Discussion

This case series of contact lens–related corneal infections highlights the burden these infections place on contact lens wearers and the serious outcomes associated with them. All of the patients required treatment with antibiotic eye drops, sometimes requiring administration hourly for weeks or months. This finding is consistent with a previous analysis of administrative health care data, which indicated that 76% of keratitis patient encounters were associated with an antimicrobial prescription (1). Some of the patients described in this series sought care in an emergency department, where it is more costly to receive care (1). One patient was lost to follow-up care, suggesting possible complete resolution of disease, but also highlighting the challenge of complying with medical care by patients who might be busy with work, school, or household obligations. Two patients required surgery, and most were left with permanent eye damage or vision loss. Contact lens wearers are younger on average than nonwearers and bear a burden of disease despite being viewed as healthy.

Exam findings in these patients were indicative of active infection including stromal opacification, anterior chamber reaction, and hypopyon. Cultures and diagnostic testing identified various organisms, including Pseudomonas aeruginosa and Acanthamoeba spp., which might suggest contamination of contact lenses and supplies with tap water.

In three of the six cases, contact lenses were purchased without a valid prescription. In one case, they were decorative lenses, which are lenses that alter the appearance of the eye (e.g., change the color) but might not improve vision. Decorative lenses, similar to lenses that are prescribed for vision correction, are classified as medical devices. The sale of all contact lenses is regulated and should require a valid prescription from an eye care professional. In the United States, contact lens prescriptions are valid for only 1–2 years, depending on the state. Visits with an eye care professional to renew a prescription serve as opportunities for reeducation about safe contact lens wear and care practices.

Sleeping in contact lenses is one of the most frequently reported contact lens risk behaviors and one with a high relative risk for corneal infection (3,4). Sleeping in lenses has been shown to be a risk factor regardless of lens material and frequency, with even occasional overnight use conferring risk (5,6). Although some contact lenses are approved by FDA for overnight wear, the increased risk for infection is acknowledged by their classification as a Class 3 medical device, which includes medical devices with the greatest risk for harm such as intraocular lenses and implantable pacemakers. Postmarketing surveillance of drugs and devices is important to the health and safety of the general public. Whereas medical device manufacturers are required to report adverse events, not all adverse events come to the attention of manufacturers (7). Patients and physicians can fill this gap.

The findings in this report are subject to at least three limitations. First, cases were chosen by practicing ophthalmologists (who can perform eye surgery), and are likely referred cases of contact lens–related eye infections that are more serious and might require surgical intervention. Therefore, the cases presented here are not necessarily representative of the typical contact lens–related eye infection. Second, as a case series, there are no definitive statements that can be made regarding the association of the reported risk factors and the contact lens–related eye infections. Finally, the patients in the cases reported here might have had an innate susceptibility to developing an eye infection; other contact lens wearers with the same habits might be able to sleep in lenses without adverse outcomes.

Cases of contact lens–related infections, such as those described here, should be reported as adverse events to the FDA Safety Information and Adverse Event Reporting Program at http://www.fda.gov/MedWatchexternal icon. The Eye and Contact Lens Association is working to promote contact lens safety for patients by encouraging eye care professionals and patients to voluntarily report contact lens–related eye infections to FDA. Using the data accumulated in the adverse event reporting program, contact lens stakeholders (industry, regulatory authorities, eye care professionals, and public health) can work together to determine what improvements can be made to contact lenses, care products, manufacturer guidelines, and labeling. Health education measures directed toward contact lens wearers should emphasize raising awareness of the risks of sleeping in contact lenses as well as adherence to all recommendations for the wear and care of contact lenses.