Conjunctival cytology in hard and soft contact lens wear.

The conjunctival cytological profiles of asymptomatic healthy contact lens wearers are described. An impression biopsy technique (5 h after insertion of contact lenses) was used. Significantly higher cell counts (neutrophils and lymphocytes) were found amongst the soft lens wearers', biopsies compared to hard lens wearers' biopsies or control subjects' biopsies. It is postulated that conjunctival cytological examination may reveal early, subclinical, cytotoxic effects attributable to the preservatives and chelating agents in soft contact lens care systems.