A practical treatise on the diseases of the eye / by William Mackenzie ; to which is prefixed an anatomical introduction explanatory of a horizontal section of the human eyeball by Thomas Wharton Jones.

  • Mackenzie, William
Date:
1854
Catalogue details

Licence: Public Domain Mark

Credit: A practical treatise on the diseases of the eye / by William Mackenzie ; to which is prefixed an anatomical introduction explanatory of a horizontal section of the human eyeball by Thomas Wharton Jones. Source: Wellcome Collection.

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    of mercury. Benefit will also be derived from keeping up a continued discharge from the neiglibourhood of the head. § 6. Amavrosis from morbid changes in the membranes, or in the bones of the cranium. There are various states of the dura mater, and of the bones of the skull, capable of producing amaurosis; such as ossifications of the dura mater, especially when they are in the form of sharp spicula;, atheromatous thickenings, fungous tumours of that membrane, and exostoses proceeding from the inner table of the skull. We have no means of positively ascertaining during life the existence of such organic changes. The symptoms are exceedingly similar to those attendant on diseased formations in the brain. Severe cephal^a, or fixed pain in the top of the head, palsy of some of the muscles of the eye, either the abductor or the muscles stimulated by the third nerve; other of the special senses affected besides sight; weakness and stiffness in the limbs, followed by pain, spasms, and convulsions, are symptoms which lead to the suspicion of pressure on the basis of the brain, or on the pons Varolii. The symptoms increase for a time very slowly; first one eye is affected, then the other; then the organs of hearing. In many of the cases there takes place at last a protrusion of the eyes out of the orbits; a symptom indicative of great derangement in the bones forming the basis of the cranium, of the dura mater covering the sella turcica, or of the upper part of the orbits. (See Case 10], p. 81.) The morbid changes of the bones, which induce amaurosis, are found chiefly in the basis of the cranium. In these cases caries is sometimes met with, but much more frequently exostosis of different forms. In some instances, innumerable spicule of bone project into the cavity of the cranium, so sharp that they readily wound the finger. IBeer preserved the skull of a lady who had been totally blind, and for some weeks before her death insensible, in which there was scarcely any part within the cranium which was not studded with sharp exostoses. In such cases the bones are sometimes very thin, the diploe being almost completely wanting. In an amaurotic boy, who for a short time before his death was insane. Beer found, on dissection, a spine of considerable length by the side of the sella turcica, perforating the optic nerves at their junction. Those who have suffered from rachitis in youth, from syphilis, or from gout in middle age, are more liable than others to thickening and other morbid changes in the bones of the cranium. Falls or blows on the head slowly bring on affections of the coverings of the brain. In all the cases mentioned by Beer, it appears that the complaint in the head and eyes began after sudden cooling of the head, followed by rheumatism, which, though slight in its commencement, had fixed itself in the fibrous investment of the skull. ' The morbid formation, which I have ventured (page 9) to call chloroma, and which appears to be of a fibro-plastic nature, is found to affect in some cases the pericranium; in others the dura mater, and occasionally both these membranes at once. Such appears to be the 3x3