Living Library

Contact Lens-Induced Acute Red Eye (CLARE)

Previously referred to as: Acute Red Eye (ARE)/Tight Lens Syndrome

Contact Lens-Induced Acute Red Eye (CLARE) reaction typically presents as an acute inflammatory response of the anterior segment characterized by severe conjunctival & especially circumlimbal hyperemia. Both diffuse & focal subepithelial infiltrates are present across the cornea with focal infiltrates often more dense in the periphery after being released from the limbal vasculature. Areas of white and hazy edematous cornea are prominent, but are not associated with significant epithelial defects. Corneal staining, when present, is usually superficial & scattered. Anterior uveitis is present in severe cases. Milder presentations have been reported. While CLARE has been reported with EW RGP lenses, silicone elastomer lenses, and with the over wear of daily soft lenses, a history of extended wear with hydrogel lenses is most typical, as is a uniocular presentation.  
Because of the acute onset of onset of symptoms, patients are often awakened from sleep with severe pain, copious tearing, extreme photophobia, and intense injection. A call to a practitioner soon follows with the description of symptoms sounding strikingly similar to the symptoms of infectious keratitis. The distressed patient presents with head bowed, sunglasses on, and a handfull of tissues close at hand.
Because CLARE reactions are so strongly associated with hydrogel EW wear, a practitioner with few EW patients would rarely see this condition. On the other hand, clinicians monitoring a significant number of patients in EW research studies report yearly incidence rate between 4% to 30 % depending on lens type, lens care regimen, and lens replacement frequency. Studies at the CCLRU do indicate that the CLARE response is most commonly observed during the first 3 months of extended wear, even though it can occur at any time.
The characteristic CLARE signs & symptoms are clearly an inflammatory reaction. Strong evidence from several sources now indicates that inflammatory mediators such as endotoxins released from gram-negative bacteria on the lenses or in the solutions & cases are responsible for this immune reaction. In the past, extended wear hydrogel wearers who experience CLARE reactions, showed repeated high levels of gram-negative bacterial lens contamination compared to asymptomatic EW wearers. This bacterial etiology seems even more likely once researchers accidentally created CLARE reactions in patients. Holden, LaHood, Grant et al reported that inadvertent contamination of hydrogel lenses worn overnight led to CLARE reactions in 33% of the patients and the production of infiltrates in in an additional 44% of the subjects. Very specific strains of gram-negative bacteria species have been isolated & identified from CLARE patients and include, thus far, Pseudomonas spp, Serratia spp & Haemophilus influenzae. Evidence suggests that the specific bacterial strains causing the inflammatory CLARE reaction differ from strains of the same species causing corneal ulceration. Until recently, it has been postulated that CLARE was a response to chronic corneal hypoxia from hydrogel over wear and/or tight fitting lenses. Reports by Stapleton as well as Vajac and Holden indicated that corneal edema present in the CLARE response is more likely a result of the inflammation rather than an etiological factor in CLARE. Non-moving lenses were also often observed in the presenting patient, which suggested an etiology and the name, the Tight Lens Syndrome. However, since the CLARE response has been documented in freely moving lenses, this theory holds less promise. Other suggested causes have been an immune reaction to cellular debris trapped behind a lens, and preservative sensitivity.
There is universal agreement that management begins with the immediate discontinuation of contact lens wear. Cycloplegia is indicated in cases where an anterior uveitis is present. Beyond these measures, treatment for the CLARE response varies from country and region. Clinicians in areas with limitations on the practitioner's therapeutic armamentarium indicate that if diagnosed correctly, CLARE does not requ;ire therapeutic intervention. The traditional approach in these regions allows for natural resolution of the inflammation and corneal infiltrates without lens wear while monitoring the patient's condition. The resolution of the infiltrates occurs over days to weeks. The patient is then typically instructed