The principles and practice of ophthalmic medicine and surgery / By T. Wharton Jones.

  • Jones, Thomas Wharton, 1808-1891.
Date:
1863
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Licence: Public Domain Mark

Credit: The principles and practice of ophthalmic medicine and surgery / By T. Wharton Jones. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    both conjunctiva and sclerotica are injected at the same time, the pink hair-like vessels of the sclerotica are seen stationary through the Fig. 5. Sclerotic vascu- larity. Conjunc- tival vas- cularity. larger meshes of the sliding conjunctiva. But when the conjunctiva is very much injected, the state of the sclerotica cannot be seen. Growths and tumors on the white of the eye are to be examined as to whether they have their seat in the conjunctiva only, as in pterygium —or are imbedded in the subconjunctival cellular tissue, as in hydatid cysts, or have their roots in the sclerotica, as in trichosis hulbi. The sclerotica may be found in some part unnaturally prominent and bluish-black—sclerotic staphyloma. State of the cornea.—The prominence and breadth of the cornea, the state of its margin, its connection with the sclerotica, and its trans- parency and non-vascularity in the mature and healthy state, as also its relations to the iris, and its composition of three principal layers of different tissue, viz., the proper substance, forming its principal thickness ; the thick epithelium, or conjunctival layer on its anterior surface; and the membranes of Descemet on its posterior surface, are circumstances to be had in remembrance in examining whether it be the seat of disease. In order to ascertain the prominence of the cornea, a profile exa- mination of it should always be made. The cornea may be found un- naturally prominent; the prominence may be spherical, as in dropsy of the aqueous chambers after corneitis, or conical, as in conical cornea. Besides these unnatural states of prominence, in which the transpa- rency of the cornea is usually still more or less retained, there is the opaque prominence of staphyloma, which may be either partial or complete. The cornea may be found unnaturally flat. By a profile examination, also, it will be seen in any doubtful case whether an opacity is seated in the cornea, or not. Facets and small ulcers of the cornea will also be detected. The usual diameter of the cornea is 9-20ths of an inch transversely, somewhat less vertically, the outline of the cornea not being quite circular, but rather oval, and this in the literal sense: its small end