Incidence, risk factors, and patient characteristics in severe contact lens-related microbial keratitis.

Purpose: The aim of the present study was to determine the incidence, patient characteristics, and risk factors for severe, contact lens-related keratitis in patients in need of hospitalization.

Methods: Keratitis was defined as severe when the disease required hospitalization. All patients with contact lens-related keratitis hospitalized at our department between 1 January 2018 and 31 December 2020 were interviewed with a questionnaire, about their use of contact lenses and knowledge of complications. Clinical information was collected from the medical records.

Results: A total of 41 patients (42 eyes) were hospitalized with severe keratitis during the 3-year period. The yearly incidence was 2.52 per 10 000 contact lens users over the age of 15 for extended-wear lenses used overnight, and 0.52 per 10 000 for users of daily disposable contact lenses. Pseudomonas aeruginosa was the most frequently isolated microbe. The median age was 50 years (range 15-66 years). Twenty-three patients (56%) were female, 28 patients (66%) used extended-wear contact lenses and 12 patients (29%) used daily disposable lenses. Nineteen patients (45%) admitted improper use. The median duration of contact lens use was 11.5 years. Only 15 patients (37%) had knowledge of keratitis as a potential complication.

Conclusion: Most patients were experienced contact lens users. Users of extended-wear contact lenses worn overnight had a significantly higher risk of severe microbial keratitis. More focus on information and education of the risk of keratitis in contact lens users is needed.