The upswing of two rare eye infections among soft contact lens wearers within the past 2 years is leading some professionals in the contact lens community to reconsider trends that emphasized comfort, perhaps at the expense of efficacy. Ophthalmologists, manufacturers, and industry analysts are predicting a return to "rub-required" cleaning regimens or hydrogen peroxide cleaning solutions that require more steps but might be more effective.
"There's no doubt in my mind that lenses are cleaned better if they're rubbed, and if those patients with Fusarium [keratitis] a year ago or Acanthamoeba [keratitis] more recently had digitally rubbed their lenses-old style, if you will-chances are, they would not have had this issue," said Jeffrey D. Johnson, OD, senior research analyst with Robert W. Baird & Co.
As Advanced Medical Optics (AMO) considers options following the May 25 voluntary global recall of its multipurpose contact lens solution (Complete MoisturePlus) and an outbreak of Acanthamoeba keratitis cases among contact lens wearers, company officials said they would move away from "no rub" claims (Ophthalmology Times, June 15, 2007, see "AMO recalls lens solution"). No evidence suggests that the voluntary recall is related to a product contamination issue, according to AMO. Company officials are working with the Centers for Disease Control and Prevention (CDC), FDA, and others; investigators continue to seek the source of Acanthamoeba keratitis among contact lens wearers.
The recall of AMO's contact lens solution came 1 year and 10 days after Bausch & Lomb recalled its multipurpose contact lens solution (ReNu with MoistureLoc) as last spring's outbreak of Fusarium keratitis was associated with use of the contact lens cleaning solution and common suboptimal hygiene practices (JAMA 2006;296:953-963).
In the more recent AMO case, 138 patients in 35 states and Puerto Rico tested positive for Acanthamoeba keratitis since Jan. 1, 2005, according to the CDC. A preliminary analysis by the CDC revealed that patients with the infection who used soft contact lenses were at least seven times more likely to have used AMO's solution compared with a group of healthy adult soft contact lens wearer.
A care continuum
Contact lens wearers in the 1970s and 1980s relied on heat to clean their lenses before turning to multi-bottle hydrogen peroxide systems that were simplified to a single-bottle hydrogen peroxide regimen. Those who failed to neutralize their peroxide with a platinum disk or tablet, however, experienced a painful corneal burn, Dr. Johnson explained.
Still searching for easier and more comfortable cleaning methods, manufacturers began producing single-bottle multipurpose solutions that required patients to rub their lenses for 10 seconds before dropping them into their cases. That gave way to "no rub required" solutions in the past 5 to 10 years, said William H. Ehlers, MD, president of the Contact Lens Association of Ophthalmologists.
"Over the [past] 30 years, there's been a continuum of trying to get more and more convenient and more and more comfortable," Dr. Johnson said. "I question whether we tipped the scales of going too far in that continuum."