to recommence lens wear, on a daily wear basis with a fresh lens. After a few weeks of without complications, EW wear can often be successfully re-instituted with a warning to patients that they are more susceptible to repeat episodes of CLARE. The majority of the published CLARE documentation and research comes from these regions. In other regions, such as the United States, patient expectations, societal medico-legal conditions, and therapeutic privileges often lead to more aggressive approaches. Because CLARE's presentation (symptoms and some signs) is similar to infectious keratitis, some practitioners advocate using a broad spectrum topical antibiotic during the first 24-48 hours. This management is appropriate & prudent when there is any epithelial disruption believed to be associated with an infiltrate. After 24-48 hours, some practitioners add a steroid to help reduce the inflammation. Following a careful diagnosis, other practitioners prefer addressing the inflammation as quickly as possible by using a combination antibiotic-steroid medication immediately. The pain in mild cases may be alleviated with topical and/or oral NSAIDs. Inflammation typically resolves after a period of several days to weeks. Once this has occurred, a change in lens parameters, wearing schedule, and/or lens type is indicated. If tight fitting lenses can be identified, then looser ones should be fit. If over wear is implicated, then every attempt should be made to switch to a daily wear schedule. For pajtients not willing to give up extended wear, a new option has recently been introduced: silicone hydrogel lenses. These lenses have oxygen transmissibility values that could only have been dreamt of just a few years ago. Bausch & Lomb's PureVision (Balafilcon A) has a Dk/L of 110, while Ciba Vision's Focus Night & Day (Lotrifilcon A) has a Dk/L of 175. Both exceed existing oxygen criteria for overnight wear. Studies also suggest that they are less conducive to bacterial adhesion compared to standard hydrogel lenses.
Swarbrick HA, Holden BA. Complications of Hydrogel Extended Wear Lenses (Chapter 14, pages 288; 273 - 275). In Silbert JA (editor): Anterior Segment Complications Of Contact Lens Wear 2nd ed.. Butterworth-Heineman, Boston, 2000.
Sankardurg PR; Sharma S; Willcox M; Naduvilath TJ; Sweeney DF; Holden BA; Rao GN. Bacterial colonization of disposable soft lenses is greater during corneal infiltrative events than during asymptomatic extended lens wear. J Clin. Microbiol 2000 Dec;38(12): 4420-4
Silbert JA. Inflammatory Responses in Contact Lens Wear, pages 109; 125- 126). In Silbert JA (editor): Anterior Segment Complications Of Contact Lens Wear 2nd ed.. Butterworth-Heineman, Boston, 2000.
Townsend WD. Managing Those Rare Contact Lens Complications. Contact Lens Spectrum 13/12: 23-24, 1998.d extended disposable contact lens wearers. Clin Exp Optom 1999;82:4-10.
Mack C. Diagnosing and Treating Contact Lens Complications. Contact Lens Spectrum 15/7, 2000.
Sankardurg PR, Sharma S, Gopinathan U, Janakiramen D, Hickson S, Vuppala N, Sweeney DF, Rao GN, & Holden BA. Haemophilus influenzae adherent to contact lenses associated with production of acute ocular inflammation. J Clin. Microbiol 1996 Oct;34(10): 2426-31.
Holden BA, LaHood D, Grant T, Newton-Howes J, Baleriola-Lucus C, Willcox MD, & Sweeney DF. Gram-negative bacteria can induce contact lens related acute red eye (CLARE) responses. CLAO J 1996 Jan;22(1):47-52.
Grant TJ, Terry R, Holden BA. Soft Lens Extended Wear (Chapter 3). In Harris, MG (editor): Contact Lenses: Treatment Options for Ocular Disease. Mosby, St Louis, 1996.
Stapleton F, Lakshmi KR, Kumar S, Sweeney DF, Rao GN, & Holden BA. Overnight corneal swelling in symtomatic & asymptomatic contact Lens wearers. CLAO J, 1998 Jul: Vol. 24(3): 169-74.
Holden BA, Swarbrick HA. Extended Wear: Physiologic Considerations (Chapter 28). In Bennett ES, Weissman BA (editors): Clinical Contact Lens Practice. Lippincott - Raven, Philadelphia,1996.
Vajdic CM, Holden BA: Extended-wear contact lenses. Page 132. In Hamano H, Kaufman HE (eds) Corneal Physiology and Disposable Contact Lenses. Butterworth-Heinemann , Boston, 1997.
Fichman S, Baker VV, Horton HR: Iatrogenic red eyes in soft lens wearers. International Contact Lens Clinic 15:202, 1978.

Cornea and Contact Lens Living Library
Contact Lens-Induced Acute Red Eye (CLARE)

Edited by:
Arnie Patrick, O.D., Nova Southeastern College of Optometry
William Edmondson, O.D., M.S., Northeastern State University College of Optometry