Staphyloma (from e—racpuxn, a grape) consists of an opacity with distention of the cornea, according to Scai.pa; while according to Richter, there must be also an adhesion of the iris to the cornea, but it may certainly be both. The eye has a disgusting appearance, from the variegated or mottled look of the cornea, which is alternately of a white, bottle blue, or purple colour. Sometimes only the one half of the cornea is affected, which is commonly the lower; sometimes the cornea forms one uniform convex projection, while at others there are two or more, giving it a nodulated appearance. The distended condition follows a superabundant secre tion of the aqueous humour, for in many cases the individual has indistinct vision with remarkable projection. Staphyloma is the result of acute, especially the purulent form of, ophthalmia, and occurs frequently in children after small-pox. From the projection of the eye-ball, it is exposed to the sun, air, and to particles of dust producing friction between it and the eye-lids, and rendering it a most distressing complaint; and it not unfre quently ends in ulceration of the cornea. This af fection, if vision be totally gone, is to be treated by piercing the projected part of the cornea with a tenaculum, pulling the eye-ball gently forwards from the eye-lids, which ought to be kept out of the way by an assistant, and then cutting away the whole projection with a scalpel at once. The eye lids are then to be gently closed, and the eye bathed with hot water for the remainder of the day, and afterwards to be treated with mild collyria. On the second or third day, the wound is filled with coagulable lymph, which gradually cicatrizes with an opaque horny texture, not unlike the cornea. Some recommend the establishment of an ulcer at the lower margin of the cornea; while others the inserting of a seton of fine thread, but unless the adhesive inflammation accompanies the ulcerative, it fails.
Cataract, (from x,t-ra:cerrea, to confound, is either an opacity of the crystaline lens, its capsule, or the fluid between these, or a combination of them all. The varieties of this disease, according to ophthal mologists, are truly ludicrous, and would form a rhyme for Caleb Quotam. They may, with every propriety, be reduced from upwards of fifty to four. The capsular, the lenticular, and the milky, with a combination of these, and it is even very difficult to discriminate between these four in the living body. When examining the diseased eye, the sound one should be closed or shut up, in order to prevent the motions of the one influencing the other. The capsular cataract presents a general white surface behind the pupil, producing nearly total blindness, with dilated pupil, which is not affected by any light; and when belladonna is rubbed on the eye lids, no ring is seen around this white spot. This species is generally consequent un local causes. The lenticular begins in the centre of the lens, producing opacity behind the pupil, with dilata tion, so that although vision is no doubt impaired, yet the patient can see in an obscure light, as the twilight, in consequence of the rays being admitted around the lens; and there is almost always a clear deep ring around, particularly if the pupil be di lated with belladonna. This species commonly arises from constitutional causes, rendering the disease idiopathic. The milky variety, termed al so cataracta morgagniana, begins in the liquor morgagni, and involves the lens, which degenerates into a thin milky fluid; it also generally affects the capsule, so as to form a combination of these three textures. Cataract is sometimes complicated with adhesion of the iris, obliteration of the posterior chamber of the aqueous humour, the latter of which is termed false or spurious. This disease is either idiopathic or local, is very often hereditary, and also congenital; the hereditary disposition being very extensive, frequently affecting'a whole family. In the constitutional species, the individual begins to complain of weakness of sight, that he cannot see distant objects, has a mistiness or cloudiness over his eyes, and that when he turns his back to the light, or when the sun begins to set, he sees more distinctly; and he also occasionally sees more distinctly on the one side of the axis of vision than on the other. A candle appears to him
to have a halo around it, and as he recedes from it, the halo becomes broader and the flame more in distinct. These defects gradually increase until he can only distinguish between light and darkness, and then the opacity may be perceived behind the pupil, having either a gray, silvery, dead white, yellow, brown, or dirty black appearance. In some rare cases, the opacity begins with two or three white spots. Local or accidental cataract is consequent on inflammation from wounds, and is sometimes so gentle and insidious, that the patient has not been conscious of its formation. With the exception of the congenital, we never succeed in curing cataract but by an operation, and before it is performed, several circumstances are to be at tended to. We must distinguish between this disease and amaurosis, and be careful that the two affections are not co-existent; also between cataract and glaucoma, and there must be no inflammatory tendency, the eye ought to be free from all other disease, and the patient to be in a healthy state. A number of other points are mentioned by ophthal mologists, which do not merit attention. The in flammatory tendency is characterized by flashes of light, fiery sparks, pain in the eye, orbit, or fore head. When both eyes are effected, the one should be operated on before the other.
There are various operations for this disease, as couching, depression, displacement, and extraction. Under the three first, there are operations posterior and anterior to the iris; under operations posterior to the iris, there are simple depression, the depres sion of Scarpa, and the reclination of \Villberg and Wer. Under operations anterior to the iris, there are the reclination of Langenbeck and keratonyxis. Before any of these operations is performed, the patient should take a brisk cathartic the preceding day, and any other course of preparation, as re commended by some, is unnecessary. An hour or so before operating, the extract of belladonna should be rubbed on the eye-lids to dilate the pupil, when the operation of couching is performed. The patient should sit on a low chair before a clear light, with an assistant behind, who is to raise with his fingers the upper eye-lid, while the operator depresses the lower; the surgeon then inserts Scarpa's needle, previously moistened with the tears of the patient, about a line and a half from the cornea, and half a line below its horizontal diameter, at the outer canthus of the eye, directing the needle towards its centre; the hand of the ope rator resting on the patient's cheek. The needle is to be seen anterior to the capsule of the lens, with the one flat surface upwards, and the other downwards, and the lens is then to he depressed to the bottom of the vitreous humour, keeping the in strument above the lens for a few seconds. The motions which are described by opthalmologists, to be performed in this simple process of depression. resemble the broad sword exercise. If the lens does not rise again, the needle is to be cautiously withdrawn; but if it ascends, the depression is to be repeated. The operation of reclination of \Vil berg is almost the same. Langenbeck performs re clination through the cornea anterior to the iris, with a curved needle, the convexity of the instru ment being towards the lens. Kcratonyxis consists in entering a spear-pointed needle through the cor nea, at its inferior margin, lacerating the capsule of the lens laterally, and either merely making a small aperture in the texture of the lens, or by breaking it up, and endeavouring to bring it into the anterior chamber of the aqueous humour, where it is ulti mately dissolved and absorbed by its agency. Care must be taken to prevent the escape of the aqueous humour. This operation is the simplest and safest which can be performed for cataract, whether capsular, milky, or lenticular. It is advo cated by Conradi, Mer, Saunders, Buckthorn, Langenbeck, and \Valther, with a slight variation in some trifling points.