Contusions of the Eyeglobe

The clinical symptom-complex in the postcontusional period is rather diversiform and contains not only signs of the eyeglobe dam­age, but also changes of general health condition. Within first days after the trauma there is observed pain in the cranio-fascial area on the side of the injury, as well as headache, nausea, a slight syn­cope, complication of the convergence while reading.

One of the signs of the contusion of the eyeglobe is the mixed injection of vessels. It is little expressed during first hours after the trauma, increases within the first day and keeps at the same level for 3-4 days and gradually decreases by the end of the 1 st - be­ginning of the 2nd week.

Some clinical signs of the eyeglobe contusion are conditioned by different vascular failures. Intraocular haemorrhages occur.

Contusion of the eyeglobe may be accompanied with the change of intraocular pressure to both the side of increasing (re­active hypertension), and decreasing (postcontusion hypotension). Besides vascular failures, the cause of ophthalmotonus changes is disturbance of anatomic relationships in the field of the angle of the front camera and drainage system of the eye, as well as changes in the ciliary body leading both to increasing and de­creasing of its secretory function. The extent of injuries of the eye- globe tissues and their combinations are very miscellaneous. More often the tissues of the front department of the vascular tract: the iris (60%), the cornea (40%), the retina and the optic nerve (36%) are damaged.

Cornea. The most common injury to the cornea is the corneal abrasion. Here, the patient

experiences a sharp pain in the eye in the early morning usually on waking, sometimes many months after the initial injury. The cornea is to be examined carefully with the slitlamp biomicroscope. This problem of recurrence is a reason to treat these abrasions with some care and to provide the patient with a lubricating

ointment to be used at night for some time after the original injury has healed. Sometimes, recurrent abrasion results from a rare inherited disorder of the corneal epithelium. When a patient presents with a corneal abrasion, the eyelids are often swollen perhaps from rubbing and the distress and agitation can be considerable. Examination may be impossible without first instilling a drop of local anaesthetic.

These drops should never be continued as treatment because they could seriously delay the healing of the cornea.

Anterior Chamber. A small bleed into the anterior chamber of the eye is seen as a fluid level of blood inferiorly (“hyphaema”). This is a sign of potential problems because of the risk of secondary bleeding after two or three days. This risk is especially serious in children and the complication can lead to secondary glaucoma and at worst, the loss of the eye.The parents need to be warned about this if there is a hyphaema. Treatment is by strict rest with little or no head movement to avoid further bleeding and regular measurement of the intraocular pressure.

Iris. When confronted by a flying missile, the normal reaction is to attempt to close the eyelids and to rotate the eyes upward. This is the reason why the commonest point of impact is the lower temporal part of the eye and it is in this region of the iris that one is most likely to see peripheral iris tears (“iridodialysis”). When the eye is compressed the iris periphery is torn at its root, leaving a crescentic gap, which looks black, but through which the fundus and red reflex can be observed. Such an injury also provides an excellent view of the peripheral part of the lens and the zonular ligament

Contusion can result not in a tear of the iris root, but in a tangential splitting of the iris and ciliary body from the sclera producing recession of the angle of the anterior chamber; the appearance is often associated with secondary glaucoma, sometimes many years after the injury and is identified using the special contact lens known as the gonioscope. A sudden impact on the eye can also produce microscopic radial tears in the pupillary sphincter of the iris. This could be a subtle microscopic sign of previous injury when no other signs are present, or the damage might be more severe, resulting in persistent dilatation of the pupil (traumatic mydriasis). Unless the eye is examined, this widening of the pupil after injury can be mistaken for a third cranial nerve palsy.

Lens. Any severe contusion of the eye is liable to cause traumatic cataract(in rossette shaped pattern), but the lens might not become opaque for many years after the injury. The lens can also become subluxated (slightly displaced because of partial rupture of the zonular ligament) or even dislocated either anteriorly into the anterior chamber or posteriorly into the vitreous.

Vitreous. The vitreous can become displaced from its attachments around the processes of the ciliary body or around the optic disc after a contusion injury if it has not already undergone this change as part of the normal ageing process. The patient might be aware of something floating in front of the vision. More extensive floating black spots can indicate a vitreous haemorrhage caused by excessive vitreous traction on a retinal blood vessel. Although such haemorrhages usually clear completely in time, they tend to accompany more serious damage to the retina,which can only be fully revealed once clearing has taken place.

Retina. Bruising and oedema of the retina are seen as grey areas with scattered haemorrhages. The macular region is susceptible to oedema after contusion injuries, causing permanent damage to the reading vision. Just as tears can occur to

the peripheral iris, so a similar problem is seen in the peripheral retina. These crescent-shaped retinal dialyses are also most common in the lower temporal quadrant and their importance lies in the fact that they may lead to a detachment of the retina unless the tear is sealed by laser treatment. Any significant contusion injury of the eye requires a careful inspection of the peripheral retina.

Choroid. Tears in the choroid following contusion have a characteristic appearance. They are concentric with the disc and are seen as white crescents where the sclera is exposed. When near the macula, there is usually permanent damage to the central vision. They are also potential sites for choroidal neovascularisation.

Optic Nerve. A variable degree of optic atrophy can become apparent a few weeks after a contusion injury. Blunt injuries to the eye can cause bleeding into the optic nerve sheath or tearing of the tiny pial blood vessels that supply the nerve, both resulting in complete, irreversible loss of vision on the affected side. Attempts have been made to relieve the situation by emergency decompression of the optic nerve, nerve sheath fenestration, use of hyperbaric oxygen and highdose steroids. No treatment has shown a clear benefit except optic nerve decompression in specific circumstances.

