A recent study found that testing a patient’s sensitivity to radial deformation may help with AMD staging. The study aimed to distinguish between two levels of intermediate AMD: eyes with large macular drusen with and without retinal pigment abnormalities. Abnormal pigmentation in the presence of large drusen is a prominent risk factor for advanced AMD development, the study authors noted in their paper.

In the ongoing longitudinal study, the researchers tested 39 eyes of 39 individuals who had the same form of intermediate AMD in both eyes. Each individual was tested monocularly for photopic optotype contrast sensitivity, discrimination of desaturated colors and sensitivity to radial deformation, i.e., shape discrimination hyperacuity.

They found that in eyes with large drusen and pigment changes, sensitivity to radial deformation was significantly reduced compared with eyes with large drusen and normal retinal pigmentation. Based off this finding, the study authors concluded that shape discrimination hyperacuity is a potential measure for distinguishing between disease severity levels and aiding in the prediction of progression to advanced disease. They also noted that this measure has “fair to good” discrimination of eyes with large drusen and pigment from eyes with large drusen only.