Etiological and Clinical Features of Contact Lens-Associated Microbial Keratitis

To determine the demographic, etiological, microbiological, and clinical characteristics and present treatment results of contact lens (CL)-associated microbial keratitis (CLAMK).

Medical records of patients who were followed in our clinic for CLAMK between January 2014 and May 2020 were retrospectively analyzed. Demographic characteristics, symptom duration, CL and usage characteristics, risk factors, isolated microorganisms, lesion characteristics, hospital stay, recovery and follow-up times, and best corrected visual acuities (BCVA) at first and last examination were recorded.

The 22 patients (16 females, 6 males; 22 eyes) had a mean follow-up time of 13.0±18.3 months and mean age of 26.9±14.3 years. Most of the female patients (13/16) were under 35 years old. At least one risk factor associated with improper CL usage was identified in 21 patients (95.4%). The most common risk factor was sleeping with CL (n=15, 68.1%). Causative microorganisms were detected on microbiological examination in 15 cases (68.1%). The most common microorganism was Pseudomonas aeruginosa (n=8). Causative pathogens were sensitive at rates of 84.2%, 95% and 94.7% to combined vancomycin/amikacin, combined vancomycin/ceftazidime, and moxifloxacin, respectively. Mean BCVA was 0.9±1.1 logMAR in the first examination and increased to 0.59±1.1 at last examination (p=0.006). There was a negative correlation between BCVA at presentation and length of hospital stay (p=0.014).

Mistakes in CL use are a frequent predisposing factor in patients with CLAMK. Informing CL users in detail about CL usage and cleaning may reduce the frequency of these mistakes and thus infections. Current antibiotic options that should be preferred in empirical treatment remain largely effective against likely pathogens. Favorable visual outcomes can be obtained in most cases with detailed diagnostic examination and appropriate treatment approaches.