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Contact Lens Strategies Following CLARE
BY GREGORY J. NIXON, OD, FAAO
Contact lens-induced acute red eye (CLARE) is an inflammatory condition of the cornea and conjunctiva. While various etiologies of CLARE often present with similar symptoms, the presenting ocular signs can help differentiate the likely initiating cause. Evaluating these signs can help establish a long-term contact lens management plan that can return CLARE patients to successful lens wear and decrease recurrent inflammatory episodes.
The biochemical triggers resulting in CLARE include corneal hypoxia, solution toxicity/hyper-sensitivity, bacterial hypersensitivity, or toxicity from entrapped post-lens tear debris. There can also be mechanical triggers from a poor-fitting or adherent contact lens, often a result of overnight wear. Regardless, the physiological response results in conjunctival injection, corneal edema, corneal infiltrates, and overlying superficial punctate keratitis. However, the location of these findings can lead you to the inciting cause. For example:
• Patients suffering from hypoxia often have presenting signs that are worse in the superior cornea from the added oxygen-blocking effect of the upper lid. Additionally, these patients often have significant pannus or neovascularization.
• Bacterial hypersensitivity can result from a contaminated lens that is not disinfected or replaced properly or from bacterial over growth in the tear film secondary to blepharitis or other ocular surface disease. These contaminants accumulate in the tear prism creating an inflammatory reaction in the inferior aspect of the cornea, often with corneal infiltration at the 4 o'clock and 8 o'clock positions. Additionally, phlyctenule formation is evidence of bacterial hypersensitivity.
• Adherent lenses cause me chanically induced edema on the paralimbal conjunctiva as well as a stagnant post-lens tear film filled with metabolic waste products that can induce diffuse toxic corneal edema, infiltration, and epithelial compromise.
Long-Term Management Clues
The initial treatment plan for most cases of CLARE is temporary cessation of lens wear and pharmaceutical intervention to aid recovery. However, additional clinical decision-making occurs after the cornea is healed and the patient is ready to return to lens wear. Determining the most appropriate lens and care system for patients are key elements to avoid future recurrences. For example:
• Patients who have hypoxia need a greater amount of oxygen within their corneal tissues to maintain adequate ocular health. Fit these patients in a silicone hydrogel lens for daily wear only. Further, instruct these patients to have one to two hours of non-lens wear during waking hours.
• While bacterial hypersensitivity patients should improve lid hygiene and lens care compliance, it is also important to maximize lens compatibility with tear film chemistry to prevent lens deposition that can contaminate the lens. Fit protein depositors in silicone hydrogels and muco-lipid depositors in hydrogel lenses to minimize lens surface deposits.
• If a lens material switch isn't effective itself, switch to hydrogen peroxide-based disinfection or use a more frequently replaced lens. Daily disposables eliminate lens contamination completely.
Improving your diagnosis of CLARE can help reduce recurrences and allow healthy contact lens wear for these patients. In a future column I will provide an overview of the pharmacological management of CLARE. CLS
Dr. Nixon is an associate professor of clinical optometry and the extern coordinator at The Ohio University College of Optometry. He is also in a group private practice in Westerville, Ohio. He is on the Allergan Academic Advisory Board and the B+L Advisory Board.