Superficial Inflammation of the Cornea is a very frequent disease in small children ; generally as a symptom of scrofula: It shows a great tendency to recurrence. On healing, more or less dense scars (conical opacities) are left, which may give rise to considerable disturbance of vision, especially when they are situated in the centre of the cornea. If the affection persists for some time, ulceration may ensue ; and in particularly obstinate cases this may lead to perforation of the cornea, escape of the aqueous humour, and prolapse of the iris. Ulcers of the cornea may arise also after superficial injuries ; frequently they spread very rapidly (especially when occurring simultaneously with an affection of the lachrymal sac), and they heal but slowly, and with the formation of dense scars.
Deep-seated Inflammation of the Cornea (Keratitis) is an affection which runs a very protracted course. As a rule, both eyes arc involved simul taneously ; sometimes one following the other after a longer or shorter interval. In most instances inherited syphilis is the cause of the disease, although it may arise also from neglected chronic catarrhal conjunctivitis. The younger the patient, the more favourable, as a rule, is the course of the affection. Deep-seated opacities usually persist.
Purulent Inflammation of the Cornea occurs most frequently as a result of injuries. If the pus accumulates in the anterior chamber of the eye, it will, in most cases, be found necessary to remove it by an operation.
Injuries and Wounds of the Cornea, which may he caused by the entrance of foreign bodies, or by violence, etc., should always receive the immediate care of a physician in order that grave complications may be avoided. The same applies to erosions by chemicals, etc.
Buphthabnia, or Ox-Eve, is a congenital affection of the cornea (see Plate XII., Fig. 2) which is characterised by an excessive collection of aqueous humour, causing all parts of the eyeball to bulge. The cornea is sometimes clear, but, as a rule, slightly opaque. Blindness is certain to follow, if operation, which consists in the excision of part of the iris, is delayed.
Treatment of affections of the cornea should always be left to an ophthalmologist, owing to the diversity of the symptoms. In general it may be said that hot compresses are better borne than cold ones. Warning should be given against the indiscriminate application of eye-waters, as well as against the inappropriate massage of the eye, by which many quacks have caused blindness in cases in which it would otherwise have been possible to save the eye.
Choroiditis.- Inflammation of the choroid coat of the eyeball ; a disease which may occur at any time in life. Beginning as an inflammation without pain or outward evidences of its presence, it leads gradually to an impairment of vision, due to the involvement of the retina and the vitreous body. The patients notice that they see badly when the evening twilight comes on, that there are blanks in the visual field, and that objects appear distorted. There are also x'arious light disturbances, such as flickering before the eves, sparks, points of fire, etc. This disease, which can be
recognised only by aid of the optical mirror (ophthalmoscope), pursues a very insidious course. .1.5 it progresses, complete blindness may result. The principal causes are syphilis and tuberculosis, and, aside from these, general nutritive disturbances, anemia, scrofula, etc. The best results from treatment are obtained in the syphilitic cases.
Inflammation of the Iris.—.\ comparatively severe affection which usually occurs in consequence of a general disease, most frequently of syphilis. It may occur also as a part symptom of diabetes mellitus, gonor rhoea, or rheumatism. The disease manifests itself by redness of the eye. by dread of light, and by violent pains radiating into the forehead. Medical treatment is necessary without delay, as otherwise adhesions and other disturbing conditions develop which may give rise to considerable impair me it of sight, or even to GLAUCOMA and consequent loss of vision. The physician will treat the local condition as well as the general health, thus guarding against recurrences. Resting the eves is an essential requirement, and it is advisable to wear dark-coloured glasses.
Diseases of the Retina.—Affections of the inner coat of the eve, like those of the optic nerve, are recognisable only by means of the ophthalmo scope. As a rule, they are painless, except when the disturbance has reached an advanced stage.
Inflammation of the Retina usually manifests itself in a bloodshot con dition of this membrane, and is almost invariably a sign of some general disease, such as syphilis, inflammation of the kidneys, diabetes, heart-disease, or arteriosclerosis. Anything that improves the general health will usually help the eyes at the same time. Chronic inflammations lead to irrecoverable blindness.
Separation of the Retina is usually the outcome of a very intense form of near-sightedness, and is always a serious matter, even though it is sometimes possible to prevent it from causing blindness. It may arise also from a tumour of the inner eye, and in such cases it is necessary to remove the affected eye immediately, on account of its menace to life.
A deposit of pigment in the retina may occur as a symptom of hereditary syphilis, or as a consequence of blood-relationship in parents, and occasionally without any determinable cause. These troubles lead slowly but surely to blindness.
Diseases of the Optic Nerve.--Injury or disease of the optic nerve results in acute or gradual blindness. Sudden hemorrhage into the retina, and acute poisoning from wood-alcohol, lead, quinine, and other substances, result in transitory or in permanent blindness. The pressure of a tumour within the brain affects the optic nerve, and if the pressure continues for any great length of time it usually induces blindness. Gradually increasing blindness may be due to a number of other causes, all of which require expert diagnosis.
See also the articles AMAUROSIS ; AMBLYOPIA ; BLINDNESS ; GLAUCOMA ; HEMERALOPIA ; NYCTALOPIA ; SCOTOMA ; SIGHT, DISTURBANCES OF ; SQUINTING.