Microbial Keratitis, A Primary CL Associated Complication

Man with sore eye
Proper cleaning, disinfection, and handling techniques can minimize exposure to sight-threatening microbes, according to a study.

Microbial keratitis appears to be a primary contact lens associated complication, while Pseudomonas aeruginosa and Acanthamoeba were the most commonly identified pathogens found in patients’ eyes, according to a study published in Eye & Contact Lens.

Investigators conducted this retrospective analysis by surveying 964 ophthalmologist training facilities that treated cases of contact lens–associated complications between April 2016 and March 2018. Inclusion criteria involved a corrected distance visual acuity of ≤0.1 decimal after treatment for 3 months, corneal perforation during follow-up, and required surgery. Investigators obtained information on the type of contact lenses worn, clinical manifestations, and course of treatment for all participants.

Overall, 42 patients presented with infectious keratitis. Participants included 21 men and 21 women with an average age of 44.16 years (range, 15–75 years). All cases of keratitis were unilateral, with the left and right eye affected in 55% and 45% of patients, respectively. Most patients used soft contact lenses (81%), while the remaining patients  used rigid gas-permeable contact lenses (19%). 

Microbiological tests were positive in 73% of cases after analyzing samples from the cornea (92%), conjunctiva (5.4%), or eye discharge (2.7%). Organisms isolated from the microbiological cultures included bacteria (Pseudomonas aeruginosa n=9; Staphylococcus epidermis n=1; Streptococcus pneumoniae n=1), fungi (n=2), and Acanthamoeba (n=14). Multiple organisms were isolated in 7 cases of bacterial keratitis. Bacteria were also identified in 6 cases of Acanthamoeba keratitis with 1  (gram-positive cocci [strain undefined], gram-positive rod [strain undefined], Propionibacterium acnes, Enterobacter agglomerans, or Escherichia coli) or 2 organisms (Sphingobacterium and Stenotrophomonas maltophilia). Fungi and P. aeruginosa were both detected in 1 case of keratitis.

Treatments included local antibiotics (n=10), a combination of systemic antibiotics (n=11), and a combination of surgical approaches (n=21), including 13 corneal transplants. 

“The major cause of serious contact lens–associated ocular complications was microbial keratitis, and P. aeruginosa and Acanthamoeba were the major pathogens” according to investigators. “Caution is required regarding the adequate usage of contact [lenses] to prevent sight-threatening results because of microbial keratitis.

Limitations of the study included its retrospective design, variability in records and data availability across multiple centers, and a lack of information about the contact lenses used.


Shigeyasu C, Yamada M, Fukuda M, et al. Severe ocular complications associated with wearing of contact lens in Japan. Eye Contact Lens. Published online December 1, 2021. doi:10.1097/ICL.0000000000000870