Micropsia and visual acuity in macular edema

A study of the neuro-retinal basis of visual acuity
  • Lars Frisén
  • Marianne Frisén


Relative micropsia was measured by a matching technique in patients with unilateral, benign, macular edema. Quantitative assessment of foveolar micropsia appeared 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 foveolar, neuro-retinal channels.


Public Health Visual Acuity Quantitative Assessment Normal Quantity Macular Edema 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Amsler, M.: Earliest symptoms of diseases of the macula. Br. J. Ophthalmol. 37, 521–537 (1953)PubMedGoogle Scholar
  2. 2.
    Fankhauser, F., Enoch, J., Cibis, P.: Receptor orientation in retinal pathology. Am. J. Ophthalmol. 52, 767–783 (1961)PubMedGoogle Scholar
  3. 3.
    Finney, D.J.: Probit analysis, ed. 3. Cambridge: University of Cambridge Press 1971Google Scholar
  4. 4.
    French, A.S., Snyder, A.W., Stavenga, D.G.: Image degradation by an irregular retinal mosaic. Biol. Cybern. 27, 229–233 (1971)Google Scholar
  5. 5.
    Frisén, L., Frisén, M.: A simple relationship between the probability distribution of visual acuity and the density of retinal output channels. Acta Ophthalmol. 54, 437–444 (1976)Google Scholar
  6. 6.
    Frisén, L., Glansholm, A.: Optical and neural resolution in peripheral vision. Invest. Ophthalmol. 14, 528–536 (1975)PubMedGoogle Scholar
  7. 7.
    Helmholtz, H.: Handbuch der physiologischen Optik. p. 215 Leipzig: Leopold Voss 1867Google Scholar
  8. 8.
    Leber, T.: Die Krankheiten der Netzhaut. In: Handbuch der gesamten Augenheilkunde, ed. 2, T. Saemisch und A. Elschnig, eds., Vol. 7:II, pp. 705–707. Leipzig: W. Engelmann (1915)Google Scholar
  9. 9.
    Lythgoe, R.J.: The measurement of visual acuity. Med. Res. Counc. (GB) Spec. Rep. Ser. 173, 1–85 (1932)Google Scholar
  10. 10.
    Missotten, L.: Estimation of the ratio of cones to neurons in the fovea of the human retina. Invest. Ophthalmol. 13, 1045–1049 (1974)PubMedGoogle Scholar
  11. 11.
    Pirenne, M.H.: Vision and the eye, ed. 2, pp. 141–152 London: Science Paperbacks 1967Google Scholar
  12. 12.
    Polyak, S.L.: The retina. Chicago: University of Chicago Press, 1941Google Scholar
  13. 13.
    Smith, V.C., Pokorny, J., Diddie, K.R.: Color matching and Stiles-Crawford effect in central serous choroidopathy. Mod. Probl. Ophthalmol. 19, 284–295 (1978)PubMedGoogle Scholar
  14. 14.
    Stiles, W.S., Crawford, B.H.: The luminous efficiency of rays entering the eye pupil at different points. Proc. R. Soc. Lond. [Biol.] 112, 428–450 (1933)Google Scholar
  15. 15.
    Westheimer, G.: Visual acuity. Ann. Rev. Psychol. 16, 359–380 (1965)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 1979

Authors and Affiliations

  • Lars Frisén
    • 1
  • Marianne Frisén
    • 1
  1. 1.The Departments of Ophthalmology and StatisticsUniversity of GöteborgSweden

Personalised recommendations