Transorbital sonographic evaluation of normal optic nerve sheath diameter in healthy volunteers in Bangladesh.

INTRODUCTION: Measurement of optic nerve sheath diameter (ONSD) by ultrasound is increasingly used as a marker to detect raised intracranial pressure (ICP). ONSD varies with age and there is no clear consensus between studies for an upper limit of normal. Knowledge of normal ONSD in a healthy population is essential to interpret this measurement. METHODS: In a prospective observational study, ONSD was measured using a 15 MHz ultrasound probe in healthy volunteers in Chittagong, Bangladesh. The aims were to determine the normal range of ONSD in healthy Bangladeshi adults and children, compare measurements in males and females, horizontal and vertical beam orientations and left and right eyes in the same individual and to determine whether ONSD varies with head circumference independent of age. RESULTS: 136 subjects were enrolled, 12.5% of whom were age 16 or under. Median ONSD was 4.41 mm with 95% of subjects in the range 4.25-4.75 mm. ONSD was bimodally distributed. There was no relationship between ONSD and age (≥4 years), gender, head circumference, and no difference in left vs right eye or horizontal vs vertical beam. CONCLUSIONS: Ultrasonographic ONSD in Bangladeshi healthy volunteers has a narrow bimodal distribution independent of age (≥4 years), gender and head circumference. ONSD >4.75 mm in this population should be considered abnormal.

Audit of otitis externa referrals and management in a tertiary care setting.

OBJECTIVE: To assess the initial management of acute otitis externa (AOE) in primary care and the appropriateness of referrals to the otolaryngology department. STUDY DESIGN: Prospective audit. SETTING: Tertiary referral centre. METHODS: Data were collected from 100 consecutive patients referred by their general practitioners (GPs) during a 6-week period to our otolaryngology department. A working diagnosis of AOE was made either by the GP or in the otolaryngology urgent referral clinic. MAIN OUTCOME MEASURES: The referring diagnosis, time lag before referral, investigations prior to initial management, and any patient advice given. RESULTS: Of 100 patients referred, 98% had AOE, 60% were referred with a correct diagnosis, and 30% referred had no diagnosis. Of all the referrals, nearly half were prescribed oral antibiotics, with 11% being treated with oral antibiotics exclusively; 59% had topical antimicrobials prescribed; and 24% were given no treatment. Seventy-three percent of patients were referred within 2 weeks following initial presentation to primary care, and the majority received no advice regarding their condition and/or precautions. CONCLUSIONS: AOE is one of the most common adult otologic conditions presenting to the GP. Based on our results, most patients presenting with this common problem are not receiving optimal initial management or advice prior to otolaryngology referral. Greater awareness of the correct management of AOE in the community is needed. An overview of AOE and its management is provided.