A case of recalcitrant bacterial conjunctivitis.

It is important to be vigilant for retained foreign bodies as a cause of recalcitrant bacterial conjunctivitis, even in the absence of foreign body sensation. A relapsing-remitting history should prompt referral to an ophthalmology department. All patients presenting with a red eye should be asked specifically about contact lens wear, and causes of conjunctivitis other than those bacterial in nature--such as viral and chlamydial infections or allergy--should be borne in mind. Contact lens wear may cause ocular complications, ranging from mild dry eye symptoms to contact lens-associated microbial keratitis, which is an ophthalmic emergency. Contact lens-associated corneal infections caused by Pseudomonas aeruginosa, which can rapidly penetrate the cornea, or Acanthamoeba can be severe and sight threatening. All patients with a history of contact lens wear and red flag symptoms such as eye pain, redness, reduction or change in vision, corneal epithelial defect, discharge, foreign body sensation or failure to respond to antibiotics should be referred for an urgent ophthalmic review. Retained contact lenses are known to cause several ocular complications, such as giant papillary conjunctivitis and ulcerative keratitis which may threaten corneal penetration. Lid eversion may reveal a hidden sub-tarsal contact lens. Use of fluorescein may also allow visualisation of any corneal epithelial defect. A careful slit lamp examination by an ophthalmologist is required to exclude this critical finding definitively.