Abstract
Purpose: :
Deficit in face perception have been reported in patients with age-related macular degeneration (Alexander et al., 1988; Bullimore et al., 1991; Tejeria et al., 2002). These losses were related to text reading acuity, which may reflect the abnormal eye movement patterns observed in patients with AMD. Other groups of subjects have difficulties with face perception. Older subjects do not identify emotion from faces as well as younger subjects and people with autism, social phobias, and schizophrenics also have face recognition deficits. There are reports that face processing deficits in these patients, who have no retinal disease, are due to abnormal scanning patterns. Specifically, they fixate on external rather than internal facial features. The question addressed by the current work was whether the face processing deficits in AMD patients are related to altered abnormal scanning patterns.
Methods: :
Patients with macular degeneration were recruited who had visual acuities < 20/200. Locus of fixation and microperimetry were recorded using the OPKO OCT/SLO. Images of familiar faces were presented on the OLED of the machine and the subjects were instructed to identify the face. Eye scanning behavior was recorded using the SLO. The position of a patient’s fixation point (fovea or PRL) was recorded on each frame. The locus of these positions was tabulated into fixation on the eyes, nose, and mouth, or on external features.
Results: :
Normally sighted subjects predominately fixated on the internal features of the face (53% on the eyes, 37% on the nose, 5% on the mouth and 5% on the external features). Patients with AMD and good central vision had similar scanning patterns as the control subjects. For the AMD patients with PRLs, fixations were 8% on the eyes, 17% on the nose, 12% on the mouth, and 63% on the external features.
Conclusions: :
The results suggest that the deficits in face processing observed in patients with AMD may be related to abnormal patterns of scanning.
Keywords: age-related macular degeneration • low vision • eye movements