title: Microbial contamination of in-use ocular medications.
abstract: Two hundred twenty in-use medications from 101 patients with nonmicrobial ocular surface disease were studied by culturing the bottle caps, a drop produced by simple inversion, and the interior contents removed sterilely. Conjunctival cultures were taken from these patients and 50 age-matched controls. Pathogenic organisms were harvested from conjunctivae significantly more frequently (P less than .01) from cases (34 of 101) than from controls (five of 50). Sixty-four medications (29%) had microorganisms cultured from at least one medication site. Gram-negative organisms were significantly more likely (P less than .00001) to be isolated from all medication sites than gram-positive organisms. Additionally, when isolated from medication sites, the gram-negative organisms were highly likely to be cultured from the conjunctiva as well. This was not true for pathogenic gram-positive organisms. We conclude that a cycle of contamination between in-use medications and conjunctivae may represent an important risk factor for microbial keratitis in patients with ocular surface disease.
authors.affiliation: Dana Center for Preventive Ophthalmology, Wilmer Institute, Johns Hopkins University, Baltimore, Md 21205.
authors.forename: O D
authors.initials: OD
authors.lastname: Schein
authors.forename: P L
authors.initials: PL
authors.lastname: Hibberd
authors.forename: T
authors.initials: T
authors.lastname: Starck
authors.forename: A S
authors.initials: AS
authors.lastname: Baker
authors.forename: K R
authors.initials: KR
authors.lastname: Kenyon
mesh_terms: D003228:Conjunctiva / Q000382:microbiology; D004340:Drug Contamination; D005128:Eye Diseases / Q000382:microbiology*; D015817:Eye Infections / Q000382:microbiology; D005260:Female; D005658:Fungi / Q000302:isolation & purification; D006090:Gram-Negative Bacteria / Q000302:isolation & purification*; D006094:Gram-Positive Bacteria / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008828:Microbiological Techniques; D008875:Middle Aged; D009824:Ointments; D009883:Ophthalmic Solutions
chemical_list: D009824:Ointments; D009883:Ophthalmic Solutions