OCT for optic disc evaluation in idiopathic intracranial hypertension

Optical coherence tomography (OCT) enables quantification of retinal layer thicknesses. Studies evaluating the ability of OCT to identify and quantify papilledema are few. Therefore, the aim was to evaluate the applicability of peripapillary OCT evaluation in an unselected, consecutive series of patients with confirmed idiopathic intracranial hypertension (IIH).

A case-control study of 20 patients with newly diagnosed IIH and 20 healthy subjects. Subjects were evaluated by means of direct ophthalmoscopy, masked evaluations of fundus photography, peripapillary retinal nerve fiber layer thickness (RNFLT), and peripapillary average retinal thickness (PART) measurements (Stratus OCT-3, fast RNFL 3.4 protocol).

OCT evaluation of PART revealed the highest number of patients (n = 20) with optic disc abnormalities in either eye (90%), compared with 85%, 80% and 70% for RNFLT measurements, direct ophthalmoscopy, and fundus photography respectively. There was a linear association between means and differences of OCT data (RNFLT, PART) with a slope of 0.54 (SE 0.025), p < 0.001.

Peripapillary OCT is a promising objective examination modality for optic disc evaluation in IIH, and may improve the identification of subtle disc swellings. Underestimation of RNFLT for increasing severities of papilledemas is suspected, making PART a more reliable parameter compared to RNFLT. Future larger validation studies are needed.