Methods: There were 20 healthy participants with normal ears, and all gave an informed consent. After an otoscopy, a baseline pure tone audiogram (PTA) was conducted. If the PTA of the participant was normal, aqueous cream was applied with a syringe via an 18 G cannula, from the tympanic membrane up to the isthmus which corresponds to the bony ear canal. A second PTA was conducted, and subsequently the cream was removed via suction under microscope guidance. The procedure was then repeated with the cream applied from the isthmus to the aperture of the external ear canal using the same cannula followed by a PTA and removal of cream under microscope.
Results: The mean threshold difference of occlusion at both portions of the ear canal were compared and analyzed. The mean threshold difference of hearing loss upon occlusion at the cartilaginous EAC was 37.5 to 48 dB. The mean threshold difference of hearing loss upon occlusion at the bony EAC was less, with a range of 21 to 24.95dB. There was a statistical difference (p<0.05) in the hearing loss between the blockage of the cartilaginous canal versus the blockage of the bony canal with a maximum difference at 2kHz.
Conclusion: Cartilaginous block of the external ear canal causes more hearing loss than block of the bony ear canal. This correlates with the concept and properties of sound waves, resonance and impedance.
METHOD: A prospective analysis was conducted on 173 patients (346 ears) with cleft lip and palate (CL/P) who presented to the combined cleft clinic at University Malaya Medical Centre (UMMC) over 12 months. The patients' hearing status was determined using otoacoustic emission (OAE), pure tone audiometry (PTA) and auditory brainstem response (ABR). These results were analysed against several parameters, which included age, gender, race, types of cleft pathology, impact and timing of repair surgery.
RESULTS: The patients' age ranged from 1-26 years old. They comprised 30% with unilateral cleft lip and palate (UCLP), 28% with bilateral cleft lip and palate (BCLP), 28% with isolated cleft palate (ICP) and 14% with isolated cleft lip (ICL). Majority of the patients (68.2%) had normal otoscopic findings. Out of the 346 ears, 241 ears (70%) ears had passed the hearing tests. There was no significant relationship between patients' gender and ethnicity with their hearing status. The types of cleft pathology significantly influenced the outcome of PTA and ABR screening results (p
METHODS: A case-control study was carried out among patients with CSOM (cases) and controls were those with no ear pathology. The presence of CSOM was made through a medical history and otoscopic examination. Allergen testing was done by the skin prick test.
RESULTS: In all 124 subjects were recruited in this study with equal number of the cases and controls. The commonest positive reaction in the skin prick test in both groups was to house dust mites. Among CSOM cases, half (50%) of them had an allergy to Blomia tropicalis and 48.4% to Dermatophagoides while in the control group, 27.4% to Dermatophagoides and 25.8% to B. tropicalis. There were significant associations between CSOM and allergy to B. tropicalis (p=0.005), Dermatophagoides (p=0.016) and Felis domesticus (p=0.040). The prevalence of allergy at 95% confidence interval (95%CI) in CSOM and control groups were demonstrated as 59.7% (95%CI: 47.5, 71.9) and 30.6 % (95%CI: 19.1, 42.1) respectively. There was a significant association between allergy and CSOM (p=0.001).
CONCLUSION: Indoor allergens are the most prevalent in our environment and therefore good control may difficult to achieve. The hypersensitivity states of the subject are likely to have a role in the pathogenesis of CSOM especially in the tropical countries where allergy occurs perennially.