Contact Lens-associated Microbial Keratitis

Contact lenses are widely used not only for vision correction but also for various other purposes, and their global usage continues to increase steadily. However, contact lens wear carries the risk of several complications, among which microbial keratitis is a serious condition that can lead to significant visual impairment. Contact lens wearers are reported to have up to an 80-fold higher risk of developing microbial keratitis compared to non-wearers, with <i>Pseudomonas aeruginosa</i> being the most commonly identified pathogen. Infections caused by non-bacterial organisms such as fungi and Acanthamoeba are also not uncommon. The risk of infection is closely related to factors such as lens material, wearing habits, and hygiene practices. Early diagnosis and pathogen-specific treatment are critical in determining the prognosis. In recent years, increasing antibiotic resistance, the emergence of novel infectious diseases, and changes in climate and environmental conditions have complicated the etiology and treatment of microbial keratitis, demanding more effective responses. Education on proper lens care and hygiene remains the most essential preventive measure, and prompt diagnosis followed by appropriate treatment is vital when infection occurs. In addition to conventional antibiotic therapy, new treatment modalities such as corneal cross-linking and rose bengal photodynamic antimicrobial therapy are being explored clinically, warranting further research and the establishment of standardized guidelines. This review aims to provide a comprehensive overview of the epidemiology, pathophysiology, causative organisms, diagnostic approaches, treatment strategies, and emerging therapies for contact lens-related microbial keratitis.