Is there a common factor for vision?

Aims/Purpose: Eye diseases are implicitly assumed to affect vision generally. However, only visual acuity and contrast sensitivity are usually measured to determine perceptual deficits. What about orientation and motion perception?

Methods: To address these questions, we first conducted 19 visual tests, including visual acuity (determined by Landolt Cs and verniers), various motion tests, etc., in a large sample of 104 young and 92 older healthy participants. Second, we investigated 50 patients with age‐related macular degeneration (AMD) and 49 age matched controls, administering a battery of six perceptual tests. In addition, OCT images of the retina, choroid, and optic nerve were recorded.

Results: Surprisingly, in the young and old healthy population, the tests correlated only weakly, and the factor structure was rather flat. Hence, single eye tests tell very little about vision in the healthy population. What about disease? AMD patients were impaired in all perceptual tests compared to age matched controls, except for motion perception. Detailed OCT analysis and retinal layer segmentation showed that the thickness of the retinal pigment epithelium drusen complex (RPEDC) determines deficits most strongly ( r =0.40). We found moderate correlations between the tests, which we attribute to the thickness of the RPEDC layer. However, motion perception was independent of RPEDC thickness, suggesting that AMD does not affect all visual abilities equally.

Conclusions: Our results show the need to investigate healthy and clinical vision with batteries of tests rather than with a single contrast or spatial acuity measure.