Trauma



Trauma





Ocular trauma is a leading cause of blindness in developed countries. Trauma may occur in industrial settings, during sports activities, or at home. Most patients affected are young males, and the majority of cases are anterior segment injuries.


CHEMICAL BURNS

An ocular chemical burn is an emergency requiring immediate irrigation with water or saline solution at the site of injury for at least 30 minutes. Mechanical removal of foreign particles should also be performed. These actions should be repeated at the emergency room after quickly checking the pH of the tears, even before taking a detailed history or performing a complete eye examination.

If initial evaluation shows potentially life-threatening respiratory or gastrointestinal involvement, these conditions should be attended to first.


Etiology

• Alkali: Examples include sodium hydroxide (lye), calcium hydroxide (lime, cement, and plaster), and ammonia.

• Acids: sulfuric acid (battery fluid)

• Mace (chloroacetophenone) and teargas

• Organic solvents

• Detergents



Signs

• Mild to moderate

▪ Burns and edema of the eyelid

▪ Conjunctival injection, chemosis, abrasion

▪ Punctate or large epithelial defects on the cornea (Fig. 11-1A)

▪ Mild anterior chamber activity

• Severe

▪ Burns of the skin of the eyelids

▪ Chemosis, conjunctival necrosis, conjunctival ischemia (sludging or absence of blood flow through conjunctival vessels) (Fig. 11-1B-E, eFig. 11-1B and C)

▪ Scleral/limbal ischemia

▪ Significant anterior chamber activity

▪ Corneal epithelial defects, edema, or melting (Fig. 11-1F)


▪ Poor or no view of the anterior chamber because of corneal haze (Fig. 11-1G, eFig. 11-1G)

▪ Intraocular pressure (IOP) may be low, normal, or elevated in acute stages.

▪ The degree of limbal ischemia and corneal haziness carries prognostic importance.




Prognosis

• Dismal to excellent, depending on the severity of the injury (Fig. 11-1H, eFig. 11-1H). In general, alkaline substances cause the most severe injuries because they penetrate ocular tissues easily.







FIGURE 11-1. Chemical burn. A. A mild acid injury caused a large corneal abrasion, which has been stained with yellow fluorescein dye. There is minimal to no conjunctival blanching, and the cornea is essentially clear. Mild chemical burns generally resolve without serious consequences. B. A sulfuric acid injury occurred to this patient’s right eye. There is a large central and inferior corneal epithelial defect and mild inferior conjunctival blanching.







FIGURE 11-1. (continued) C. This eye withstood a battery acid (sulfuric acid) injury. There is moderate conjunctival blanching and mucus adherent to the conjunctiva and cornea. D. The left eye of the patient seen in B has a much more extensive sulfuric acid injury. The epithelium is necrotic and has already sloughed off of the superior cornea. There is extensive conjunctival and scleral blanching inferiorly and nasally.







FIGURE 11-1. (continued) E. High-magnification view of the eye seen in D demonstrating ischemia of the conjunctiva and sclera. There is segmentation of the red blood cells, indicating lack of blood flow. The greater the degree of ischemia, the worse is the prognosis. F. A severe lye (sodium hydroxide) injury caused extensive ischemic damage in the lower two-thirds of the eye. The cornea has undergone necrosis centrally, leading to a perforation requiring an emergency corneal transplant. This alkali injury eventually resulted in enucleation.







FIGURE 11-1. (continued) G. Twelve days after a severe alkali injury, the conjunctiva and sclera remain blanched, and the cornea is opaque. There has been no reepithelialization of the damaged cornea or conjunctiva. H. Many years after a severe chemical burn, the cornea remains totally scarred and vascularized.



THERMAL AND ELECTRICAL BURNS


THERMAL BURNS

Thermal burns can be mild to severe and can occur at any age. Cigarette burns are not uncommon in small children, whose eyes may be at hand level of a person holding a cigarette.


Etiology

• Curling irons

• Cigarettes, especially children

• Flames

• Hot liquids

• Molten metals



Signs

• Thermal burns on skin of eyelids

• Conjunctival injection, chemosis, epithelial defects (eFig. 11-2A1 and 2)

• Punctate or large epithelial defects on cornea

• A white area of cauterized epithelium (Fig. 11-2A)

• In severe cases

▪ Anterior chamber reaction

▪ Corneal haze and edema

▪ Limbal or scleral ischemia, corneal or scleral perforation (Fig. 11-2B)




Prognosis

• Depends on the severity of the injury, especially the exact cause of the burn and duration of contact. Short-contact burns, such as those from curling irons and cigarettes, have an excellent prognosis. Molten metal that adheres to the cornea causes a much more substantial injury. Eyelid damage can cause exposure problems and long-term difficulties with corneal healing.







FIGURE 11-2. Thermal injury. A. A curling iron briefly touched this cornea, causing coagulation of the corneal epithelium and turning it white. It can be removed mechanically or it will slough off naturally. Generally, these eyes recover without sequelae because the length of time the heat is in contact with the cornea is minimal. Electrical injury. B. An electrical injury caused a localized area of scleral melt with uveal prolapse. Additionally, the electrical injury produced necrosis of a large portion of upper eyelid tissue, resulting in severe exposure. The eye was treated with a scleral patch graft and eyelid skin grafting.



ELECTRICAL BURNS

Ocular electrical burns usually result from electrical injuries to the head or a lightning strike. In addition to corneal and scleral burns, they can cause acute uveitis. The lens is frequently involved, and cataracts may develop months to years later. Eyelid damage can cause exposure problems and long-term difficulties with corneal healing.


ULTRAVIOLET KERATOPATHY (ARC WELDER FLASH)

Severe, painful punctate keratopathy can result hours after exposure to significant levels of ultraviolet light.


Etiology

• Usually caused by welding or using a sunlamp without proper protective eyewear. Milder forms can also be seen in patients with significant sun exposure, such as after a day at the beach or after skiing.



Signs

• Spasm of eyelids in severe cases

• Punctate epithelial erosions, especially in the interpalpebral regions (Fig. 11-3)

• Eyelid edema, conjunctival hyperemia




Prognosis

• Typically excellent







FIGURE 11-3. Welder flash. Significant central punctate epitheliopathy is present in this patient 6 hours after welding without adequate eye protection. (Courtesy of Irving Raber, MD.)



CORNEAL ABRASION

Corneal abrasions result from corneal surface trauma that causes removal of a portion of the epithelial layer.


Etiology

• Mechanical trauma (e.g., fingernail, paper edge, tree branch)

• Chemical injuries, medicamentosa keratitis

• Foreign body

• Contact lens

• Misdirected eyelashes

• Neurotrophic or exposure keratopathy

• Iatrogenic (e.g., after removal of corneal sutures, epithelial debridement)



Signs

• Epithelial defect that may be detected grossly or at the slit lamp. It is easily seen with fluorescein dye using cobalt blue light (Fig. 11-4, eFig. 11-4A1 and 2).

Oct 13, 2019 | Posted by in OPHTHALMOLOGY | Comments Off on Trauma
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