Descemet's membrane

Membrane in the cornea of the eye

English: /ˈdɛsəmeɪ/LocationCornea of eyeIdentifiersLatinl. limitans posterior corneaeMeSHD003886TA98A15.2.02.021FMA58309Anatomical terms of microanatomy

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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

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).

References

^ "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.
^ Johnson DH, Bourne WM, Campbell RJ: The ultrastructure of Descemet's membrane. I. Changes with age in normal cornea. Arch Ophthalmol 100:1942, 1982
^ Stuart AJ, Virgili G, Shortt AJ (2016). "Descemet's membrane endothelial keratoplasty versus Descemet's stripping automated endothelial keratoplasty for corneal endothelial failure". Cochrane Database Syst Rev (3): CD012097. doi:10.1002/14651858.CD012097.

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

External links

Histology image: 08002loa – Histology Learning System at Boston University
Diagram at dryeyezone.com

Anatomy of the globe of the human eye

Fibrous tunic
(outer)

Sclera	Episcleral layer Schlemm's canal Trabecular meshwork
Cornea	Limbus layers Epithelium Bowman's Stroma Dua's layer Descemet's Endothelium

Uvea / vascular
tunic (middle)

Choroid	Capillary lamina of choroid Bruch's membrane Sattler's layer
Ciliary body	Ciliary processes Ciliary muscle Pars plicata Pars plana
Iris	Stroma Pupil Iris dilator muscle Iris sphincter muscle

Retina (inner)

Layers	Inner limiting membrane Nerve fiber layer Ganglion cell layer Inner plexiform layer Inner nuclear layer Outer plexiform layer Outer nuclear layer External limiting membrane Layer of rods and cones Retinal pigment epithelium
Cells	Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine cell) → Retina ganglion cell (Midget cell, Parasol cell, Bistratified cell, Giant retina ganglion cells, Photosensitive ganglion cell) → Diencephalon: P cell, M cell, K cell, Muller glia
Other	Macula Perifoveal area Parafoveal area Fovea Foveal avascular zone Foveola Optic disc Optic cup Ora serrata

Anatomical regions
of the eye

Anterior segment	Adnexa (Eyebrow, Eyelid, Conjunctiva, Lacrimal system, Orbit) Fibrous tunic Anterior chamber Aqueous humour Iris Posterior chamber Ciliary body Lens Capsule of lens Zonule of Zinn
Posterior segment	Vitreous chamber Vitreous body Retina Choroid