The Effect of Allantoin on Chronic Perforation of Rat Tympanic Membrane.

OBJECTIVES: This study aimed to investigate the effectiveness of topical allantoin application on wound healing in a rat chronic tympanic membrane perforation (TMP) model. METHODS: A chronic TMP model was established with 25 healthy, female, 6-month-old, Sprague Dawley rats with chemical damage (trichloroacetic acid 50%). The rats were randomly assigned into 3 groups as follows: Group 1 (10 rats, 20 ears) was administered intratympanic (IT) 20 µL/day 0.57% allantoin solution 7 times, every other day; Group 2 (5 rats, 10 ears) received no substance; Group 3 (10 rats, 20 ears) received IT 20 µl/day distilled water 7 times, every other day. After tympanic membrane (TM) examination with an otoendoscope, histopathological examination of the TM was performed to evaluate neutrophil activity, chronicity, histiocytes, keratin accumulation, subepithelial edema, congestion, fibroblast proliferation, neovascularization, and tympanic membrane thickness. RESULTS: Two TM perforations, 1 in Group 1 and 1 in Group 3, were not healed whereas TM perforations in 48 ears demonstrated closure at the end of the study. According to the histopathological examination, neutrophil activity and fibroblast proliferation were significantly higher in Group 1. There was no significant difference between the groups in terms of other histopathological parameters. CONCLUSION: To the best of our knowledge, this is the first study investigating the effect of allantoin in an experimental chronic TMP model. According to the histopathological findings, allantoin may have positive effects on the wound healing process of chronic TMP.

Does blindness affect ocular vestibular evoked myogenic potentials?

OBJECTIVE: The aim of the present study was to investigate the influence of blindness on ocular vestibular evoked myogenic potentials (oVEMP) responses. METHODS: Thirty-one subjects with unilateral blindness (UB group) and 25 age and sex-matched healthy subjects (control group) were recruited for the present study. The oVEMP responses including latency, amplitude and amplitude asymmetry ratio (AR) were measured and compared between the blind side, the contralateral eye of the UB group and the control subjects. RESULTS: Ocular VEMP recordings were obtained from 29 of 31 patients (93.5%) for the blind side of the UB group. There was no significant difference in terms of latency, amplitude and AR value between the blind side and the contralateral eye of the UB group and the control subjects. CONCLUSION: Clear oVEMP recordings can be elicited as long as the eyeball and extraocular muscles are preserved in a blind eye.