Atlas of the external diseases of the eye : including a brief treatise on the pathology and treatment / by O. Haab ; authorized translation from the German edition by G.E. de Schweinitz.

  • Haab, O. (Otto), 1850-1931.
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: Atlas of the external diseases of the eye : including a brief treatise on the pathology and treatment / by O. Haab ; authorized translation from the German edition by G.E. de Schweinitz. Source: Wellcome Collection.

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    of a ciliary congestion is more bluish, pink, scarlet or crushed raspberry (Plates 21 and 30, 6). The differences in color and in localization are readily explained by the arrangement and distribution of the blood-vessels concerned in each form of congestion. Conjunctival congestion is due to abnormal distention of the conjunctival vessels, barely visible in the normal eye on account of their tenuity. The vessels in the sclerotic portion of the conjunctiva make their appearance at the fornix, and from all sides radiate forward and out- ward toward the cornea, breaking up into arborizations as they proceed and thereby becoming more and more minute. This enlargement furnishes the anatomical explanation of the diminution of the intensity of a conjunctival conges- tion as it approaches the cornea. As these vessels are very superficial, they show the true color of the blood when overfilled, which in thin layers is a yellowish-, < d. Moreover, the conjunctival vessels can be recognized by their mobility with the shifting of the conjunctiva, which is but loosely attached to the sclerotic, especially at some distance from the cornea. This mobility is often of ser- vice to clear up any doubts about the nature of such a blood-vessel. The vessels that are responsible for ciliary or circum- corneal congestion are very different in their arrangement and distribution. In the first place, they are situated beneath the conjunctiva. They also are but faintly visible in the normal eye; in fact, only the arterioles are visible, their accompanying venules becoming manifest only when the eye is inflamed. These arterioles proceed from the tendons of the recti muscles, either singly or in pairs, pursue a very tortuous course in radiating lines to the cornea, and suddenly disappear at points several milli- meters distant from the corneal margin, by entering the sclerotic, in which they ramify, and 'contribute largely to the blood-supply of the ciliary body and iris (ciliary re- gion). Their points of entrance into the sclerotic are often distinctly tinted and plainly visible. They are