Peripapillary Choroidal Vascularity Index for Differentiating Papilledema from Pseudopapilledema: A Deep...

Area of Science:

• Ophthalmology
• Neuro-ophthalmology
• Medical Imaging

Background:

• Idiopathic intracranial hypertension (IIH) and optic disc drusen (ODD) can cause papilledema and pseudopapilledema, respectively, requiring accurate differentiation.
• Peripapillary choroidal vascularity index (PPCVI) is a quantitative measure of choroidal vasculature.

Purpose of the Study:

• To compare PPCVI in eyes with papilledema secondary to IIH versus pseudopapilledema due to ODD.
• To evaluate PPCVI changes in IIH patients before and after papilledema resolution using a deep learning algorithm.

Main Methods:

• Retrospective observational cohort study including 30 eyes with IIH, 30 eyes with ODD, and 78 healthy controls.
• Optical coherence tomography (OCT) peripapillary scans analyzed with a deep learning ResUNet model for choroidal segmentation.
• Quantification of PPCVI and statistical comparison between groups and longitudinally in IIH patients.

Main Results:

• No significant differences in age, sex, visual acuity, or intraocular pressure among groups.
• Mean PPCVI was significantly lower in the papilledema (IIH) group compared to pseudopapilledema (ODD) and control groups (31.7% vs. 39.0% and 40.7%, respectively; P < 0.001).
• Following papilledema resolution in IIH patients, PPCVI increased significantly (34.8% vs. 31.7%; P = 0.033) but remained lower than controls.

Conclusions:

• Reduced PPCVI may serve as a biomarker to differentiate papilledema from pseudopapilledema.
• The increase in PPCVI after resolution of papilledema indicates its potential utility in monitoring IIH disease activity.