Keratitis, CL-associated infiltrative

The CMGs are guidelines on the diagnosis and management of a range of common and rare, but important, eye conditions that present with varying frequency in primary and first contact care.

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Contact lens-associated infiltrative events (CIEs), including:

  • contact lens-associated peripheral ulcer (CLPU)
  • contact lens-associated infiltrative keratitis

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

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 around 3%. The incidence in extended soft lens wearers ranges from 2.5 to 6%; if asymptomatic CIEs are included, the incidence can be as high as 20–25%

Predisposing factors

Demographic and person related:

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

Contact lens–related:

  • extended wear
  • silicon hydrogel material
  • multipurpose contact lens solutions
  • bioburden of lenses and lens case


Eye moderately red and slightly watery
Mild foreign body sensation
Mild photophobia
(NB: symptoms vary in severity; some cases are asymptomatic)


Peripheral anterior stromal infiltrate, single or multiple
Usually small (generally less than 1.0mm in diameter)
Overlying epithelium usually stains with fluorescein
Conjunctival hyperaemia, mild
Epiphora, mild (or absent)
Anterior chamber quiet or mildly inflamed
No lid oedema
Usually unilateral

Differential diagnosis

Microbial (bacterial or fungal) keratitis

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

Marginal keratitis
Corneal scar
Herpes simplex keratitis
Adenovirus keratoconjunctivitis

Management by optometrist

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

Non pharmacological

Temporarily discontinue lens wear

  • most signs and symptoms resolve within 48 hours
  • infiltrates resolve over 2-3 weeks

Advise against extended wear
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 for blepharitis (see Clinical Management Guideline on Blepharitis)

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

Management category

B2: alleviation / palliation: normally no referral

Possible management by ophthalmologist

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

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

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

Plain language summary

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.

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 6
Date of search 24.05.19
Date of revision 29.05.19
Date of publication 22.03.21
Date for review 23.05.21
© College of Optometrists 

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