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, edited 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, edited by G.E. de Schweinitz. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    ward tlie shorter zonula takes place: Edopialcntiscongenita. rt‘ the upper zonula is shorter than the lower, the lens is displaced u[)ward and the dislocation increases as the lower zonula gradually atrophies and disappears. Such a dislocation upward results in diminution of the upper angle of the anterior chamber and tremulousness of the iris, which loses the support of the lens. The .same phe- nomena are observed after rupture of the zonula by a blow on the eye, a not infrequent accident. The lens may suffer only partial dislocation to one side, so that the margin is seen as a sharp circular line within the pupil (snblaxatio lentis), or it may be thrown into the vitreous body (luxatlo lentis). In the latter case the normal gray color of the pupillary reflex is changed to black, the entire iris is tremulous, and the lens is .seen, by lateral illumina- tion or with the ophthalmo.scope, as a spherical body freely movable within the vitreous. In favorable cases it becomes fixed after a time by adhesioms, cataract develops, and the lens contracts; usually, however, a movable lens gives rise to glaucoma, [)robably by irritating the ciliary proc- esses which .secrete the a([ueons humor. Even sublnxa- tion may have this effect. A partial dislocation, whether congenital or traumatic, is very apt to become complete. Complete luxation may be anterior (although rarely), and a shrunken and turbid, or a .semitransparent, lens is sometimes found in the ante- rior chamber. If the lens is transparent, the yellowish lu.ster of its margin gives the impression of a large drop of oil in the anterior chamber. In violent contusions with ru])ture of the .sclera the lens is sometimes bodily ejected ft’om the eye, and the same accident may occur in j)crforation of the cornea by extensive ulcerations if the patient strains during the examination. Spontaneous luxation into the vitreous chamber is caused by atrophy of the zonula in con.sequenee of li(|ue- faction of the vitreous humor occurring in severe myopia, anterior choroiditi.^?, or retinal separation. Atrophy of the zonula .sometimes occurs through the shrinking of an