The development of the posterior elastic lamina of the cornea or membrane of descemet / by E. Treacher Collins.

  • Collins, E. Treacher (Edward Treacher), 1862-1937.
Date:
[1892]
Catalogue details

Licence: Public Domain Mark

Credit: The development of the posterior elastic lamina of the cornea or membrane of descemet / by E. Treacher Collins. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    antero-fibrovascular sheath. The posterior elastic lamina is still only seen as an exceedingly delicate line, and nothing of a homogeneous layer is yet visible between the anterior epithelium and substantia propria of the cornea. In a human foetal eye, said to be of the sixth month, Bowman's membrane, the anterior elastic lamina, is very distinctly seen, and the posterior elastic lamina is con- siderably wider than it was at the fourth month. It is evident, then, from this, that in mammals there is a stage in the development of the cornea where no elastic membrane is present. In man, when a very delicate rudiment of the posterior elastic lamina is just discernible, it is already lined by endothelial cells, and from this time onward it gradually increases in thickness. The question then suggests itself: Is the posterior elastic lamina a product of the endothelial cells lining it ? I have, in former writings,* attempted to show that the two other hyaline membranes in the eye, viz., the capsule of the lens and the membrane of Bruch, are the product of epithelial cells lining them, mainly on patho- logical grounds. Can Descemet's membrane, in the same w^ay, be shown to be the product of the cells lining it ? I may, in the first place, point out this difference: the cells lining the lens capsule are the product of cuticular epiblast, those lining the membrane of Bruch are derived from neural epiblast, whilst those lining Descemet's mem- brane are generally believed to be mesoblastic in origin. Otto Schirmerf showed that after wounds of the lens capsule the gap first became closed by cells derived from. those lining the capsule, and that afterwards a new hyaline layer made its appearance, presumably the pro- duct of these cells. When Descemet's membrane is wounded and its ends * Trans. Oplitli. Soc, vol. xii, p. 89. Researches into the Anatomy and Pathology of the Eye, p. 13-18, and 88-91. t Archiv f. Ophth., Bd. xxxv, ab. 1, s. 220.