Extended wear contact lenses pose safety risks
Published: Monday, June 25, 2012
Updated: Monday, June 25, 2012 01:06
Although contact lenses may be a more attractive and convenient alternative to glasses, some USF professors warn that they come with serious risks.
Though all three types of lenses — disposable, daily and extended wear lenses — are FDA approved, USF clinical professor and optometrist Bruce Anderson said using extended wear lenses could lead to potential medical issues.
These issues, he said, could be avoided if users are aware of the potential complications.
Disposable lenses are the safest to use because they are tossed after one use, and this eliminates the risk of developing a corneal infection from sleeping with the lenses in.
“I discourage extended wear lenses,” he said. “Disposable one-day lenses have the lowest risk on the market.”
Disposable and daily wear contacts are removed at night, but extended wear contacts can be left in for up to 30 days at a time. If left in for too long, contact lenses restrict the amount of oxygen reaching the eyes, possibly leading to corneal infection.
Dr. Charles Slonim, a USF clinical professor and ophthalmologist, said college students are more likely to make these types of errors due to their tight budgets and unwillingness to throw out items that “still work.” He compared the expiration date of a contact lens to that of a disposable razor.
“People often use razors to the point where they can’t be used anymore — you often throw it out once it cuts you,” he said. “Then you know it’s no longer good. You don’t have that option with contacts. Once you get to the point where it hurts, it could be too late.”
And complications do occur, if only to a small fraction of contact lens users.
Slonim said one patient treated at the Carol and Frank Morsani Center for Advanced Healthcare, woke up one morning with tremendous pain in her left eye after sleeping while wearing her extended wear contact lenses the night before.
The contacts prevented oxygen from reaching her eyes, Slonim said. The patient developed blood vessels which grew in from the white of her eye into the center. She now needs a corneal transplant.
“Although her vision could be improved with the transplant, it will always be impaired,” he said.
Extended wear lenses are more oxygen permeable than daily-wear lenses, which make them safer for sleeping with. However, even with oxygen-permeable lenses, the oxygen level reaching the eyes is relatively low.
“There’s no question that they’re safe,” Slonim said. “But every night you sleep with them in, the higher the risk of corneal infection.”
Anderson and Slonim said sleeping with extended wear contacts isn’t the only misuse to be careful of. Mismanagement of disposable and daily-wear contacts can be just as devastating. Because these lenses aren’t made for sleeping, and there is much less oxygen permeability, the risk of complication is substantially higher.
Other methods of mismanagement, such as cleaning lenses inadequately or using contacts past the expiration date can also be harmful.
“Make sure you follow the manufacturer’s recommendations,” Anderson said. “Make sure if you’re supposed to throw it out by a certain date, you throw it out. Make sure if you re-use a lens, that it is cleaned properly.”
About 32 million Americans, or 12 percent of the national population, wear contact lenses.
Eye-care professionals emphasized the fact that contact lenses are perfectly safe and a great substitution for surgery or conventional glasses, as long as they are used with caution and cared for properly.