By a concussion of the orbital region, and especially of the eyeball, all sorts of injuries may be inflicted, from those involving the cornea to deep lesions which leave little or no superficial evidences, but cause partial or complete blindness. Detachment of the retina, for instance, is one of the possibilities of such conditions. Intra-ocular hemorrhages or dislocation of the lens, with traumatic cataract, may also occur.
The sclerotic may be ruptured with or without the presence of a foreign body, in which case the contents of the eye may have partially or completely escaped. An eye which has collapsed from these causes offers an almost hopeless field for the general or special surgeon, and little can be done, save possibly for cosmetic purposes. There is danger of sympathetic ophthalmia, and it may be a question whether evisceration, i. e., completion of the evacuation, may not be the wiser course.
Perforating wounds, even when inflicted by minute bodies, have dangers of their own, including the possibilities of infection. The interior mechanism of the eye is so easily disturbed, and its transparent media so easily clouded, by the results of accident or hemorrhage, that even apparently trivial injuries may be followed by disturbances of vision.
Treatment.
—The general principles of treatment of all such injuries should include, first, the removal of every detectable foreign body, followed by the application of cold, and the use of antiseptic eye-washes, which, however, must not be used too strong lest they irritate. Saturated boric-acid solution is perhaps as strong as anything which is permitted, while even this may occasionally require dilution. In addition to this the use of atropine solution is always indicated. It has the double effect of soothing and allaying pain and of dilating the iris into a narrow ring. With such measures as these it may be possible to save vision; at all events it will limit reaction and prevent harm.
DISTURBANCES OF INNERVATION.
The nerves which supply the eye and its adnexa may undergo injury, either within the orbit or within the cranium, or in their course from one to the other. The paralyses may be caused by syphilis, by intracranial tumors, or by injury. A careful study of the areas and nerves involved will sometimes lend considerable help in diagnosis, both in traumatic and pathological cases. Thus diplopia, or double vision, may be caused by paralysis of the external rectus on one side, by which its antagonistic internal rectus is permitted to swerve the eye too much to the inner side and away from the normal axis of vision required for single sight. When there is complete paralysis of the third nerve there may be drooping of the eyelid, called ptosis, with impaired motion of the eye, upward, inward, or downward. The eye will roll outward because the external rectus is supplied by the sixth nerve. There will also be dilatation of the pupil, with loss of accommodation. When the upper lid is raised there is also double vision. This third-nerve paralysis, however, is not always complete, and diplopia may result only when the eye is directed in a certain way. When the sixth nerve is paralyzed the eye is rolled inward, and again there is diplopia. When the fourth nerve is paralyzed the eye is but slightly displaced upward and inward. When the sympathetic nerve is involved there will be protrusion of the globe with dilatation of the pupil. This will be accompanied by flushing of the face.
MUSCULAR AND ACCOMMODATIVE DEFECTS.
Detection of errors of accommodation is practically a specialty within a specialty, while the various forms of strabismus, or deviation of the eyes from their normal axes, depend largely upon regulation of accommodative errors.