True swelling of the optic nerve head (papilledema) is an urgent, life-threatening condition. Pseudopapilledema, on the other hand, is a mostly benign buildup of optic nerve drusen. Telling them apart can be tricky, and doctors rarely have the luxury of time to do so. Papilledema can indicate an underlying brain tumor, obstructive hydrocephalus or meningitis.

Over the years, doctors have hunted for small distinctions—such as the presence of Paton’s Lines, flame-shaped hemorrhages or cotton wool spots, but while these aren’t present in pseudopapilledema, they’re not 100% guaranteed to be present in papilledema either.¹

According to new research out of Iran, optical coherence tomography angiography (OCT-A) technology may hold the key to distinguishing the conditions.² The study looked at the OCT-A images of 41 eyes (from 21 subjects) with papilledema, 27 (15 subjects) with pseudopapilledema and an additional 44 eyes of healthy subjects.

The authors employed several features of the imaging tech, including peripapillary total vasculature maps obtained with commercial vessel density mapping, major vessel removal using customized image analysis software (to measure whole image capillary density) and peripapillary capillary density. The subjects’ peripapillary retinal nerve fiber layer (RNFL) was recorded and the researchers were able to distinguish true from pseudo swelling using this measurement. The average RNFL thicknesses were substantially greater in papilledema eyes. Macular ganglion cell complex readings were not different among the groups.