contact lens business
Choosing the Right Disposable
With more options available every year, these contact lenses offer something for almost everyone.
By William Ehlers, M.D.

Acuvue, the first disposable lens, was introduced in 1987, and the contact lens market has never been the same. Of the 34 million contact lens wearers in the United States, more than 14 million (46%) currently wear disposable lenses.

In addition to the "standard" spherical lenses, disposable lenses are now available for the correction of presbyopia and astigmatism -- even in colors. At the same time, the new silicone hydrogel lenses, approved for 30 days of continuous wear because of their excellent safety profile and high oxygen permeability, have made disposable lenses an option for even more individuals.

Sometimes, when matching a patient to a lens, the choice is obvious; sometimes several lenses would work. For example:

Young patients with low-level refractive needs. A 25-year-old with moderate myopia and less than 1 diopter of astigmatism will probably do well with just about any disposable lens, including tinted lenses. Most lenses will mask this amount of astigmatism.

Astigmats. Astigmatism greater than 1 diopter usually requires correction by a toric lens for best acuity. Toric lenses are available in 2-week daily wear, 1-week extended wear and daily disposable versions. The parameters available are limited, however, with cylinder powers ranging from -0.75 to -2.25 and the axis at 90 and 180 the most common offerings. Check the manufacturers' literature and Web sites, or Contact Lens Quarterly for the most recent parameters.

Presbyopes. These patients have a number of options:

► Monovision can generally be accomplished using any disposable lens. Typically, the dominant eye is corrected for distance and the non-dominant eye is corrected for near. However, individuals with a personal preference or occupational need for better near vision may prefer having the dominant eye corrected for near work.

Monovision generally works better for early-to-moderate presbyopes, when the disparity between near and distance correction isn't too great. Some individuals may do better with a bifocal lens in one eye and a single vision lens in the other.

► Bifocal lenses are a good option for those who can't tolerate monovision. (However, monovision may be the only disposable option for a presbyopic patient with significant astigmatism.) Patients whose needs match the available parameters can choose from disposable bifocal lenses for 1-week extended wear, 2-week replacement, and daily disposable wear. Progressive adds are available to +3.00.

Patients with contact lens-related problems. Problems related to lens coating, such as giant papillary conjunctivitis, or lens irritation can be solved by switching to a lens with a shorter replacement interval. If the problem is related to hypoxia, such as corneal neovascularization or peripheral infiltrates, switching to a high dK silicone hydrogel may solve the problem.

Infrequent wearers. Many patients may only want to wear contact lenses for special occasions. Others may be interested in them for use in sports. These occasional wearers are ideal candidates for daily disposable lenses.

Only the Beginning

Remember that many would-be lens wearers have been told that they can't wear lenses. Be sure your staff and patients are informed about the new options. Given the advantages of these lenses -- including safety, convenience, and choice of modalities -- their popularity is sure to keep increasing.

Dr. Ehlers is associate professor at the University of Connecticut Health Center in Farmington, Conn., and president of the Connecticut Society of Eye Physicians. He is on the board of directors of the Contact Lens Association of Ophthalmologists and the Joint Com-mission on Allied Health Personnel in Ophthalmology.