Objective:

 Describe the utility of virtual perimetry in workup  of patients with functional visual loss (FVL) .

Background:

Functional vision loss can be difficult to prove especially when deficits are seen on automated perimetry. Virtual reality (VR) perimetry has emerged as a promising tool for assessing visual function in individuals with FVL.

Design/Methods:

 Retrospective review of 5 patients ages 19-60 years presenting with visual defects on automated perimetry due to functional visual loss.  The patients presented with varied visual symptoms including abnormal automated perimetry in contrast to intact confrontational perimetry and normal structural exam. Virtual perimetry (neos, machineMD) was performed and compared to automated perimetry.

Results:

While standard automated perimetry revealed  varied defects,  VR perimetry documented largely normal visual fields. 2 patients had monocular deficits on perimetry and normal virtual perimetry; 2 patients with monocular deficit on automated perimetry showed a homonymous pattern on virtual;1 patients with right homonymous defects on automated perimetry had normal virtual perimetry.

Conclusions:

VR-based perimetry provides a novel tool for assessing visual function  and may be a valuable adjunct in evaluating patients with suspected functional visual loss. The usefulness of virtual perimetry in functional patients may be related to a binocular paradigm with monocular data acquisition.