Corneal Ulceration and Ulcerative Keratitis in Emergency Medicine Clinical Presentation

Numerous symptoms can help determine the diagnosis of keratitis.

Current symptoms

• Erythema of eyelid and conjunctiva
• Mucopurulent discharge from eye
• Foreign body sensation
• Blurred vision
• Light sensitivity
• Pain

Medication and contact lens use

• Contact lens use
• Type of contact lens (soft, hard, extended wear)
• Type of contact lens solution
• Contact lens hygiene
• Current ocular medications, especially steroids

Past medical history

• History of ocular disease, eye surgery, or both
• Diabetes mellitus
• History of HIV or other immunodeficiency disorder
• Exposure to sulphur mustard^[5]
• Collagen vascular disease (rheumatoid arthritis [RA])

Social history

Smoking history is important.

Inquiry about the dietary habits of a patient with a corneal ulcer is important because vitamin A deficiency is associated with corneal ulcer formation. Inadequate vitamin A can occur in a patient with an intentional diet deprivation or unintentional deprivation found in young children and pregnant women from Africa and Southeast Asia. Secondary vitamin A deficiency may be found in a patient with celiac disease, sprue, cystic fibrosis, pancreatic disease, duodenal bypass, congenital partial obstruction of the jejunum, obstruction of the bile ducts, giardiasis, and cirrhosis.

The physical examination should be thorough, with additional focus on the eye examination.^[6] Visual acuity, gross examination of the eyelids, surface of the eye, pupils, extraocular muscles, and fundi, should be performed and documented. A slit lamp examination and ocular pressure measurements should also be obtained.

Visual function is variably affected, depending on the location of the ulcer and whether associated corneal and uveal inflammation is present. Obtain visual acuities on all patients with ocular complaints.

Examination of the lids and the conjunctiva may reveal associated inflammation in these locations.

The eye is typically erythematous, and ciliary injection is often present. Pupillary constriction is usually present secondary to ciliary spasm and iritis.

Purulent exudate may be seen in the conjunctival sac and on the surface of the ulcer, and infiltration of the stroma may result in a creamy opacity of the cornea. The ulcer often is round or oval, and the border generally is demarcated sharply, with the base appearing ragged and gray.

Slit lamp examination may reveal findings of iritis, and hypopyon may be present. Hypopyon is an accumulation of inflammatory cells in the anterior chamber that produces a layered meniscus in the inferior anterior chamber.

Fluorescein staining may reveal the characteristic dendritic ulcer of herpes simplex virus infection.

A Wood lamp may be useful because the ulcer associated with P aeruginosa fluoresces in ultraviolet light.

Viral infections

Herpes simplex virus (HSV) infection is the most common cause of corneal ulcer in the United States. Although not always present, the classic finding in HSV infection is a branching dendritic ulcer.

Infection with HSV may interfere with corneal sensation, resulting in corneal anesthesia.

Varicella-zoster virus (VZV) can cause a corneal ulcer. Although corneal involvement can occur in varicella (chickenpox), it is uncommon and typically benign. The form of zoster (shingles) involving the ophthalmic branch of the trigeminal nerve is a more common corneal infection caused by VZV.

When herpetic eruption occurs along the nose, the nasociliary branch of the ophthalmic nerve is involved, indicating that corneal involvement is likely. This is known as the Hutchinson sign.

The dendritic pattern seen in HSV infection is not seen with zoster infection, although pseudodendrites, which only vaguely resemble true dendrites, may be present. Loss of corneal sensation is a prominent feature of zoster infection.

In contrast to the usual benign course in varicella and HSV, corneal complications in ophthalmic zoster can be severe and blinding.

Superficial punctate keratitis is characterized by destruction of pinpoint areas in the outer layer of the corneal epithelium is associated with adenoviruses.

Bacterial infections

Numerous bacteria have been reported to cause corneal ulcer, although staphylococcal species, P aeruginosa, Streptococcus pneumoniae, and Moraxella species are reportedly the most common causes in the United States.

Clinical characteristics of corneal ulcers caused by various bacteria are not sufficiently distinct to determine the causal bacterial agent, although a corneal ulcer having a bluish or green mucopurulent discharge is almost pathognomonic for P aeruginosa.

Most corneal ulcers are centered, but some occur at the periphery of the cornea (ie, marginal ulcers).

Although the location of the ulcer does not correlate well with the causative organism, a marginal ulcer is more likely to occur as a result of staphylococcal blepharoconjunctivitis. This ulcer is not due to direct bacterial infection but rather is an inflammatory reaction to staphylococcal bacterial antigens and toxins. The ulcer usually is self-limited and lasts from 7-10 days, but it is likely to recur unless the underlying blepharoconjunctivitis is treated.

Fungal infections

Fungal ulcers are caused by Candida, Fusarium, Aspergillus, Penicillium,Cephalosporium, and mycosis fungoides species.

• Acanthamoeba keratitis
• Peripheral ulcerative keratitis, associated with rheumatoid arthritis, relapsing polychondritis, and Wegener granulomatosis
• Photokeratitis (snowblindness) is caused by excess exposure to UV light. This can occur with sunlight, suntanning lamps, or a welding arc.
• Sulphur mustard chemical keratitis