The biomechanics of contusion injuries of the eyeball is quite complicated. Under the influence of external force (inflicted blow), the eyeball, despite the fact that its contents are resistant to compression, is deformed. At the same time, intraocular pressure rises, reaching very high values (up to 80 mm Hg. Art. And more), which is accompanied by rupture of various tissues, and then rapidly decreases to the initial level. As a result, under the influence of mechanical deformation of the capsule of the eye and sharp changes in intraocular pressure, changes occur associated with compression, stretching, and dislocation of the eye tissue.
One of the earliest signs of concussion in most patients is an injection of the eyeball, which increases in the following days. The expansion of the superficial vascular network occurs due to the vasomotor reaction of the vascular system of the eye to mechanical injury and can persist for a certain time.
The degree of contusion damage to the tissues of the eyeball and their combinations are very diverse. Most often, simultaneous damage to several structures at once is observed. So, a strong crush of the eyelids, severe swelling and local chemosis of the conjunctiva, as a rule, are combined with subconjunctival ruptures of the sclera. Medium and severe concussions are often manifested by hemorrhages in various structures of the eye: under the conjunctiva, in the anterior chamber, the lens lens (retrolental) space, in the retina. Intraocular vitreous hemorrhages often occur when the vascular tract is damaged: the iris, ciliary body, choroid. A thorough initial examination allows you to assess the degree of damage and develop optimal treatment tactics.
Corneal lesions
The most common form of corneal damage is erosion, which can be very diverse in size and depth. Superficial and small erosion, as a rule, epithelize in the first 3 days, more extensive – within a week. Clinical erosion of the cornea is manifested by photophobia, lacrimation, blepharospasm, and a feeling of a foreign body. With a central location of
erosion, patients note blurred vision, with a stromal lesion – a decrease in visual acuity. The outcome of stromal lesions can be persistent clouding of the cornea in the form of various sizes and shapes (round, ethmoid, spindle-shaped) opacities.
Treatment. Prescribe disinfectant drops, ointments, corneal regeneration stimulants (cornegel, solcoseryl), methylene blue with quinine; in case of severe blepharospasm, perivasal blockade of 5 ml of a 0.5% lidocaine solution along the superficial temporal artery is performed. A bandage is applied to the injured eye. Be sure to introduce tetanus toxoid. Damage to the endothelium is less common, it leads to a disk-shaped edema of the stroma in the deep layers. Penetration of edematous fluid into the middle and anterior layers of the stroma causes clouding of the cornea in the form of stripes or lattice, which gradually (within a few days or weeks) disappears, but after significant damage to the posterior epithelium (endothelium), ruptures of the posterior border membrane and stromal fibers, a scar may remain clouding of the cornea. Almost never with shell shocks, a complete rupture of the cornea (in full thickness) occurs, which is explained by its considerable strength and elasticity. Severe contusion may be accompanied by corneal stroma imbibition with a blood pigment – hematocornea, which occurs as a result of rupture of the posterior epithelium and posterior border membrane in the presence of hemorrhage in the anterior chamber and increased intraocular pressure. Turbidity of a reddish-brown color subsequently becomes greenish-yellow, and then gray. Corneal transparency is restored very slowly and not always completely. Treatment. First, fibrinolysin, hemase, physiotherapeutic procedures and antihypertensive drugs are prescribed to resolve turbidity. At a later date, if there is intense turbidity, surgical treatment (corneal transplantation) is possible.
Scleral damage
Clinically, contusion damage to the sclera is manifested by its rupture (usually of a lunate shape) in the weakest section – the upper outer or upper inner quadrant 3-4 mm from the limb and concentrically to it. Rupture of the sclera may be accompanied by a rupture of the conjunctiva (in this case, the iris, ciliary body, lens and vitreous body can fall into the wound) or not be accompanied by it (subconjunctival rupture).
The main symptoms of subconjunctival rupture of the sclera are limited chemosis of the conjunctiva and hyphema (hemorrhage into the anterior chamber), hemophthalmus (hemorrhage into the vitreous body), changes in the depth of the anterior chamber, hemorrhage near the limb, hypotension, prolapse under the conjunctiva of the lens, iris, and pupil rupture.
Diagnosis is difficult as a result of edema and subconjunctival hemorrhage, which may cover scleral rupture. To clarify the diagnosis, a diaphanoscopic test is used (L.F. Linnik, 1964): when a scleral lamp illuminates through the cornea and pupil, a red glow is determined at the site of rupture of the sclera. A symptom of a pain point also helps diagnose (F.V. Pripechek, 1968): after epibulbar anesthesia with 0.25% alkaine solution, pressing a glass rod on the area of the gap causes sharp pain, if there is no gap, the pain does not appear. Rupture of the sclera most often occurs along the limb, and in severe cases, the defect continues under the rectus muscles of the eyeball up to the optic nerve. At the rupture, the ciliary body exits; prolapse of the lens, vitreous body and retina is also possible. Indirect signs indicate a rupture of the sclera: decreased vision, severe hypotension. Treatment. In case of suspicion of rupture of the sclera, it is mandatory to conduct a wound audit, suturing of the sclera wound with the reduction or excision (when crushing) of the fallen inner shells.