Penetrating Wounds of the Eyeball

Of all patients treated in hospital for trauma of the organ of vision, penetrating wounds constitute 35-80% and are considered to be severe injuries to the eye.

Depending on localization of the wound there are corneal, lim­bic, corneal-scleral and scleral wounds. Wounds may be of differ­ent shape and size: small — up to 3 mm; middle — 4-6 mm; big — over 6 mm. According to the shape there are linear, irregular, lacerated, stab, stellate wounds, as well as wounds with tissue de­fects. Besides, they may be gaping and adapted when the wound edges touch tightly along the wound.

The penetrating wounds are often accompanied by lens damage (40%), prolapse or incarceration of the iris (30%), haemorrhage into the anterior chamber or the hyaloid body (about 20%), endoph-thamitis due to penetration of infection into the eye. Almost in one third of the patients penetrating wounds are accompanied by in­traocular foreign bodies. The course of the wound process is fre­quently complicated by several complications at once.

Absolute signs of the penetrating wound are gaping wound of the cornea or sclera, prolapse of the inner membranes of the eye, opening in the iris, foreign body inside the eye.

Besides absolute there is a number of doubtful (relative) signs of the penetrating wound: hypotonia (though it may be observed also after eye contusion), occurring due to outflow of the fluid from the anterior chamber, changed shape of the pupil (its protrusion towards fluid outflow). When the penetrating wound is in the sclera, the anterior chamber may become deep due to outflow of the vit­reous and displacement of the iris and lens backward.

In some cases diagnosis of the penetrating trauma of the wound becomes difficult. When the object is very sharp and small adhe­sion and sufficient adaptation of the wound edges come rather fast, the anterior chamber is restored and hypotension disappears. Di­agnosis of the penetrating sclera wounds is often complicated by concomitant injury of the conjuctiva, its oedema and haematoma.

The true signs of the perforating wound are foreign body be­hind the eye, inlet and outlet opening, sometimes exophthalmos be­cause of haemorrhage into retrobulbar fat.

Destruction of the eyeball is the most severe form of the pene­trating wound and does not require special diagnostic techniques. In such case all the ocular membranes are so damaged and loss of eye content is so significant that walls of the eyeball stick togeth­er and it loses its shape. Not infrequently destruction of the eye­ball is combined with injuries of the eyelids, orbit and surrounding tissues. In eye destruction it is impossible to save it, initial enucle­ation is indicated.

All patients with suspected penetrating wound of the eye are ur­gently conducted X-ray review roentgenography of the orbit. In re­vealing shadow of the foreign body it should be localized with the help of additional special methods of investigation. For this purpose we use method of roentgenolocalization by Comberg — Baltin which consists in using of aluminium prosthesis-indicator as a ring of 5 mm with curvature radius corresponding to sclera curvature with open­ing of 11 mm in the center. At a distance of 0.5 mm from the open­ing edge 4 lead points are pressed into the ring, located on the inter-perpendicular meridians. After epibulbar anesthesia this prosthesis-indicator is put on the eye so that lead markers correspond to the limbus for 12, 3, 6, and 9 hours. Two X-ray films are made in direct and side projections. The first film determines the meridian where the foreign body is located as well as its distance from anatomical axis of the eye. The second film helps to establish the distance from the foreign body to the limbus. Exact localization of the foreign body is calculated with the help of special measuring schemes and special tables. However, measuring schemes by the Comberg — Baltin's method are meant for a scheme eye. Therefore additional ultrason­ic investigation is necessary in the foreign body in the marginal zone, i.e. in ocular membranes or close to them. It helps to determine in­dividual size of the eye and define more exactly the localization of the foreign body as to the eye membrane, i.e. to determine whether it is inside or behind the eye. Skeleton-free roentgenography by Fogte is used to diagnose fine foreign bodies in the anterior part of the eye including nonmetallic ones (glass, stone).