Why do AMD patients have trouble recognizing and identifying faces?

The January issue of Optometry and Vision Science includes the results of a study which compared the ability of AMD patients and normal healthy control subjects to recognize the internal features of the famous painting "Mona Lisa". The study reveals that the struggle to recognize familiar faces is a result of abnormal eye movement patterns and fixations related to AMD. AMD causes the retina to become severely damaged, which results in impairment of the person's vision in the center of the visual field, which results in images being blurry. During the study, researchers examined and analyzed the interior of the eyes of patients with AMD using optical coherence tomography/scanning laser opthalmoscopy (OCT-SLO). This technology allowed the researchers to make "movies" of the interior of the eye which they then studied to see the movement patterns and fixation points as the patients looked at the painting of Mona Lisa. What researchers discovered is that AMD patients made more frequent eye movements compared to the healthy vision study subjects. This led researchers to believe that the problem that AMD patients have with recognizing faces is related to this abnormal eye movement and not just to their overall vision loss. The researchers are hopeful that eye movement control training and training of allocation of attention could improve face perception and eye scanning behavior in AMD patients.*