Study claims RGPs may slow childhood myopia

New research from the US suggests that rigid gas-permeable contact lenses may help slow the progression of myopia in young children.

At the end of a three-year study of more than 100 eight to 11-year-olds, US researchers determined that wearing rigid gas-permeable (RGP) contact lenses slowed the progression of myopia by nearly 30 per cent, compared to soft contact lens wear.

Jeffrey Walline - the study's lead author and an adjunct assistant professor of optometry at Ohio State University - and colleagues caution that the RGP lenses will not stop myopia but claim that the lenses could be a good option for nearsighted children who can adapt to wearing them.

'Severe myopia, which is fairly rare, can lead to a detached retina and permanent vision loss or glaucoma,' Walline said. 'Theoretically, wearing RGP lenses could lessen the severity of myopia, and likewise the chances of developing one of these problems. '

The study is published in the December 2004 issue of the journal Archives of Ophthalmology.

The researchers evaluated 116 children who were all given about two months to adapt to wearing the rigid contact lenses before the study officially began.

At the end of the two-month initiation period, children were randomly assigned to wearing RGP lenses or two-week disposable soft contact lenses. Children returned to the optometry clinic each year for three years for vision checkups.

'To have a permanent effect, contact lenses would ideally control the shape of the eyeball as it grows,' Walline said. 'The RGP lenses did not do that. However, they did change the shape of the cornea on a short-term basis.'

Soft contact lenses had no effect on the shape of the cornea, or on the progression of myopia.

The children in both contact lens type groups wore their lenses an average of 70 hours a week. However, the researchers were not sure how many hours a day a child would have to wear RGP lenses in order to slow the progression of myopia.