The crystalline lens system : its embryology, anatomy, physiological chemistry, physiology, pathology, diseases, treatment, operations and after-changes ; with a consideration of aphakia / by Louis Stricker.

  • Stricker, Louis, 1863-
Date:
1899
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Licence: Public Domain Mark

Credit: The crystalline lens system : its embryology, anatomy, physiological chemistry, physiology, pathology, diseases, treatment, operations and after-changes ; with a consideration of aphakia / by Louis Stricker. 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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    Leipsig, 1880), who believed that the zonula consisted of a system of merid- ional]}- placed fibres, which take their origin from the ciliary body and the orbicularis eiUaris, and that they are independent of the vitreous body, and he further denies the existence of Petits Canal. Later investigators, Schoen22 and Topolanski,23 agree almost in toto with Czermak. As the result of his investigations, Czermak states that in early foetal life, the space between ciliary body and lens is filled up by a large number of foetal cells, which arrange themselves in rows, leaving spaces between them. These cells elongate, forming line threads or fibrillae arranged meridional ly, hence the zonula is not a membranous struc ture, but a complicated system of fibres from the beginning. In a six and one-half month foetus he found the entire posterior chamber occupied by the zonula, and a condition pres- ent never seen in a fully developed eye. namely, pencils of these rays of fibrillae extending from the peripheric portion of the iris and the most anterior part of the ciliary body. Later on. as the result of rarefaction, these fibres are restricted to the posterior portion of the posterior chamber, and the pupillary membrane disappears at the same time. He looks itpon the zonula as of mesodermic origin, derived from the portion of the em- bryonal vitreous which fills up the space destined to become the posterior chamber, and that this tissue is modified both physically and chemically so as to serve its function. Others again, as Abey 24 and Kuhnt and Berger,25 return to the view that the zonula is a membrane, the fibrillae Berger considered as fibrillae which support the membrane. Finally, E. Treacher Collins,26 as the result of the examination of an eye. enucleated from an infant three months old under the supposition that it contained a new growth, and which was found to contain a persistent hyaloid and exhibited fibres of the suspensory ligament in all stages of their development, and the subsequent examination of several foetal eyes, formu- lated the following idea as to the development of the zonula. For a long time the primitive lens remains in contact at its sides with the portion of the secondary ocular vesicle destined subsequently to become ^Zonula mid Grenzehaut des Glaskorpers. Graefe's Arch.. Vol. XXXII, B. 2. p. 149, 188G. [Jber den Bau der Zonula und Umgebung nebst benierkunffou uber das Albinotische Auge. (Jraofe's Arch., Vol. XXXVIII, B. 1. 1891. 24 Der Canalis Petit und der Zonula ZInnIi beim Mensch und bej Wirbel- thleren. Graefe Arch.. Vol. XXXVIII, B. I, 1882. 25Beitrag ztir Anatomic der Zonula Zinnii Arch, fur Oplh. XXVITI. B. II, 1882. 26 On the development and abnormalities of the Zonula of Zinn. The Uoyal Ixmdon Opth. Hospital Reports, Vol. XIII. Vol. I, p. 81.