New objective visual field test measures pupillary response to detect AMD.
A newly available eye test can help warn of the presence of AMD in its earliest stages. The test uses multifocal pupillographic objective perimetry (mfPOP)—a non-contact, bilateral, visual field test that measures pupillary responses to multifocal visual stimuli—as a means to diagnose sight-threatening diseases.

A group of researchers in Australia used the True Field Analyzer (Seeing Machines), a device that takes advantage of mfPOP, and found significant differences in the pupil responses of 19 patients with early AMD vs. 29 age-matched control subjects.

The device examined the subjects’ pupil responses to various images displayed on LCD screens. A luminance-balanced stimulusensemble and two unbalancedstimulus variants were conductedon 44 locations on each patient’s visual field, and the responseswere then recorded by two videocameras that use infrared lighting. The researchers found that the pupils of patients with early AMD displayed significant abnormalities in their responses to the stimuli vs. the control subjects. Subjects with early AMD showed significant differences in both mean constriction amplitudes and delays when compared to the control subjects. Patients with early AMD are still capable of seeing objects in fine detail, making the early signs of the disease difficult to detect. Most tests only examine the central vision, but mfPOP examines other areas of the retina affected by drusen buildup, the researchers concluded.

Sabeti F, James AC, Essex RW, Maddess T. Multifocal pupillographyidentifi es retinal dysfunction in early age-related macular degeneration. Graefes Arch Clin Exp Ophthalmol.2013 Jul;251(7):1707-16.