Paper - A Specimen of Congenital Aphakia occurring in a Human Embryo of Five to Six Weeks
Mann IC. A Specimen of Congenital Aphakia occurring in a Human Embryo of Five to Six Weeks. (1921) Proc R Soc Med. 14(Sect Ophthalmol): 64. PMID: 19981976
A Specimen of Congenital Aphakia occurring in a Human Embryo of Five to Six Weeks
By I. C. Mann, M.B., B.S. (Abstract.)
Cases of congenital aphakia are excessively rare apart from gross degrees of microphthalmos, and indeed the question has been raised as to whether they occur at all in otherwise normal or nearly normal eyes. It is on this account that the following case of failure of development of the lens in an otherwise normal human embryo is reported. The embryo, which is about the 13mm stage (i.e.,between the fifth and sixth weeks), was compared with another human embryo of the same stage known to be normal. The optic cups of both were of approximately the same size (05 mm. in diameter), but while the normal embryo showed a well developed lens vesicle entirely separated from the ectoderm, the abnormal embryo showed no trace of a lens in either eye except that in the right eye there was a small blunt-pointed projection from the deep aspect of the surface ectodermal most in the centre of the pupil. This probably represented an abortive attempt at lens formation. (Slides were shown demonstrating the formation of the lens in normal human embryos at various stages, together with the aphakic eye of the abnormal embryo.)
The president said that Miss Mann had shown an exceedingly interesting and very perfect piece of work of a unique nature, and asked of what material the ingenious model exhibited in connexion with the specimen was made.
Mr. AFFLECK GREEVES said he had had the opportunity of examining microscopically many congenitally abnormal eyes, including microphthalmic eyes, but in all cases there had been a lens, or at least a lens capsule; he had never seen one in which there was no trace of a lens.
Miss MANN (replying to the President) said the model, which represented the aphakic eye x 200, consisted of paraffin wax plates 1 mm. thick, and it was made from drawings of serial sections by the method usually followed in the Anatomical Department of St. Mary's Hospital.
Cite this page: Hill, M.A. (2019, October 15) Embryology Paper - A Specimen of Congenital Aphakia occurring in a Human Embryo of Five to Six Weeks. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Paper_-_A_Specimen_of_Congenital_Aphakia_occurring_in_a_Human_Embryo_of_Five_to_Six_Weeks
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