A Favorable Horizon for Overnight Lens
BY JOSEPH T. BARR, OD, MS, FAAO, EDITOR
Public statements at the end of last year indicating that
hyper-Dk lenses used for overnight or continuous wear didn't decrease the incidence of infectious keratitis compared to
low-Dk lenses weren't encouraging. And recent reports of corneal ulcers in children who wore corneal reshaping lenses overnight for myopia reduction were concerning. It seems that by far, the majority of people who sleep with lenses on their eyes are safe from corneal ulcers while perhaps one in 500 aren't. What's different about the one in 500? Is it their immune system? Can't they defend themselves against the bad bugs?
The good news is that most contact lens wearers who wear new silicone hydrogel and
hyper-Dk GP lenses are safer than ever. They experience fewer corneal problems such as edema, epithelial
microcysts, polymegethism, neovascularization and ocular bulbar and limbal injection. They probably have clearer vision and perhaps even less dry eye symptoms in many cases. We also know that young males and patients who've exposed themselves to pathogens by swimming and then sleeping with their lenses on, those who've had previous acute red eye reactions and those who have dry eye are bad candidates for continuous wear. And certainly if a child or adult is going to apply a lens at night -- no matter how high the
Dk/t -- for myopia reduction purposes, then that lens should be as clean, disinfected and biocompatible as possible.
But as Rex
Ghormley, OD, FAAO, points out in this issue in his Contact Lens Materials column, even if you aren't recommending overnight, flexible, extended or continuous wear, you should know that many of your patients frequently sleep with their lenses on even if they are daily wear patients. So use the lenses with the highest
Dk/t, most of which are the new silicone hydrogel lenses, whenever you can. More specialty lenses will become available in these materials this year, with some entering the market for astigmatism even as we publish this. Some of you are reluctant to change your habits and continue to prescribe your favorite hydrogel lenses because of habit, perceived price point issues or even the belief that the
hyper-Dk/t lenses aren't perfect yet. Sure, a few patients have experienced problems with them, but those patients are by far a minority. Go for it, my friends -- daily wear and an occasional nap or sleep with these new lenses is the way to go.
Contact Lens Spectrum, Issue: March 2005