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Updated: Mar 13, 2026
Development of an In Vitro Ocular Platform to Test Contact Lenses
Published on: April 6, 2016
Melimine-Coated Antimicrobial Contact Lenses Reduce Microbial Keratitis in an Animal Model
Debarun Dutta1, Ajay K Vijay1, Naresh Kumar2
1School of Optometry and Vision Science, University of New South Wales, Sydney, Australia.
Purpose:
To determine the ability of antimicrobial peptide melimine-coated contact lenses to reduce the incidence of microbial keratitis (MK) in a rabbit model of contact lens wear.
Methods:
In vitro antimicrobial activity of melimine-coated contact lenses was determined against Pseudomonas aeruginosa by viable count and a radiolabeled assay. The amount of lipopolysaccharide (LPS) associated with bacteria bound to melimine-coated and control lenses was determined. Ocular swabs from rabbit eyes were collected for assessment of ocular microflora. A rabbit model for MK was developed that used overnight wear of contact lenses colonized by P. aeruginosa in the absence of a corneal scratch. During lens wear, detailed ocular examinations were performed, and the incidence of MK was investigated. Bacteria associated with worn lenses and infected corneas were determined by viable plate count.
Results:
Inhibition in viable and total P. aeruginosa adhesion by melimine-coated contact lenses was 3.1 log10 and 0.4 log10, respectively. After colonization, the amount of LPS on lenses was approximately the same with or without melimine. Gram-positive bacteria were found in all the ocular swabs followed by fungus (42%). Melimine-coated lens wear was protective and significantly (odds ratio 10.12; P = 0.012) reduced the incidence of P. aeruginosa-driven MK in the rabbit model. The antimicrobial lenses were associated with significantly (P < 0.001) lower ocular scores, indicating improved ocular signs compared with controls.
Conclusions:
This study showed that contaminated contact lenses can produce MK without corneal epithelial defect in an animal model. Melimine-coated contact lenses reduced the incidence of MK associated with P. aeruginosa in vivo. Development of MK requires viable bacteria adherent to contact lenses, and bacterial debris adherent at the lens surface did not cause keratitis.
Insights
Antimicrobial peptide melimine-coated contact lenses significantly reduced microbial keratitis (MK) in a rabbit model. These novel lenses offer protection against Pseudomonas aeruginosa infections during contact lens wear.
Area of Science:
- Ophthalmology
- Biomaterials Science
- Infectious Diseases
Background:
- Microbial keratitis (MK) is a serious complication of contact lens wear.
- Pseudomonas aeruginosa is a common pathogen causing contact lens-related MK.
- Current contact lens materials may not adequately prevent bacterial adhesion and infection.
Purpose of the Study:
- To evaluate the efficacy of melimine-coated contact lenses in preventing MK.
- To assess the antimicrobial activity of melimine against P. aeruginosa in vitro and in vivo.
- To determine if melimine-coated lenses reduce MK incidence in a rabbit model.
Main Methods:
- In vitro testing of melimine-coated lenses against P. aeruginosa.
- Quantification of bacterial adhesion and lipopolysaccharide (LPS) on lenses.
- Development of a rabbit model for MK using P. aeruginosa-colonized lenses.
- Ocular examination and MK incidence assessment in rabbits.
Main Results:
- Melimine coating significantly inhibited P. aeruginosa adhesion to contact lenses.
- Melimine-coated lenses reduced the incidence of P. aeruginosa-induced MK in rabbits by 10.12-fold.
- Antimicrobial lenses were associated with significantly improved ocular scores.
Conclusions:
- Contaminated contact lenses can cause MK even without corneal defects.
- Melimine-coated contact lenses demonstrate significant in vivo efficacy against P. aeruginosa-related MK.
- Viable bacteria adhering to lenses are crucial for keratitis development.
