Worldwide use of extended wear contact lenses that are worn continuously for several days remains low, according to a new study.
In a report published in Optometry and Vision Science,* researchers in Australia evaluated contact lens fittings performed in 39 countries over a 14-year period (1997 through 2010). The study data suggest use of extended wear (EW) lenses peaked in 2006, when approximately 12 percent of all contact lens fittings performed in the countries surveyed were for extended wear.
In 2010, worldwide use of EW lenses accounted for just 7.8 percent of contact lens prescriptions, with usage being highest in Norway (27 percent). Approximately 10 percent of contact lenses worn in the United States in 2010 were extended wear lenses.
The researchers also found that most people using extended wear contact lenses also purchased contact lens solutions, suggesting that many wearers might be removing their lenses occasionally and sleeping without them on rather than wearing them on a continuous basis for the lifetime of the lenses, which typically is 1-2 weeks or monthly.
The study also revealed that 72 percent of extended wear lenses were silicone hydrogel contact lenses, which allow significantly more oxygen to reach the front surface of the eye than regular soft (hydrogel) lenses and therefore are considered by many eye care professionals to be safer for continuous wear.
The study authors noted that the risk of eye infections remains significantly higher when contact lenses are worn overnight compared with when lenses are worn on a daily wear basis (removed before sleep), and that extended wear lenses are unlikely to gain mainstream use until “the already low risk of ocular complications (from EW) can be reduced to be equivalent to that of (daily wear).”
*International survey of contact lens prescribing for extended wear. Optometry and Vision Science. February 2012.
Tags: extended wear contacts
