Contact Lens Peripheral Ulcer: Diagnosis and Care

A contact lens peripheral ulcer is a small, round infiltrate with an overlying epithelial defect near the corneal edge in a person who wears soft lenses.

It is usually sterile, resolves within a week or two, and leaves little or no scar.

The challenge is to separate it from true microbial keratitis, which is rare but threatens vision.

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What Is a Contact Lens Peripheral Ulcer?

Doctors think the lesion is an immune reaction to bacterial antigens, such as Staphylococcus exotoxins and cell wall products, that collect on the lens and sit against the periphery of the cornea.

It is more frequent with extended wear and with lens contamination, and often occurs in the morning after sleeping in lenses (see contact lens overwear syndrome).

It is one of several corneal infiltrative events described in lens wearers.

Contact Lens Peripheral Ulcer: Typical Features

• Mild to moderate discomfort, redness, and tearing, usually worse after waking
• A single round infiltrate, below about 1.5 millimeters, located in the periphery or midperiphery of the cornea
• Overlying epithelial staining with a clear zone between the lesion and the limbus
• Little or no anterior chamber reaction, and no hypopyon
• Mild limbal or conjunctival injection in the sector near the lesion

Vision is usually normal.

How to Distinguish It From Microbial Keratitis

• Size and depth: microbial ulcers are larger, deeper, and often central, with dense infiltrates
• Pain: severe pain, photophobia, and reduced vision point toward infection
• Anterior chamber: cells and flare, or a hypopyon, indicate infection
• Course: infection progresses despite stopping the lens, while sterile lesions improve

When there is doubt, treat the lesion as infection and scrape it for culture (see contact lens microbial keratitis risk factors).

A diagnostic rule used by many clinicians is that a peripheral small lesion with minimal symptoms can be managed conservatively, while any central or large infiltrate gets cultured.

Management for Contact Lens Peripheral Ulcer

• Remove the lens and stop wear until the eye is clear
• Start a topical antibiotic, often a fluoroquinolone, as a precaution, four times daily
• Add a cycloplegic if there is photophobia
• Consider a mild topical steroid after the epithelium has healed and infection is excluded, though this is controversial
• Review in 24 to 48 hours, and again at one week

Expect healing over several days, and a scar is rare.

Discard the old lenses and the case, and advise on the use of fresh ones.

Contact Lens Peripheral Ulcer: Preventing Recurrence

• Avoid overnight wear, or limit it as far as possible
• Clean and replace the case every month, and use fresh solution each day
• Never use tap water, and wash the hands before handling lenses
• Replace the lenses on schedule, and consider daily disposables
• Treat blepharitis, which is a known risk factor (see blepharitis)

Patients may return to lens wear after complete healing and a clear review.

Counselling

Explain that most of these ulcers resolve, but that any new pain, redness, or reduced vision needs prompt review.

Stress that sleeping in lenses is the biggest modifiable risk.

Related Infiltrative Events

Contact lens wear can lead to other infiltrative events, and each has a typical picture.

• Contact lens-induced acute red eye: a painful, red eye that wakes the patient at night after sleeping in lenses, with multiple small infiltrates and a hazy cornea (see CLARE)
• Infiltrative keratitis: one or more small infiltrates with mild symptoms and an intact epithelium
• Asymptomatic infiltrates, found at routine examination in some wearers
• Microbial keratitis: a large, deep infiltrate with pain and an anterior chamber reaction

A careful examination at each stage guides the decision on cultures and treatment.

Why Staphylococcus Matters

Staphylococcal organisms colonize the lid margin and the lens, and their toxins bind to the corneal periphery, where the tear film is thin and the lens edge presses.

This explains why the same sector, often at the three and nine o’clock positions, may be affected again, and why lid hygiene is a helpful part of prevention (see staphylococcal marginal keratitis).

When to Refer

Refer a patient promptly if the infiltrate is larger than about 2 millimeters, if it is central, or if it fails to improve within two days.

Lesions that recur frequently also deserve a review of the lens type, the care regimen, and the lid margin.

Documentation Tips

Record the size of the infiltrate in millimeters, the distance from the limbus, the staining, and the anterior chamber findings, and photograph the lesion if possible.

At the follow-up visit, repeat the measurements, so that growth or healing is obvious.

Keep lenses that the patient wore for culture if the lesion looks suspicious, since the case and solution may yield the organism.

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References

1. Sweeney DF, Jalbert I, Covey M, et al. Clinical characterization of corneal infiltrative events observed with soft contact lens wear. Cornea. 2003;22:435-442.
2. Stapleton F, Keay L, Edwards K, et al. The incidence of contact lens-related microbial keratitis in Australia. Ophthalmology. 2008;115:1655-1662.
3. Efron N. Contact Lens Complications. 4th ed. Elsevier; 2018.
4. American Academy of Ophthalmology. Basic and Clinical Science Course, Section 8: External Disease and Cornea. AAO; current edition.