Text-book of ophthalmology . light backward curvature, across theoptic nerve. With increase of tension, it recedes more and more, and thusforms the glaucomatous excavation. A second reason for the production ofpathological changes lies in the fact that within the foramen sclera?, andparticularly within the limits of the lamina cribrosa. the optic nerw istightly inclosed between firm, fibrous walls, a thins that occurs at no otherHere, therefore, when swelling of the optic nerve takes . constriction and strangulation of it may readily occur. The foramenlinprly. in tliis case play a part like th
Text-book of ophthalmology . light backward curvature, across theoptic nerve. With increase of tension, it recedes more and more, and thusforms the glaucomatous excavation. A second reason for the production ofpathological changes lies in the fact that within the foramen sclera?, andparticularly within the limits of the lamina cribrosa. the optic nerw istightly inclosed between firm, fibrous walls, a thins that occurs at no otherHere, therefore, when swelling of the optic nerve takes . constriction and strangulation of it may readily occur. The foramenlinprly. in tliis case play a part like that which the fibrous ringof the hernial orifice for the viscera lying in front of it. DISEASES OF THE OPTIC NERVE 603 That portion of the optic nerve situated in front of the lamina cribrosa,in the interior of the eye itself, is the head of the optic nerve ^papilla nervioptieij. It is the part of the optic nerve which even during life can be seen bymeans of the ophthalmoscope. The name papilla was selected by the older. Fig. 265.—Longitudinal Section through the Optic Nerve Head. Magnified 20 X nerve fibers of the trunk of the nerve, whenever they are medullated. are stained black byWeigerts hematoxylin stain. The medullary coating extends as far as the lamina. Proceeding frombehind forward, the sclerotico-chorioidal canal shows first a dilatation, then a contraction. E, physio-logical excavation.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecteye, booksubjectophth
