CATARACT. 1 17 



the pupil is contracted, and often filled with lymph ; a pink zone 

 surrounds the cornea, formed by small vessels from the sclerotica ; 

 there is intolerance of light, dimness of vision, a burning pain in 

 the eye, and an aching pain over the brow. 



Treatment. — The inflammation should be subdued by active an- 

 tiphlogistic means, such as bleeding, purging, and leeching. The 

 absorption of lymph is to be promoted, and its fresh effusion ar- 

 rested by the administration of small doses of calomel and opium 

 every four hours, until the gums become affected. The pupil should 

 be kept w^ell dilated by belladonna or stramonium, and the pain must 

 be relieved by anodyne fomentations and nightly doses of opium. 



Artificial Pupil. — It is often necessary to form a new aperture in 

 the iris, owing to the pupil having been obliterated by inflammation. 



CATARACT. 



Is an opacity of the lens or its capsules. It may be caused by in- 

 flammation or injury, but is more frequently the result of impaired 

 nutrition. There are different varieties of cataract, designated by 

 the terms, hard, soft, radiated, capsular, &c. 



Symptoms. — The vision becomes gradually impaired, and objects 

 appear as if surrounded by a mist or cloud. The sight is better in the 

 evening, or after the application of belladonna, because the pupil being 

 dilated, more light passes through that part of the lens which may 

 yet be transparent. The pupil is active, and behind it is an opaque 

 body of a grayish-white or amber colour. The catoptric test is the 

 most certain mode of distinguishing it from amaurosis and glaucoma. 

 When a lighted candle is held before the healthy or amaurotic eye, 

 three images of it may be seen: an erect image that moves upwards 

 when the candle is moved upwards, which is produced by reflection 

 from the surface of the cornea ; another erect image, produced by 

 reflection from the anterior surface of the lens, which also moves 

 upwards when the candle moves upwards ; and a very small inverted 

 image, that is reflected from the posterior surface of the crystalline, 

 that moves downwards when the candle is moved upwards. In 

 cataract this inverted image is from the first rendered indistinct, and 

 soon abolished ; and the deep erect one is soon abolished also. 



Treatment. — There is no cure but by an operation, which should 

 be deferred until the patient is in good health and condition. If 

 the iris moves freely, and there is no tendency to vascular disturb- 

 ance in the eye or head, the chances are favourable. — There are 

 three modes of operating, before performing either of which, the 

 pupil should be dilated by belladonna or stramonium. 



Extraction, — An incision is made throiigh one half of the circum- 

 ference of the cornea, the capsule of the lens lacerated, and the 

 cataract extracted entire. 



Couching or Depression, — The object of this operation is to re- 



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