Eye burn are acute traumatic damage to the eyeball, the protective and accessory apparatus of the eye by aggressive chemicals or physical factors. Eye burn is accompanied by sharp pain, loss of vision, lacrimation, swelling of the eyelids and conjunctiva, the appearance of blisters on the skin. Diagnosis of an eye burn is carried out taking into account the data of anamnesis and external examination; additionally, it may include measurement of intraocular pressure, biomicroscopy, ophthalmoscopy. An eye burn requires immediate first aid – copious washing of the conjunctival cavity, instillation of an anesthetic solution, laying an antibacterial ointment behind the eyelid and delivering the patient to the hospital, where the question of further tactics is being decided.
Eye burns account for 5 to 15% of all eye injuries in ophthalmology. Of these, 65-75% of cases occur at work, the rest – in everyday life. The largest group of burns (60-80%) is eye damage by chemical agents (alkalis, acids, lime, etc.); thermal burns by flame, steam, boiling water, and molten metal particles are the next most common. Less often, eye burns develop under the influence of infrared rays, ultraviolet, ionizing radiation. First of all, the skin of the eyelids and conjunctiva suffer from eye burns, but the lacrimal pathways, cornea, deep structures of the anterior and posterior parts of the eye can also be traumatized.
More than 40% of chemical burns are caused by the ingress of various alkalis into the eye (ammonia, caustic soda, slaked lime, ethyl alcohol, caustic potassium, etc.), another 10% – contact with concentrated acids (acetic, sulfuric, hydrochloric, etc.). In other cases, eye burns are caused by careless handling of construction paints and varnishes, household aerosols, personal self-defense equipment (spray cans, gas pistols), eyelash dye, poisonous plants (hogweed, etc.), herbicides, insecticides, etc. Erroneous instillation into the eyes of solutions not intended for these purposes (ear drops, alcohol tinctures) can also lead to burns.
When alkalis get into the eyes, colliquational necrosis develops, characterized by hydrolysis of cell membranes, cell death, and enzymatic destruction of tissues. The depth and size of the resulting necrosis usually exceed the size of the zone of direct contact with the aggressive agent, so reliable information about the severity of the damage can be obtained only after 48-72 hours.
Exposure to the eye with acid leads to coagulation necrosis – denaturation of cellular proteins and the formation of a scab, pathological changes under which may be poorly expressed or absent. Further damage to the eye caused by acid burns is associated with inflammation caused by a toxic reaction and the addition of a secondary infection.
Thermal burns are caused by exposure to the eyes with high–temperature agents – boiling water, steam, hot fat, flame, molten metal particles, incendiary and flammable mixtures (firecrackers, fireworks, etc.). Thermal eye injuries are often combined with burns of the skin. The nature of the lesion in thermal eye burn is coagulation necrosis.
Radiation burns include damage to the eye apparatus by infrared or ultraviolet rays, ionizing radiation. Eye burns from infrared rays are found in metallurgists, people working with laser sources, etc. In this case, damage to the appendages of the eye and the anterior part of the eyeball occurs more often; in rare cases, infrared rays may penetrate into the fundus with the development of edema and subsequent dystrophic changes in the retina. Damage to the eyes by ionizing radiation usually occurs when in contact with radioactive dust or other sources of radiation. Eye burns associated with exposure to sunlight can occur in conditions where ultraviolet rays are slightly delayed by the atmosphere, for example, in the mountains: such an eye lesion is called snow ophthalmia (mountain or snow blindness). Photophthalmies associated with the radiation of electrical sources (electric welding, the use of quartz lamps, etc.) are called electrophthalmia.
Thus, taking into account the etiology, eye burns can be chemical, thermal, radiation and combined.
According to the depth of the damaging effect on the tissues , there are four degrees of eye burns:
- Grade I (mild) is characterized by hyperemia of the skin of the eyelid and conjunctiva; edema and superficial erosions of the cornea, which are determined during an instillation test with fluorescein. The criterion of a mild degree of eye burn is the complete disappearance of these lesions.
- Grade II (moderate severity) is manifested by damage to the surface layers of the eyelid skin, edema and shallow necrosis of the conjunctiva, damage to the epithelium and corneal stroma, due to which the surface of the cornea becomes uneven and grayish-cloudy. Burn blisters form on the skin of the eyelids.
- Grade III (severe) is characterized by necrosis of the conjunctiva and underlying tissues – eyelids, cartilage, sclera. With a severe burn of the eye, the conjunctiva takes the form of a yellowish or grayish-white scab with a matte surface. The cornea becomes cloudy, its surface becomes dry. Iridocyclitis and cataracts may develop. Rejection of the scab is accompanied by scarring of defects in the mucous membrane of the eye and cornea. The damage affects no more than 50% of the surface of the eyeball.
- Grade IV (especially severe) occurs with deep necrosis or charring of not only the conjunctiva, but also the sclera. The cornea, due to the full depth of the lesion, becomes like an opaque porcelain-white plate. The development of severe uveitis, cataracts and secondary glaucoma is typical; corneal perforation is possible.
Depending on the localization, there are burns of the eyelids and the ocular region; burns of the conjunctival sac and cornea; burns causing rupture and destruction of the eyeball; burns of other parts and the accessory apparatus of the eye.
The development of pathomorphological changes in eye burns allows us to distinguish 4 stages of burn injury:
- The first stage of eye burn lasts up to 2 days. During this period, tissue necrobiosis rapidly increases, hydration and swelling of the cornea develops, dissociation (decay) of protein-polysaccharide complexes occurs.
