Keratitis, CL-associated infiltrative


Contact lens-associated infiltrative events (CIEs) represent a self-limiting inflammatory response of the cornea, affecting the anterior stroma with or without epithelial involvement.

Contact lens-associated infiltrative events include:

  • contact lens-associated peripheral ulcer (CLPU)
  • contact lens-associated infiltrative keratitis
  • contact lens-associated acute red eye (CLARE)

The aetiology of this condition is inflammatory, not infective. Though it is bacteria-related, bacteria do not invade or replicate in the cornea and there is no progression to infection, nor is the condition a marker for increased risk of microbial keratitis, which is a separate disease entity. However, due to similarities with the presentation of microbial keratitis this should be excluded and patients carefully monitored

CL-associated infiltrative keratitis is considered to be a response to microbial (usually Staphylococcal) antigens, derived from bacteria on the lens or on the lid margin. Micro-organisms cannot usually be recovered from the lesions

In daily soft lens wear, the annual incidence of symptomatic CIEs is between 0.5 and 3.3% for daily wear and between 2.5 and 6% for extended (overnight) wear. The incidence of asymptomatic CIEs is considerably higher, 10-25%.

Predisposing factors

Demographic and person related:

  • bioburden of eyelid margins (blepharitis)
  • male sex
  • younger age (<25 years)
  • smoking
  • previous history of CIE

Contact lens–related:

  • long-term lens wear
  • extended (overnight) wear
  • silicon hydrogel material
  • tight lens fit
  • multipurpose contact lens solutions
  • poor lens hygiene
  • bioburden of lenses and lens case

Symptoms of contact lens-associated infiltrative keratitis

Red and watery eye
Foreign body sensation
(NB: symptoms vary in severity; some cases are asymptomatic)

Signs of contact lens-associated infiltrative keratitis

Peripheral anterior stromal infiltrate, single or multiple (multiple infiltrates more likely in CLARE)
Usually small (generally less than 1.0mm in diameter)
Overlying epithelium may stain with fluorescein (ulcer formation in CLPU)
Conjunctival hyperaemia
Adjacent limbal hyperaemia
Epiphora, mild (or absent)
Anterior chamber quiet or mildly inflamed
No lid oedema
Usually unilateral

Differential diagnosis

Microbial (bacterial or fungal) keratitis (see Clinical Management Guideline on Keratitis (bacterial and fungal))

  • appearance can be similar, therefore monitor closely especially over the first 24-48 hours and if diagnosis remains in doubt, refer to hospital eye service as an emergency

Marginal keratitis
Corneal scar
Herpes simplex keratitis
Adenovirus keratoconjunctivitis
Toxic keratopathy e.g. preservative or medication toxicity

Management by optometrist

Practitioners should recognise their limitations and where necessary seek further advice or refer the patient elsewhere

Non pharmacological

Address modifiable risk factors:

  • Temporarily discontinue lens wear
    • most signs and symptoms resolve within 48 hours
    • infiltrates resolve over 2-3 weeks
  • advise against extended wear
  • evaluate lens fit and care regime
  • reinforce education concerning lens hygiene and wearing schedules
  • warn about possibility of recurrence. If condition recurs, switch to disposable CLs
  • lid hygiene if blepharitis present

(GRADE*: Level of evidence=low, Strength of recommendation=strong)


Ocular lubricants for symptomatic relief
Topical antibiotic (chloramphenicol, azithromycin [off-licence use]) / oral antibiotic (tetracycline group) may be indicated if blepharitis present (see Clinical Management Guideline on Blepharitis (lid margin disease))

(GRADE*: Level of evidence=low, Strength of recommendation=weak)

Management category

B2: alleviation / palliation: normally no referral

Possible management in secondary care or local primary/community pathways where available

Additional guidance may be available

Not normally referred

Evidence base

*GRADE: Grading of Recommendations Assessment, Development and Evaluation (

Sources of evidence

Chalmers RL, Hickson-Curran SB, Keay L, Gleason WJ, Albright R. Rates of adverse events with hydrogel and silicone hydrogel daily disposable lenses in a large postmarket surveillance registry: the TEMPO Registry. Invest Ophthalmol Vis Sci. 2015;56(1):654-63

Chalmers RL, Wagner H, Mitchell GL, Lam DY, Kinoshita BT, Jansen ME, Richdale K, Sorbara L, McMahon TT. Age and other risk factors for corneal infiltrative and inflammatory events in young soft contact lens wearers from the Contact Lens Assessment in Youth (CLAY) study. Invest Ophthalmol Vis Sci. 2011;52(9):6690-6

Ho L, Jalbert I, Watt K, Hui A. Current understanding and therapeutic management of contact lens associated sterile corneal infiltrates and microbial keratitis. Clin Exp Optom. 2021;104(3):323-333.

Richdale K, Lam DY, Wagner H, Zimmerman AB, Kinoshita BT, Chalmers R, Sorbara L, Szczotka-Flynn L, Govindarajulu U, Mitchell GL. Case-Control Pilot Study of Soft Contact Lens Wearers With Corneal Infiltrative Events and Healthy Controls. Invest Ophthalmol Vis Sci. 2016;57(1):47-55

Steele KR, Szczotka-Flynn L. Epidemiology of contact lens-induced infiltrates: an updated review. Clin Exp Optom. 2017;100(5):473-481

Suchecki JK, Ehlers WH, Donshik PC. Peripheral corneal infiltrates associated with contact lens wear. CLAO J. 1996;22(1):41-6.

Sweeney DF, Jalbert I, Covey M, Sankaridurg PR, Vajdic C, Holden BA, Sharma S, Ramachandran L, Willcox MD, Rao GN. Clinical characterization of corneal infiltrative events observed with soft contact lens wear. Cornea. 2003;22:435-42

Szczotka-Flynn L, Jiang Y, Raghupathy S, Bielefeld RA, Garvey MT, Jacobs MR, Kern J, Debanne SM. Corneal inflammatory events with daily silicone hydrogel lens wear. Optom Vis Sci. 2014;91:3-12


What is Contact Lens (CL) associated Infiltrative Keratitis?

This condition, affecting contact lens wearers, has been given many different names. It is an inflammation of the cornea (the clear window of the eye) caused by a reaction to bacteria on the surface of the contact lens. Patients experience slight discomfort, redness and watering of the eye (it usually affects just one eye) and they may be unduly sensitive to light. The optometrist will see a small opaque area or areas near the edge of the cornea, plus inflammation of the white of the eye.

How is CL-associated Infiltrative Keratitis managed?

The most important task of the optometrist is to distinguish between this condition and an actual infection of the cornea, which is a sight-threatening emergency. Stopping contact lens wear usually allows the symptoms and most of the signs to resolve within 48 hours.

Patients will usually need to be reminded of contact lens hygiene measures, including hand washing before handling their lenses, the need to replace their lens case frequently and avoiding overnight wear of their lenses.

Keratitis, CL-associated infiltrative
Version 8
Date of search 02.10.23
Date of revision 27.11.23
Date of publication 23.01.24
Date for review 01.10.25
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