Descemet's membrane

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Descemet's membrane
Corneal corpuscles appearing fusiform in section
  • Lamellae, the fibers of which are cut longitudinally
  • Transition to the sclera, with more distinct fibrillation, and surmounted by a thicker epithelium
  • Small blood vessels cut across near the margin of the cornea
    • Details
    PronunciationEnglish: /ˈdɛsəmeɪ/
    LocationCornea of eye
    Identifiers
    Latinl. limitans posterior corneae
    MeSHD003886
    TA98A15.2.02.021
    FMA58309
    Anatomical terms of microanatomy]

    Descemet's membrane (or the Descemet membrane) is the basement membrane that lies between the corneal proper substance, also called stroma, and the endothelial layer of the cornea. It is composed of different kinds of collagen (Type IV and VIII)[1] than the stroma. The endothelial layer is located at the posterior of the cornea. Descemet's membrane, as the basement membrane for the endothelial layer, is secreted by the single layer of squamous epithelial cells that compose the endothelial layer of the cornea.

    Structure

    Its thickness ranges from 3 μm at birth to 8–10 μm in adults.[2]

    The corneal endothelium is a single layer of squamous cells covering the surface of the cornea that faces the

    anterior chamber
    .

    Clinical significance

    Copper disposition on corneal Descemet's membrane

    Significant damage to the membrane may require a corneal transplant. Damage caused by the hereditary condition known as

    Fuchs dystrophy (q.v.)—where Descemet's membrane progressively fails and the cornea thickens and clouds because the exchange of nutrients/fluids between the cornea and the rest of the eye is interrupted—can be reversed by surgery. The surgeon can scrape away the damaged Descemet membrane and insert/transplant a new membrane harvested from the eye of a donor.[3] In the process most of the squamous cells of the donor membrane survive to dramatically and emphatically reverse the corneal deterioration (see DMEK surgery
    ).

    Descemet's membrane is also a site of copper deposition in patients with Wilson's disease or other liver diseases, leading to formation of Kayser–Fleischer rings.

    History

    It is also known as the posterior limiting elastic lamina, lamina elastica posterior, and membrane of Demours. It was named after French physician Jean Descemet (1732–1810).

    See also

    References

    1. ^ "Tissue Distribution of Type VIII Collagen in Human Adult and Fetal Eyes" (PDF). Investigative Ophthalmology and Visual Science. 1991-08-01. Retrieved 2014-08-17.
    2. ^ Johnson DH, Bourne WM, Campbell RJ: The ultrastructure of Descemet's membrane. I. Changes with age in normal cornea. Arch Ophthalmol 100:1942, 1982
    3. doi:10.1002/14651858.CD012097
      .

    Histology A text and atlas. Michael H.Ross and Wojciech Pawlina 5th Edition 2006

    External links
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