An Australian study reveals that the contact lens-related corneal infection rate is 4.2 per 10,000 wearers per year. The researchers wrote that their study is the first to describe the incidence of infection associated with the two new types of lens introduced with the expectation of reduced risk of disease — daily disposable soft lenses in 1995, and silicone hydrogel lenses in 1999.
Planned replacement soft lenses are safer for the eyes. The new types of lenses were aimed at reducing the impact of corneal hypoxia, which may increase corneal infection.
The research was done by the researchers in the Moorfields Eye Hospital in London and was led by the John K. G. Dart, D.M.
The Australian team's prospective, 12-month study looked at microbial keratitis cases reported at ophthalmologists' offices and via a randomly selected population-based telephone survey. Data were collected for 35,914 individuals, 1,798 of whom were contact lens users. The researchers however, find that overnight use of the lens increases risks of eye disease.
The new age soft lens, Silicone hydrogel lens users who kept their lenses in overnight had the greatest disease incidence at 25.4 (95% CI 21.1 to 31.5) per 10,000 wearers per year. Overnight use of regular soft lenses had the second greatest annual incidence at 19.5 (95% CI 14.6 to 29.5).Although vision loss was rare — seen in 9.9% of all cases, or 0.4 per 10,000 wearers overall — risk was also associated with overnight use, the researchers said.
However, the researchers have found that overall, when used properly, daily disposable lenses were associated with the lowest risk of severe disease. They wrote, Eliminating the contact lens storage case may reduce the likelihood of lens contamination by Gram-negative bacteria, which is associated with more severe disease.
Although the risk of disease was higher overall in daily disposable lens users, risk of vision loss was less than it was among planned replacement soft contact lens users (P=0.05), the researchers said.
Source: Med Page Today
Filed under Contact Lens, Eye Care Products, Eye Treatment | Tags: corneal infection, daily disposable lenses, daily disposable soft lenses, eye, Gram-negative bacteria, Keratitis, Microbial Keratitis, replacement soft lenses, silicone hydrogel lenses | 1 Comment