Piggybacks offer comfort, quality of vision

"A piggyback system is easy to try in your office," Dr. Malooley said. "Patients can give you immediate feedback, and they're usually very impressed by the comfort and quality of vision piggybacks provide. Plus, they typically are able to continue using their current RGP lens."

Fitting patients with piggyback lenses isn't difficult, he added. "You just use the basic principles of reading fluorescein patterns, as we do with normal RGPs, and extrapolate those to the lenses used."

Dr. Malooley noted that optometry schools have traditionally taught students not to use fluorescein staining with soft lenses, but disposable lenses have diminished that concern.

"Back when patients kept their soft lenses for a year, you didn't want to put fluorescein on them, but that's not much of an issue today," she said. "However, if you're still concerned about using fluorescein with soft lenses, you can always read the fluorescein pattern of the gas permeable lens on the cornea and then add the soft lens and look for different characteristics to see if it's a good fit as well."