Glaucoma / by Priestley Smith.

  • Smith, Priestley.
Date:
[1891]
Catalogue details

Licence: Public Domain Mark

Credit: Glaucoma / by Priestley Smith. 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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    remove these difficulties, and to confirm the essential importance of the obstructive changes. Let us examine the nature of these changes, and the manner of their occurrence in the several varieties of glaucoma. Pathology of Primary Glaucoma.—Predisposing Causes.—Primary glaucoma is met with in association with various general disorders, and it is met with in persons who appear otherwise healthy; it cannot be regarded as a local manifestation of any particular constitutional disease. The one condition to which it bears a clear relationship is age^ the large majority of all the cases met with being in persons who have passed their fiftieth year. With the advance of life the healthy crystalline lens increases continually in size; during the forty years between the ages of twenty-five and sixty- five it adds about one-third to its volume, and about one-tenth to its linear dimensions {vide Fig. 126). The structures which surround the lens Fig. 126.* Diagram showing the Relative Sizes of the Average Lens at 25 and 65 Years of Age. attain their full size at the beginning of adult life if not earlier; the diameter of the cornea for example increases little if at all after seven or eight years of age.f Hence it comes about that as age advances the lens gradually encroaches upon the space in which it lies, compensation being obtained at the expense of the aqueous chamber; the anterior chamber becomes shallower, the circumlental space—the space which separates the margin of the lens from the ciliary processes—becomes narrower {vide Figs. 127 and 128). The change is a physiological one, and is entirely compatible under all ordinary circumstances with the perfect integrity of the eye, but it increases the liability to disease of a certain kind—the obstructions in the path of the intra-ocular fluid which characterize glaucoma arise more easily where the channels are already * From *'Brit. Ophth. Society's Trans. Vol. ill. t Emmert. **Auge und Schaedel, Berlin, 1880, p. 21.