Ying Hong,¹ Chun Zhang,¹ Liping Duan,² Wei Wang¹
Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand

Aim: To evaluate the clinical characteristics, risk factors, management, and outcome of infectious keratitis associated with contact lens wear.
Methods: The study comprised all consecutive patients presenting with contact lens–related presumed microbial keratitis during a 5-year period. Detailed demographic data, type of contact lens, risk factors, clinical findings, microscopic profile, treatment, and final visual outcome were evaluated.
Results: Thirty six patients had contact lens-associated bacterial keratitis; 30 patients used daily-wear soft lenses, 4 used extended-wear soft lenses, and 2 used hard lenses. Pseudomonas aeruginosa was isolated in 38.8% of patients and Staphylococcus aureus in 13.8%; β-haemolytic Streptococcus, Serratia marcescens, and Staphylococcus epidermidis were also common pathogens. The risk for keratitis due to overnight contact lens wear was 33.3%. Twenty six patients (72.2%) presented with initial visual acuity of 6/36 or worse. Visual acuity following treatment improved for 13 patients (36.1%).
Conclusion: Contact lens-associated keratitis was seen most frequently in patients using daily-wear soft contact lenses. Pseudomonas aeruginosa was the most commonly encountered causative agent. Overnight contact lens wear is a major risk factor for keratitis among contact lens wearers. Therefore, overnight wear should be avoided.

Key words: Contact lenses, Keratitis, Pseudomonas aeruginosa

Asian J Ophthalmol. 2007;9:209-212.