Macular photoreceptor organization

Modular substructuring — a consistent feature along all foveal cone elements


A precondition for maximum acuity and other optimizations of human and primate photopic visual function is the high density of the retinal foveolar cones. Spatial packing is near optimum in the all-cone foveal center but always deviations from ideal hexagonal order remain. Pattern analysis has allowed to demonstrate the presence of serially arranged lattice defects separating crystalline patches sharing similar axial orientation [18]. The present study demonstrates similar patchwork-like organizations in the initial portion of cone axons. It is proposed that these patterns are correlated with the batch-wise descendence and sequential stacking of cone cell bodies during mosaic condensations. The multitiered relocation of the primarily monolayered macular sensory epithelium compensates the diameter difference between somata and slender inner segments. Induced by the arrangement of somata this modular organization is projected upon the two dimensional aspects on both sides of the ONL: distally it appears as the inner/outer segment patches and proximally it leads to the bundling of cone axons below the nuclear layer. Thus discontinuities are an inherent element of fovea) microarchitecture and may be sites of increased vulnerability to mechanical/osmotic stress and retinoschisis.


Outer Nuclear Layer Human Retina Modular Organization External Limit Membrane Axon Bundle 


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  1. 1.
    Ahnelt PK (1998) The photoreceptor mosaic. Eye 12: 531–40PubMedCrossRefGoogle Scholar
  2. 2.
    Ahnelt PK, Pflug R (1986) Telodendrial contacts between foveolar cone pedicles in the human retina. Experientia 42: 298–300PubMedCrossRefGoogle Scholar
  3. 3.
    Ahnelt PK, Kolb H (2000) The mammalian photoreceptor mosaic-adaptive design. Prog Retin Eye Res 19: 711–77PubMedCrossRefGoogle Scholar
  4. 4.
    Ahnelt PK, Kolb H, Pflug R (1987) Identification of a subtype of cone photoreceptor, likely to be blue sensitive, in the human retina. J Comp Neurol 255: 18–34PubMedCrossRefGoogle Scholar
  5. 5.
    Curcio CA, Sloan KR (1992) Packing geometry of human cone photoreceptors: variation with eccentricity and evidence for local anisotropy. Vis Neurosci 9: 169–80PubMedCrossRefGoogle Scholar
  6. 6.
    Curcio CA, Sloan KR, Kalina RE, Hendrickson AE (1990) Human photoreceptor topography. J Comp Neurol 292: 497–523PubMedCrossRefGoogle Scholar
  7. 7.
    Fine BS, Yanoff (1988) Ocular histology, 2nd edn, Harper & Row, New YorkGoogle Scholar
  8. 8.
    Hendrickson AE, Yuodelis C (1984) The morphological development of the human fovea. Ophthalmology 91: 603–12PubMedGoogle Scholar
  9. 9.
    Hirsch J, Curcio CA (1989) The spatial resolution capacity of human foveal retina. Vision Res 29: 1095–101PubMedCrossRefGoogle Scholar
  10. 10.
    Hoang QV, Linsenmeier RA, Chung CK, Curcio CA (2002) Photoreceptor inner segments in monkey and human retina: mitochondrial density, optics, and regional variation. Vis Neurosci 19: 395–407PubMedCrossRefGoogle Scholar
  11. 11.
    Krebs IP, Krebs W (1989) Discontinuities of the external limiting membrane in the fovea centralis of the primate retina. Exp Eye Res 48: 295–301PubMedCrossRefGoogle Scholar
  12. 12.
    Miller WH, Bernard GD (1983) Averaging over the foveal receptor aperture curtails aliasing. Vision Res 23: 1365–9PubMedCrossRefGoogle Scholar
  13. 13.
    Murillo Lopez F, Fukuhara J, Wisnicki HJ, Guyton DL (1994) Origin of the fovea) granular pattern in entoptic viewing. Invest Ophthalmol Vis Sci 35: 3319–24PubMedGoogle Scholar
  14. 14.
    Perry VH, Cowey A (1985) The ganglion cell and cone distributions in the monkey’s retina: implications for central magnification factors. Vision Res 25: 1795–810PubMedCrossRefGoogle Scholar
  15. 15.
    Pöppe CH (1989) Graphische Darstellung komplex-analytischer Funktionen. Spektrum Wiss 8: 8–13Google Scholar
  16. 16.
    Provis JM, Diaz CM, Dreher B (1998) Ontogeny of the primate fovea: a central issue in retinal development. Prog Neurobiol 54: 549–80PubMedCrossRefGoogle Scholar
  17. 17.
    Provis JM, van Driel D, Billson FA, Russell P (1985) Development of the human retina: patterns of cell distribution and redistribution in the ganglion cell layer. J Comp Neurol 233: 429–51PubMedCrossRefGoogle Scholar
  18. 18.
    Pum D, Ahnelt PK, Grasl M (1990) Iso-orientation areas in the foveal cone mosaic. Vis Neurosci 5: 511–23PubMedCrossRefGoogle Scholar
  19. 19.
    Schein SJ (1988) Anatomy of macaque fovea and spatial densities of neurons in foveal representation. J Comp Neurol 269: 479–505PubMedCrossRefGoogle Scholar
  20. 20.
    Sekiguchi N, Williams DR, Packer 0 (1991) Nonlinear distortion of gratings at the foveal resolution limit. Vision Res 31: 815–31Google Scholar
  21. 21.
    Sjöstrand J, Popovic Z, Conradi N, Marshall J (1999) Morphometric study of the displacement of retinal ganglion cells subserving cones within the human fovea. Graefes Arch Clin Exp Ophthalmol 237: 1014–23PubMedCrossRefGoogle Scholar
  22. 22.
    Williams DR (1985) Aliasing in human foveal vision. Vision Res 25: 195–205PubMedCrossRefGoogle Scholar
  23. 23.
    Williams DR (1988) Topography of the foveal cone mosaic in the living human eye [see comments]. Vision Res 28: 433–54PubMedCrossRefGoogle Scholar
  24. 24.
    Yellott JI, Jr (1983) Spectral consequences of photoreceptor sampling in the rhesus retina. Science 221: 382–5PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag/Wien 2004

Authors and Affiliations

  1. 1.Department of PhysiologyVienna Medical UniversityViennaAustria

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