Eye burns constitute 6-36% of all eye injuries. There are ther­mal and chemical burns.

Thermal burns are observed when burning metal, boiling liquid, and rarely flame get into the eye. In millitary actions thermal burns were often observed in pilots and members of a tank crew in com­bustion of petrol.

Isolated injury of the eyelids and eyes occurs rarely, usually it is combined with vast burns of the face and other parts of the body.

In mild burns of the conjunctiva manifested in its hyperemia and oedema, there are marked lacrimation, photophobia and blepha­rospasm. In severe cases some areas of the conjunctiva turn gray­ish, then they necrotize and are rejected baring the sclera.

In mild burns of the cornea, only epithelium is affected, white-grayish cloudings or erosions appear which later on disappear without traces. In severe cases all layers of the cornea are affect­ed; it turns white-grayish, becomes rough and loses sensitivity. It is accompanied by marked irritation of the eye, oedema of the eye­lids, narrowing of the lid slit, lacrimation and photophobia. It re­sults in opaque cicatrices, disturbing eye function.

Chemical burns are caused by acids or alkali and alkaline burns are much more dangerous and have a more severe course.

Acid in contact with the tissue causes coagulative necrosis, therefore its effect is limited by the area in contact with acid. Al­kali dissolves proteins causing colliquative necrosis and penetra­ting inside, it continues destruction. Therefore, the affections spreads even in several days after burn.

According to the severity of pathological changes there are burns of 4 degrees. The mildest, / degree is characterized by con­junctival hyperemia, superficial erosion on the cornea and mild oedema of the epithelium. The affection of the // degree is charac­terized by marked ischemia of the conjunctiva; the mucous mem­brane becomes gray, there are areas of opacity in the cornea, it becomes rough and loses sensitivity. In burn of the HI degree the cornea is diffusely turbid, necrotized and resembles frosted glass. Burn of the IV degree is distinguished by deep necrosis of the co­njunctiva and cornea, the latter becomes of porcelain color.

Considerable biochemical and trophic changes take place in eye tissues in burns. Besides, severe burns by alkali may lead to struc­tural change of organospecific antigens of the cornea and devel­opment of organism autosensitization. It is explained by the fact that in burns by alkali the pathological process is long (several months) with vast cicatreous process, adhesion of lids with eye­ball (symblepharon) and cicatreous shortening of the conjunctival vaults.

Treatment of burns is divided into first aid, treatment of fresh burns and treatment of burn consequences.

First aid in burns must be given immediately: plentiful washing out of the conjunctival cavity with water for 15-30 min depend­ing on the degree of severity.. In burns with alkali it is necessary to remove pieces of line thoroughly from the conjunctival vaults. In burns with acids it is indicated to irrigate the eye with neutral­izing solutions: 2-3% solution of sodium hydrocarbonate, 5% so­lution of thiosulfate. In injuries with alkali it is indicated to irri­gate the eye with 2-3% solution of acetic boric or citric acid. Then the eye is put disinfectant solutions (0,25% solution of levornyci-tin, 20% solution of sodium sulfacylum) and applied ointment (5% levomycitin, 1% tetracycline). Tetanus anatoxin and antitetanus serum by Bezredko should be given in burns of III-IV degree.

Treatment of fresh burns should be carried out at the in-patient department, a specialized department (a burn centre). It must be directed at creation of favourable conditions for regeneration of the damaged tissues as well as prophylaxis of infection. It is use- ful to wash out the eye profusely with nitrofurazone solution 1:5000. Hemodesis 3-5 ml is introduced under the conjunctiva and vaults daily for 6-7 days. There is also indicated subconjunctival intro­duction of "cocktail": autoserum, antibiotics, vasodilating drugs and anticoagulants. A beneficial effect is observed in using serum of burn reconvalescents by subconjunctival and intravenous injec­tions. To fight against infection and improve trophicity, regenera­tion of the eye tissue it is necessary to put drops of 20% sulfaceta­mide sodium, 1% solution of quinine hydrochloride, 5% solution of glucose, 0.01% solution of riboflavinum every hour. 5% metacylic ophthalmic ointment or 1% tetracycline ophthalmic ointment are put undei the eyelids. We also administer subconjunctival injections of antibiotics, desensiting remedies orally (dimedrolum, syprasti-num, pipolphen, tavegil).

In case of especially severe fresh burns (III-IV degree) it is nec­essary to perform urgent lamellar therapeutic keratoplasty by con­served donor's cornea. The necrotized conjunctiva is substituted for implant from the patient's labial mucous membrane (Demig's ope­ration) or autoconjuctiva.

After complete epithelization of the cornea corticosteroids are administered to diminish autosensitization and prevent obliteration of the newly formed vessels of the cornea. Obliteration of the ves­sels is also decreased by B-therapy with the help of ophthalmic B-applicators.

Because of severe burns gross leukoma or gross symblepharon is formed. Sometimes there may be complete adhesion of the eye­lids with eyeball (ankyloblepharon). Treatment of such severe out­comes requires special, sometimes many-staged surgical interven­tions aimed at elimination of symblepharon adhesions, renewal of conjunctival vault. In gross vascularized leukomas keratoprosthe-ses from alloplastic materials are implanted.

Date: 2015-02-03; view: 988