This past American Academy of Optometry meeting in Orlando held the inaugural “Think Tank” event. This year’s topic, “Corneal Infections in Contact Lens Wear,” was by all measures a tremendous success. The presenters posed provocative questions that need to be answered if we want to really understand sight-threatening infections in contact lens wearers.
As I listened to the presentations and discussions among the fabulous group of research scientists, clinicians and academics, I jotted down unanswered questions—37 to be exact. I’d like to share just two of those vexing concerns here:
(1) Why hasn’t the overall rate of infections in lens wearers changed in the past two decades despite astonishing advances in both material and design technology and care products, along with campaigns to improve compliance and hygiene?
(2) Are daily disposable lenses really safer to wear than other lens types?
Surprising, the overall rate of corneal infection in lens wear has not improved over the past several decades.1,2 This is somewhat tragic, and even a bit embarrassing, since there has been a good amount of research on material property development, lens design and solution efficacy as well as how to minimize the chances of acquiring an infection.
What should the next steps be to favorably reduce the rate of corneal infection in lens wearers? It is vital that we engage all stakeholders: manufacturers, practitioners and patients. It may appear that we’ve reached the limit of what we can do from a material, design and modality standpoint. But, have we reached the pinnacle of safety in lens technology? What has happened in antimicrobial surface technology to reduce microbial burden? Can genetic testing help us garner valuable information to predict who is most vulnerable to infection?
Continued initiatives to educate patients help assure good practices in compliance and hygiene. The Centers for Disease Control and Prevention’s recent initiatives have been laudable, but the impact of the campaign is hard to determine.
Researchers have generated meaningful data on the risks and overall safety of daily disposable lenses and their rate of infection.1,2 Their findings would suggest that the infection rate of daily disposables is no safer (one to two per 10,000) than other daily wear lenses replaced at less frequent intervals (i.e., two-week or monthly replacements) even when appropriate practices are followed.1
However, serious infections were found to be less common in daily disposable wearers since there were fewer environmental organisms found with cultures of known infections related to daily disposable lens wear (0.5 per 10,000 wearers per year).1 Considering the organisms found in corneal infections in daily disposable lens wearers, the infections may be related to lens handling.1,3
Additional research initiatives are needed to answer many of the questions posed regarding contact lens safety including safety with daily disposable lens wear. New lens designs and material updates have occurred since the completion of previous studies on lens safety. Some daily disposable brands have even been significantly modified. New data is sorely needed to verify any concerns. Will the results mirror those generated in the past?
In no fashion does this brief summary on disposable lens wear safety suggest that daily disposable lenses are not the preferred modality for nearly all lens wearers. Their low rate of corneal infection and favorable, convenient use compared with other options make them ideal.
Future Think Tanks, either as a branded Academy series or discussions conducted by other groups, will prove to be rewarding. Experts in their particular field can examine a topic and formulate pertinent questions that will fundamentally eliminate, or at least minimize or change, that problem. The Think Tank can then serve as a driver for future, valuable research and help move our understanding of a particular problem. Just 35 more to go!
We look forward to the Academy’s summary of the Think Tank proceedings that should be out soon.
1. Stapleton F, Naduilath T, Keay LJ, et al. Risk factors and causative organisms for microbial keratitis in daily disposable contact lens wear. PLoS One. 2017;12(8):e0181343.
2. Stapleton F, Carnt N. Contact lens-related microbial keratitis: how have epidemiology and genetics helped us with pathogenesis and prophylaxis. Eye. 2012;26(2):185-93.
3. Cope JR, Collier SA, Rao MM, et al. Contact lens wearer demographics and risk behaviors for contact lens-related eye infections—United States, 2014. MMWR Morb Mortal Wkly Rep. 2015;64(32):865-70.