I have a 15 year old patient who plays competitive water polo and spends nearly every day wearing contact lenses in a chlorinated swimming pool. Although I recommended swimmng goggles he prefers not wearing any, and he and his coach were wondering what contact lens material would minimize chlorine uptake. He has been wearing Acuvue 2 contact lenses, and I am having him try Acuvue Advance contact lenses. Would the chlorine uptake in water, and from chlorine gas above the water, be any different in Acuvue Advance or another silicone hydrogel than a HEMA contact lens?

Very few published studies exist to specifically look at the uptake of chlorine into hydrogels, but the molecular weight is significantly less than chlorhexidine (about 9 times smaller), so uptake will likely be substantial. Despite this, the only published work thus far seems to indicate that swimming with lenses on may actually provide some protection from eye irritation induced by chlorine. Solomon found that swimmers who wore their lenses when swimming had substantially less corneal staining and improved comfort over those who removed them. However, 15% of subjects lost their lenses during the course of the study!

The likelihood is that the uptake of chlorine into conventional and silicone hydrogel materials will not be substantially different. However, we would caution against swimming in contact lenses without goggles, not only to limit the uptake of chlorine but also to minimise eye infections. Many of the early cases of microbial keratitis with overnight use of silicone hydrogels occurred in patients who wore their lenses when swimming, presumably due to pathogens attaching to the lens material. We suggest that all continuous wear patients who swim in their lenses (even with goggles) complete a full disinfection cycle with their care system after swimming, and before the lenses are worn overnight. Our preferred methods are: cleaning and disinfection using a peroxide system with a 4 to 6 hour soak before wear or, thoroughly rubbing and rinsing lenses with a multipurpose solution followed by a 4 to 6 hour soak in fresh solution before wear.

We would recommend a high Dk silicone hydrogel lens for daily wear with close and regular follow up to minimize the chance of any changes to the cornea going unnoticed.

References:
Solomon J: Swimming with soft lenses. Contact Lens Forum 1977; 2 13-5.
Solomon D: Hydrophilic lenses for swimming. Contact Intraoc Lens Med J 1979; 4 93-4.
Holden BA, Sweeney DF, et al.: Microbial keratitis and vision loss with contact lenses. Eye Contact Lens 2003; 29;1 Suppl: S131-4; discussion S143-134, S192-134.