World Eye and Vision Congress

Biography

Biography: Mohammed E Mahdy

Abstract

Introduction: Idiopathic Intracranial Hypertension (IIH), also referred to as benign intracranial hypertension, is a disorder generally affecting overweight women of childbearing age. Idiopathic intracranial hypertension has often been considered a diagnosis of exclusion, especially if no cranial neuropathies or papilloedema have been detected. Measurement of the Optic Nerve Sheath Diameter (ONSD) using CT scan can provide a solution for this situation, as it has been used as a non-invasive method of ICP monitoring since the mid-1990s. Another rapid non-invasive method for evaluation of patients with IIH is Optical Coherence Tomography (OCT). Spectral-domain OCT provides reliable thickness and volume measurements of the optic nerve head and retina and can reliably demonstrate structural changes due to papilloedema. This study included 40 patients (aged ≥18 years) presented with headache and fulfilled modified Dandy criteria for IIH.

Method: We collected and analyzed data on the following variables: ONSD in the middle third of the intraorbital path (the point where the ophthalmic artery crosses the optic nerve served as an anatomical landmark); Our patients underwent spectral domain OCT (SD-OCT) scanning dual beam Spectralis laser tracking tomography Spectralis®, using a commercially available device (3D OCT-1000; Topcon Corp., Tokyo, Japan). The scanning protocol involved the acquisition of a 6×6 mm cube scan of the Optic Nerve Head (ONH) and macula with a scan density of 512×128 pixels.

Results: Our study included 40 female patients with clinico-radiological diagnosis of IIH with their age range from 22 to 42 years, their main complaints were visual complaints as blurred vision and transient visual obscurations in 16 patients (40%), and headache in 15 patients (37.5%), while 9 patients (22.5%) had both complaints (table 1). None of our patients developed side effects or allergic reaction with the used contrast agent in orbital CT with contrast. The ONSD was nearly in the same range in both eyes (4-10 mm for right and 4-11 mm for left) when measured by CT with contrast at the crossing point of ophthalmic artery (table2). More than 82% (33) of patients diagnosed by OCT to have papilloedema while in 17% (7) of patients not (table 3). There was a statistical significant relation between the ONSD by OCT in both right and left sides with the diagnosis of IIH (P =0.003 for right, P= 0.001 for left) while there was no significant relation between PTC and patient's age (P= 0.921) (table 4). The estimated statistical cutoff value of ONSD was 5.5 mm with sensitivity of 84.4% and a specificity to diagnose optic nerve thickening by 100% in the left side and 85.7% in the right side (table 5, 6)

Conclusion: The addition of OCT to ONSD by CT+C can increase its diagnostic ability for the cases with IIH, which may reduce the need for invasive diagnostic techniques like LP.