Conjunctivitis or pinkeye

  Conjunctivitis (commonly called "pinkeye") is an inflammation of the conjunctiva (the outermost layer of the eye and the inner surface of the eyelids), often due to infection. It may also be caused by adenoviruses.

  Blepharoconjunctivitis is the combination of conjunctivitis with blepharitis.
Keratoconjunctivitis is the combination of conjunctivitis and keratitis.

Investigations

  These are done infrequently because most cases of conjunctivitis are treated empirically and (eventually) successfully, but often only after running the gamut of the common possibilities.

  Swabs for bacterial culture are necessary if the history & signs suggest bacterial conjunctivitis, but there is no response to topical antibiotics. Research studies indicate that many bacteria implicated in low-grade conjunctivitis are not detected by the usual culture methods of medical microbiology labs, so negative results are common. Viral culture may be appropriate in epidemic case clusters. Conjunctival scrapes for cytology can be useful in detecting chlamydial and fungal infections, allergy and dysplasia, but are rarely done because of the cost and the general lack of laboratory staff experienced in handling ocular specimens. Conjunctival incisional biopsy is occasionally done when granulomatous diseases (e.g., sarcoidosis) or dysplasia are suspected.