Related Experiment Video
Updated: Aug 15, 2026

Conjunctival Commensal Isolation and Identification in Mice
Published on: May 1, 2021
Gram-negative bacteria can induce contact lens related acute red eye (CLARE) responses
B A Holden1, D La Hood, T Grant
1Cornea and Contact Lens Research Unit, University of New South Wales, Sydney, Australia.
Purpose:
Twelve volunteers participated in a study designed to measure the overnight corneal edema response with a variety of hydrogel contact lenses. During the study four subjects (5 eyes) experienced a contact lens related acute red eye (CLARE) reaction, which manifested as severe ocular pain, photophobia, corneal infiltration, and conjunctival hyperemia. An additional five subjects (7 eyes) developed corneal infiltrates only. Twelve eyes (of 9 subjects) showed no response.
Methods And Results:
Upon microbiological examination of the contact lenses and storage solutions, gram-negative bacteria were isolated in large amounts. The bacteria were identified as Serratia marcescens, Pseudomonas putida, and Pseudomonas aeruginosa. Significantly greater numbers of bacteria were isolated from contact lenses of subjects who experienced CLARE than from the other subjects (P = 0.005) and from the contact lenses of subjects who experienced an adverse reaction (CLARE or infiltrates) than from the other subjects (P < 0.001). The contaminating bacteria are thought to have been introduced to the lens storage vials as a result of lens handling and subsequent failure to disinfect lenses.
Conclusions:
This study draws attention to the possible contribution of contaminated lenses and storage cases in contact lens related acute inflammation and specifically implicates gram-negative bacteria, in particular Pseudomonas spp. and Serratia spp., in the inducement of acute inflammatory reactions such as CLARE.
Related Concept Videos
Allergic Drug Reactions
Angle Closure Glaucoma: Treatment
Defense Against Bacterial Pathogens
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
Hypersensitivity Reactions: Cytolytic Reactions
Microbiome of the Eye
Bacterial Meningitis