- During the second stage of eye burn, lasting from 2 to 18 days, fibrinoid swelling of the cornea and pronounced trophic disorders develop.
- The third stage of eye burn is characterized by trophic disorders, tissue hypoxia and corneal neovascularization. This process takes 2-3 months.
- The fourth stage of eye burn can last up to several years. At this time, scarring processes are underway, the synthesis of collagen proteins by corneal cells is enhanced.
Assessment of the depth and extent of the lesion in the first hours after the eye burn is very difficult. The severity of an eye burn depends on the concentration and time of exposure to the damaging factor, as well as the speed of completeness of first aid. The prognosis for the preservation of visual function in severe and especially severe eye burns is unfavorable.
Symptoms of eye burn
With a mild burn, there is a sharp pain in the affected eye, redness and moderate swelling of tissues, a feeling of foreign body ingress, blurred vision. When exposed to thermal agents, reflex closure of the eye slit occurs, so the lesion can be limited only to the tissues of the eyelids. In case of contact with the flame, the eyelashes burn, in the future, incorrect growth of eyelashes may be noted – trichiasis.
Severe burns of the eye lead to necrosis of the conjunctiva and exposure of the sclera. In this case, an ulcerative defect is formed, which subsequently scars, forming a fusion between the eyelid and the eyeball. With corneal burns, lacrimation, photophobia, blepharospasm are noted; in severe cases, neurotrophic keratitis, corneal opacity. Depending on the severity of the eye burn, changes in visual function may manifest as a slight decrease in vision or its complete loss.
When the tissues of the iris and ciliary body are affected, iritis and iridocyclitis develop. With severe eye burns, the vitreous body and lens become cloudy, the vascular membrane and retina are damaged. A complication of deep eye burns is the development of secondary glaucoma. In case of infection of the eye tissues, endophthalmitis and panophthalmitis occur. Deep chemical burns lead to perforation of the cornea and death of the eye.
Eye burns can be combined with burns of other parts of the face and body.
Eye burns are diagnosed according to anamnesis and clinical picture. If burn damage to the eye is detected, immediate emergency care is necessary, therefore special ophthalmological examinations are not carried out in the acute period.
In the future, to assess the degree of damage, an external examination of the eyes is carried out with the help of eyelid lifts, determination of visual acuity, measurement of intraocular pressure, ophthalmoscopy, biomicroscopy with fluorescein staining to identify ulcerative corneal defects and other studies according to indications.
First aid for eye burns should be provided on the spot; further hospitalization of the victim in an ophthalmological hospital is necessary.
Urgent measures for eye burns are copious jet washing of the conjunctival cavity with saline solution or water. Independent use of neutralizing solutions is not recommended due to the possible unpredictable effect of reaction products on damaged tissues. In the first hours after the eye burn, the lacrimal tracts are washed, the embedded foreign bodies are removed from the conjunctiva and cornea. Drops are instilled into the conjunctival cavity or ointments of local anesthetic action are laid. The administration of tetanus serum to the victim is shown.
In the hospital, patients with eye burns are prescribed instillations into the eye of cytoplegic agents (atropine, scopolamine): they allow you to reduce pain and the likelihood of adhesions. In order to prevent infection, eye ointments and drops containing antibiotics (tetracycline, levomycetin, ciprofloxacin), NSAIDs are used. In case of eye burns, it is advisable to use tear fluid substitutes. Intramuscular and parabulbar injections of antioxidants (methylethylpyridinol) are prescribed. To stimulate the regeneration of the cornea, eye gels (dialysate from the blood of dairy calves or dexpanthenol) are placed behind the eyelid. With increased intraocular pressure, local antihypertensive drugs (betaxolol, dorzolamide) are prescribed. In severe degrees of eye burns, the use of glucocorticoids (dexamethasone, betamethasone, etc.) in the form of parabulbar or subconjunctival injections is indicated.
Of the non-drug methods for eye burns, physiotherapy and eyelid massage are used.
Surgical tactics for eye burns are highly variable and are determined by the nature and degree of damage to the eye tissues. If chemicals get into the anterior chamber of the eye, it is necessary to perform corneal paracentesis and remove the penetrated substances.
If there is a threat of eye loss in the early stages after an eye burn, surgical interventions can be performed on the eyelids or eyeball – necrectomy of the conjunctiva and cornea, vitrectomy, conjunctival cavity plastic surgery, early keratoplasty, etc.
In the future, it may be necessary to perform plastic surgery on the eyelids – correction of inversion or inversion of the eyelid, elimination of ptosis, restoration of eyelashes with trichiasis, surgical treatment of post-burn cataracts, etc. With the formation of corneal scars in the delayed period, layer-by-layer or through keratoplasty is performed; with the development of secondary glaucoma, anti-glaucomatous operations are performed.
Prognosis and prevention
The prognosis for eye burns is determined by the nature and severity of the injury, the timing of specialized care, and the correctness of drug therapy. The outcome of severe eye burns, as a rule, is entropion, the formation of a cataract, overgrowth of the conjunctival cavity, atrophy of the eyeball, significant degrees of decrease in visual function.
According to experts, about 90% of cases of eye burns can be prevented. Therefore, the prevention of eye burns, first of all, requires compliance with safety regulations when handling chemical and flammable substances, household chemicals; the use of protective glasses with light filters. Patients with eye burns need to be monitored by an ophthalmologist for at least 1 year after the injury.