High Frequency Ultrasound In The Measurement Of Disc Oedema In Patients With Idiopathic Intracranial Hypertension Before And After Weight Loss

1. Peter Good
2. Michael Burdon

Birmingham and Midland Eye Centre Birmingham UK

Purpose: Idiopathic Intracranial Hypertension (IIH) is characterized ophthalmologically by papilloedema. The elevation of the optic discs is related to the severity of the disease. Accurate measurement of optic disc elevation depends on imaging (normally OCT) This study assesses the use of high frequency posterior segment Ultrasound (USG) in disc elevation measurements in papilloedema, as a novel imaging technique.

Methods: 26 Patients (all female) with IIH underwent High frequency Ultrasound using a 20 MHz posterior segment probe (Aviso Quantel Medical Clermond Ferrand France). Measurements of disc elevation and cross sectional retrobulbar optic nerve diameter were made before and after 12 months of clinically monitored diet induced weight loss.

Results: 24/26 Patients achieved weight loss after the completion of the diet with a mean weight loss of 9.86 Kg. Optic disc elevation reduced from a mean elevation of 1.44 mm (Sd 0.07 mm) to 1.02 mm (Sd 0.06 mm) on completion of the study. Mean optic nerve diameter reduced from 4.83 mm (Sd 0.32 mm) to 3.44 mm (Sd 0.33 mm) over the same time period.

Conclusions: Clinically controlled weight loss is an effective method of reducing papilloedema in IIH.20 MHz USG is an accurate means of quantifying changes in optic disc morphology and optic nerve diameter.