EDITOR'S PERSPECTIVE

By Joseph T. Barr, O.D., M.S., Editor

RGPs and Our Need to Know

Do we devote too much ink to RGPs in Contact Lens Spectrum? During a recent lecture, an expert RGP lens prescriber told me he thinks we do. I appreciated his comments and made note of his suggestions on what we should cover in the soft contact lens area.

On another occasion, however, the owner of a large RGP lab told me that many practitioners still order RGP lenses by only base curve, power and diameter, and that many of the people who place these orders have no idea of what an optic zone or a peripheral curve is. He said the largest and most successful practices understand lens construction, fluorescein pattern interpretation and the cause-and-effect relationships of lens modifications.

I'll bet 80 percent of RGP lenses are ordered by 20 percent of practitioners (the 20 percent who know about lens design and inspection and the subtleties of lens prescribing and modification) and are sold by labs who know how to best manufacture, polish and inspect a lens.

That said, there's nothing like a real-life scenario to bring it all home.

Not long ago, I examined my sister and her RGP lenses. She wears them nearly all day and has worn RGPs for about 30 years. Her chief complaint was difficulty reading. I also examined my brother-in-law and prescribed new occasional wear disposable lenses for him.

Since my sister and her husband are in their fifties, we had a frank conversation about the need for reading glasses over their contact lenses, or monovision or bifocal contact lenses. I told my sister that if she didn't like reading glasses and if monovision had failed, then it was time for progressive addition RGPs. I told her they're good for computer use, good at intermediate distances and they work in all directions of near gaze, but there may be some variable vision especially peripherally.

"No," she said, "I don't need those yet." I looked at my brother-in-law and said, "It's tough to prescribe for a big sister. I thought I was the doctor here." To this my sister said, "The last time I was here, we just changed the power of these lenses and I could read."

Sure enough, I reviewed the record and saw that we had added some plus then (her myopia is reducing) and she had liked the result. I overrefracted her lenses and she was right. We prescribed +0.75D more OD and +0.25D more OS and she loved her vision at near and at distance. I told her she'd still need her reading glasses, and that she might need multifocal lenses in a couple of years. She ordered some new PAL spectacles for reading at night, too.

My brother-in-law asked if he could get multifocal contact lenses. I told him that he wouldn't do as well with them since he preferred only part-time contact lens wear, and that the type of lens I wanted for my sister in the future was more successful for full-time RGP wearers.

These RGP stories point out how the very nature of a rigid lens requires that practitioners have a lot more smarts for prescribing success than they need for soft lenses . . . which is why we regularly publish articles about RGPs. CLS