Ocular Burns - Causes, Symptoms, Evaluation, and Treatment

Introduction

Acute ocular burns might be considered an emergency of the eyes. Several variables influence the injury's severity. These variables include the violating substance, the duration of exposure, the affected surface area, and the impacted ocular tissues. Burns to the eye and ocular adnexa (include the eyelids, the conjunctival sac, the lacrimal drainage system, the lacrimal gland, and the orbital contents except for the eye and optic nerve) cause moderate to severe morbidity and may have long-term effects on eyesight and quality of life. The typical residual effects of more severe burns include acute and persistent pain, scarring with subsequent deformities, loss of protective adnexa function, and irreversible eyesight loss. In addition, persistent blindness raises the chance of subsequent accidents, depression, chronic illness, and other severe biopsychosocial problems.

What Are Ocular Burns?

Ocular burns are a serious condition that can occur after thermal or chemical burns and cause irreversible blindness. Acute and ongoing pain, scarring with eventual abnormalities, loss of protective adnexa function and permanent vision loss are common persistent symptoms of ocular burns. In addition, the risk of recurrent accidents, depression, chronic sickness, and other serious biopsychosocial issues increases with persistent blindness.

What Are the Causes of Ocular Burns?

The two main kinds of burns to the eye and ocular adnexa are:

1. Thermal Burns: Accidents involving fireworks, steam, boiling water, or molten metal can result in thermal burns (commonly aluminum). The eyelids' skin may sustain most of the damage from thermal burns because of the blink reflex and the ocular adnexa's defensive function. Due to the short contact duration, direct heat burns to the ocular surface often result in superficial harm. Hot water, hot frying oil, curling irons, and a flame, such as an explosion or a fire, are common sources of thermal ocular burns. This type of thermal burn can be anticipated.

2. Chemical Burns: Acidic or alkaline substances can both result in chemical burns.

• Alkaline Substances: Alkaline substances like ammonium hydroxide, used in fertilization, sodium hydroxide (caustic soda), used in pipe cleaning; and calcium hydroxide (a component of lime plaster and cement). These substances may quickly permeate cell membranes and reach the anterior chamber because they combine hydrophilic and lipophilic qualities, which makes them highly harmful. Alkali damage happens when hydroxyl ions combine, leading to cell death and membrane saponification, as well as the rupture of the extracellular matrix.

• Acidic Substances: Acidic substances include hydrochloric acid (used in swimming pools), sulphuric acid, which is found in automobile batteries, and sulfurous acid, which is present in certain bleaches and can cause harmful effects. Acid binds to collagen and shrinks the fibrils. Because numerous corneal proteins bind to acids and serve as a chemical buffer, acids often cause less harm than alkalis. Furthermore, coagulated tissue serves as a barrier to other acid penetration.

What Are the Symptoms of Ocular Burn?

While the eyes have a cleansing mechanism, they are a delicate area of the body that may easily be hurt and have lifelong issues. Due to this, ocular burns are ophthalmological emergencies that require immediate medical attention. Depending on the material sprayed into the eyes, an ocular burn may cause the following symptoms:

• Burning and stinging sensations.

• Redness around the eyes or in the eyes.

• Eyelid swelling.

• Cloudy, double, blurry, or foggy vision.

• Watery eyes.

• Difficulty in opening or closing the eye.

How to Evaluate Ocular Burn Conditions?

The history, physical examination, and clinical suspicion of further injuries should be the basis for further imaging. Computed tomography (CT) imaging of the orbits may be useful if an intraocular foreign body is suspected due to the cause of the damage, like a blast or injury. The degree of affected ocular surface and related structures can be assessed after the eyes and related structures have received adequate hydration. The pH (potential of hydrogen) of the ocular surface reaches neutral (7.0 to 7.2) by litmus paper assay. If feasible, visual accuracy can also be evaluated.

Although, blepharospasm (abnormal contraction of the eyelid muscles) due to pain from exposed superficial ocular nerves may be severe and restrict examination. Before biomicroscopy, applying a topical eye anesthetic (slit lamp evaluation) may be essential. Staining the eye with a substance such as sodium fluorescein is necessary to measure the affected surface area.

How to Manage Ocular Burns?

Sterile irrigating or amphoteric solutions can be used for the first ocular lavage. The primary choice in the prehospital situation will be tap water. Due to its relative hypotonicity to the cornea, tap water should be utilized. However, the fundamental conditions for an emergency irrigation solution are satisfied by tap water.

Irrigation: Ocular irrigation must continue until the patient is admitted to the hospital, until the pH of the eye's surface is between 7.0 and 7.2. For minor injuries, 2 liters of irrigation may be needed. For more serious injuries, up to 10 liters for about 30 minutes may be needed. For effective cleaning of severe injuries, 2 to 4 hours of continuous irrigation may be needed. Lactated Ringers, balanced salt solution, or 0.9 % sodium chloride are effective irrigants.

What Are the Treatments for Ocular Burns?

1. Initial Treatments:

• Preservative-free artificial tears and topical antibiotic ointment may be adequate for minor wounds.

• Complications such as ocular surface exposure from adnexal scarring, corneal or stromal thinning, and increased intraocular pressure necessitate frequent monitoring.

• Steroids used topically are used to reduce inflammation. To relieve discomfort, topical cycloplegic medications might be helpful.

• Erythromycin ophthalmic ointment is a suitable option for initial treatment since it is easily accessible, well-tolerated, and has a prophylactic agent.

• To aid in wound repair, doctors frequently administer systemic tetracyclines (Doxycycline 20 to 50 mg per oral twice daily) and vitamin C (1,000 mg PO daily).

2. Complex Treatments: More complex treatments, such as topical biologics, like autologous serum and platelet-rich plasma drops, will be needed for more severe burns. Bandage contact lenses are effective for defects in the corneal epithelium and are a great way to control discomfort caused by exposed corneal nerves. It is essential to administer antibiotic prophylaxis against Pseudomonas when wounds are bandaged with contact lenses. The higher degree of burn often requires early amniotic membrane transplantation (applying a piece of amniotic membrane or graft to the eye's surface). In situations with severe scleral melting or ischemia, tenonplasty (a plastic operation in which vital connective tissue of the orbit is used) can effectively encourage re-epithelialization.

Conclusion

Injury prevention at work involves several factors, including using sufficient PPE (personal protective equipment) while handling chemicals. Periodic hazardous materials training, which includes decontamination procedures, helps prevent such injuries. Workers must know where on-site decontamination resources are located and how to use them during exposure.