Contact lens-induced Infection - A new model of Candida albicans keratitis

PURPOSE. A model of experimental keratomycosis was established that mimics human disease in which the only fungi present are those that are actively g rowing within the cornea. METHODS. Dutch-belted rabbits received a subconjunctival injection of triam cinolone acetonide to one eye. One day later the epithelium was removed fro m the central cornea and a standardized inoculum of Candida albicans blasto -conidia was placed on the corneal surface and covered with a contact lens. The lids were closed with a lateral tarsorraphy. After 24 hours, the lid s utures and contact lens were removed. Five days later the animals were kill ed, and their corneas were subjected to separate isolate recovery and histo logy studies. A group of similarly infected rabbits without corticosteroid injection served as controls. RESULTS. Both groups developed invasive corneal disease. Although isolate r ecovery was not significantly different from corticosteroid-treated rabbits compared with controls, fungal biomass was increased. Hyphal invasion was limited to the anterior cornea in control eyes, but penetrated deep stroma in most of the corticosteroid-treated rabbits. CONCLUSIONS. Invasive corneal disease can be established with a surface ino culum. Corticosteroid administration increased corneal penetration of hypha e. Quantitative isolate recovery is not a reliable measure of the fungal lo ad within the cornea.