Micropsia and visual acuity in macular edema. A study of the neuro-retinal basis of visual acuity.
Relative micropsia was measured by a matching technique in patients with unilateral, benign, macular edema. Quantitative assessment of foveolar micropsia to be a sensitive indicator of receptor displacement in this disorder, and may be a useful tool both for diagnosing and for monitoring macular edema. Parallel measurements of grating acuity showed a close proportionality between acuity and micropsia parameters. This result validates a new quantitative theory for the neuro-retinal basis of visual acuity. The theory allows prediction of the proportion of working visual neurons in patients with impaired acuity due to diseases that produce a diffuse loss, or disconnection, of macular cones. Our results indicate that so-called normal visual acuity (1.0 or 20/20) requires no more than 44% of the normal quantity of fovelar, neuro-retinal channels.
D006801:Humans; D012164:Retinal Diseases / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D014786:Vision Disorders / Q000209:etiology*; D014792:Visual Acuity