Purpose : Patients with age-related macular degeneration (AMD) report considerable difficulty with face perception which has been linked with reduced quality of life. It has been suggested that different aspects of faces are particularly relevant for different tasks: external face features (e.g. head-shape and hairline) for unfamiliar face discrimination, versus internal features (e.g. eyes, mouth) for familiar faces and facial expressions. We aimed to employ a new clinical test to quantify the impact of AMD on different aspects of face discrimination.Methods : Participants were 20 patients with non-exudative AMD (LogMAR VA = 0.14 to 0.62), 20 patients with exudative AMD (0.10 to 0.60) and 20 age-matched controls (-0.18 to +0.06). Face discrimination thresholds, the minimum difference required between faces for reliable discrimination, were measured with the Caledonian face test. This test uses an adaptive procedure embedded within a memory-free, odd-one-out paradigm. Thresholds were measured separately for full-faces, external features (head-shape and hairline) and internal features (eyes, eyebrows, mouth and nose).Results : Discrimination thresholds for full-faces were, on average, 1.76 and 1.73 times poorer, relative to controls, in participants with non-exudative and exudative AMD respectively (both p<0.001). Multiple regression identified distance VA and contrast sensitivity as significant predictors of full-face discrimination thresholds (R2=0.66). The ability to discriminate between full faces reduced by a factor of 1.19 per 0.1 logMAR reduction in VA. However, AMD did not affect all aspects equally: sensitivity to the internal features was substantially more impaired (2.33) than that to the external features (1.56 times poorer; p<0.001).Conclusions : AMD significantly reduces sensitivity to full-faces and their component features. In the patients that we tested, non-exudative and exudative AMD impaired sensitivity to comparable extents. VA is significantly associated with the ability to discriminate between full faces. Importantly, AMD does not impair discrimination of all face features equally; sensitivity to the internal features is disproportionately impaired. Our results suggest that patients with AMD may experience particular difficulty with tasks which are reliant upon information from the internal features, such as familiar face recognition and interpreting facial expressions.This is a 2020 ARVO Annual Meeting abstract.
|Journal||Investigative Ophthalmology & Visual Science|
|Publication status||Published - Jun 2020|
- face perception
- age-related macular degeneration
- clinical tests
- vision science