicroscopy and remyringotomy were conducted every week. One animal was sacrificed after 1 week and the remaining at the end of 6 weeks. Temporal bones were dissected, and tympanic bullae were analyzed with light microscopy. RESULTS: The untreated control ears showed evidence of extensive myringosclerosis on otomicroscopy, and the ears treated with calcium channel blockers did as well although to a lesser degree. Under light microscopy, the lamina propria of both tympanic membranes and middle ear mucosae of the control group exhibited thicker (P < .1 and P < .05, respectively) and larger (P < .01 and P < .01, respectively) sclerotic tissue in comparison with the treatment group. CONCLUSION: The results suggest that calcium channel blockers had an influence in the prevention of tympanosclerosis.