. Annual and analytical cyclopaedia of practical medicine . The cause of the con-genital form is supposed to be due tosome foetal disturbance operating dur-ing the development of the lens. In thepolar variety, which, in reality, is oneof the true cataractous forms, the opacityassumes the figure of a star or rosette. with its radii extending toward the pe-riphery. It has been seen to follow con-tusions of the globe, to appear as a partof pigmentary retinitis, and exliibit it-self as a consequence of uveitis. Thepost-natal form, as a rule, is the per-manent result of rupture of a cornealulcer, b
. Annual and analytical cyclopaedia of practical medicine . The cause of the con-genital form is supposed to be due tosome foetal disturbance operating dur-ing the development of the lens. In thepolar variety, which, in reality, is oneof the true cataractous forms, the opacityassumes the figure of a star or rosette. with its radii extending toward the pe-riphery. It has been seen to follow con-tusions of the globe, to appear as a partof pigmentary retinitis, and exliibit it-self as a consequence of uveitis. Thepost-natal form, as a rule, is the per-manent result of rupture of a cornealulcer, by which the anterior capsule ofthe lens is brought into contact with theinflamed cornea, leading to prolifera-tion of the epithelial cells of the lensoccupying the position of the pupillaryarea, with the formation of a subcapsularopacity after the reformation of theanterior chamber; this being in addi-tion to the nebule, which, as a rule, butfaintly marks the site of the previouscorneal ulceration. When, in addition,there is a deposition upon the anterior. Capsular cataract. (Becker.) face of the capsule which in itself isirregular, opaque, and thickened di-rectly beneath, the condition is knownas anterior pyramidal cataract: in real-ity an opacity in both the lens and itsanterior capsule. The disturbance invision depends upon the extent of thecapacity. Treatment, as a rule, is un-availing, except the possibility of anoptical iridectomy should the opacity belarge and the pupil small. When the opacity is situated at theopposite pole of the lens, the conditionis designated as posterior polar cataract,or posterior pyramidal cataract. In mostinstances the latter form, which is nota true cataract, is congenital in type, andis due to some interference with the in-complete disappearance of the hyaloidartery. It is recosfnized as a small dot 84 CATARACT. SYMPTOMS. or point on the posterior capsule at theposterior pole of the lens, projectingbackward into the vitreous humor. Trueposteri
Size: 3196px × 782px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthors, bookcentury1800, bookdecade1890, booksubjectmedicine
