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Signs and Symptoms
Contact lens acute red eye (CLARE), as the name implies, is an acute inflammatory condition associated with contact lens wear. The classic presentation involves a patient in extended-wear hydrogel contact lenses who, upon awakening, experiences ocular pain (e.g., foreign body sensation), tearing, variably decreased vision and photophobia. Clinically, CLARE manifests as an acute keratitis marked by mid-peripheral corneal infiltrates in the most severe cases.1 These infiltrates may emanate from and accumulate near encroaching limbal vessels. Associated clinical signs include moderate-to-severe conjunctival and limbal hyperemia, corneal edema and mild-to-moderate blepharospasm. Pronounced lid edema, corneal epitheliopathy and anterior chamber reaction are notably absent.
Often, patients with CLARE will have a history of poor contact lens hygiene, excessive wearing time or frank contact lens abuse. In some cases, the contact lens shows inadequate movement, and the patient may be physically unable to remove the lens from the eye during the initial episode. Immobility of the lens is, however, not uniformly encountered. CLARE may occur both with well-fitted and poorly-fitted lenses and may be seen with low or high dK/L materials, including silicone hydrogels and gas permeable lenses.2,3
Pathophysiology
CLARE represents a sterile inflammatory keratitis that is associated with bacterial colonization of the contact lens.4-8 While all contact lenses harbor bacteria, obviously not all patients experience CLARE. This suggests that a combination of factors is involved, including lens-induced hypoxia, mechanical microtrauma from the lens itself and even the type and virulence of the specific bacteria. Gram-negative organisms, particularly Pseudomonas but also Haemophilia and Serratia species, have been most...