Institute ortho-K in your practice armed with the right tools, the right training

Issue: October 1999

There have been so many advancements in both the contact lens arena, particularly disposables, and the refractive surgery sector — more optometrists than ever are comanaging photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) patients — that many practitioners may not give serious thought to orthokeratology (ortho-K). With such a wide range of cutting-edge options available to correct or reduce myopia, why should an optometrist consider ortho-K?

Todd Winkler, OD, in private solo practice in Cincinnati, said that, while many suitable refractive surgery candidates will simply opt for a permanent correction through surgery, he advocates ortho-K for certain active contact lens wearers and those wary of undergoing surgery.

“If patients want to go swimming, drive a race car or fly a plane, and they wouldn’t feel comfortable wearing their contact lenses for those situations, they can remove their contact lenses on an as-needed basis,” he said. “A patient may come in and say that he loves his contact lenses, but they’re really a pain when he goes water-skiing. A couple of my patients who are pilots wear their ortho-K lenses all the time, but it just gives them an added sense of security that should a lens pop out, at least they know that they can see clearly for a few hours. If the prescription falls within an acceptable range, I suggest that a patient may want to consider ortho-K.”

Ortho-K is one option that can be presented to patients with low myopia. “One route might be to go to soft disposable lenses,” said Rodger T. Kame, OD, in private group practice in Los Angeles. “The other would be to go to rigid gas-permeable lenses (RGPs) in hopes of slowing down the progression of myopia. As an option, then, we would talk about orthokeratology as a means to improve vision, not only while the lenses are on, but after their removal.”

Instrumentation: the tools for ortho-K

Most of the instruments a practitioner would need to incorporate ortho-K into the practice are already in his or her office, such as a keratometer and a slit lamp, said Dr. Winkler. “Some practitioners have corneal topographers, which are very nice,” he said. “They are not necessary, but they can provide more detailed information about the cornea and changes in the corneal curvature.”

More than a benefit, Dr. Kame said that a topographer is a necessary tool that serves many purposes in an ortho-K practice. “It enables you, most importantly, to monitor the changes taking place in the eye,” he said. “So, the management of the patient, clinically, is benefited by having a topographer. Secondly, it helps you understand the lens design with which you’re working, in that there are programs that design lenses off of the corneal topography. It is most appropriate for monitoring changes in an orthokeratology patient. Use of the topographer is good for patient understanding and management — they get an appreciation for the technology that’s being used to demonstrate the changes happening.”

However, a practitioner who does not yet have a topographer can still provide ortho-K with the instruments he or she already has, Dr. Kame agreed. “Practitioners can still do keratometry and get some sense of what’s happening to the eye,” he noted. “Above all, I think they need to look closely with the slit lamp to make sure they’re not disrupting the epithelium or the surface of the eye. The usual principles of maintaining good, healthy corneas are still very important.”

Seek education

To expedite the indoctrination into ortho-K, Dr. Winkler suggested some research and education for practitioners serious about incorporating it. “I’d recommend, above anything else, that they contact the National Eye Research Foundation (NERF), because it has many continuing education courses and materials available to help a practitioner who’s just beginning in ortho-K,” he said. “That’s the best thing to do. That’s how I got started in ortho-K, and NERF was just wonderful. It has continuing education seminars located throughout the country delivered by top-notch practitioners — some of the pioneers in ortho-K who made a lot of breakthroughs.”

Reverse geometry for faster results

The practitioners recommended reverse-geometry lenses for ortho-K patients, because they bring about the flattening effect for faster changes than traditional rigid lenses.

“The term ‘reverse geometry’ means that the shape of the lens is in reverse, so with the fitting principles, you have to reverse your thinking,” Dr. Kame stated. “That’s where practitioners have to become familiar with the accelerated process. When you make a diameter change in the reverse-geometry lens, it dramatically tightens the lens, whereas it has very little influence on a regular lens. Or as in regular ortho-K, decreasing the optical zone size flattens the lens. When you do that with a reverse-geometry lens, you are steepening the lens.”

Dr. Winkler, who uses lenses by Contex (Sherman Oaks, Calif.), said that several companies today manufacture this type of lens. He explained that, rather than the flatter radius of curvature in a typical RGP, the flat central portion of the reverse-geometry lens surrounded by a steeper secondary curve helps achieve results more quickly. “You can bring about faster changes with reverse-geometry lenses; it really cuts down on the length of time it takes to reach an endpoint,” he noted.

Embarking on daytime wear

Dr. Kame recommended beginning the process with a regular spherical lens to help the patient grow accustomed to wearing rigid lenses, build up a wearing cycle, establish a regimen and monitor the adaptation process. “That way, practitioners would have already established a certain level for the patient that they can always go back into if orthokeratology doesn’t work well,” he said. “At the same time, it provides the practitioner an opportunity to learn about the nuances of ortho-K fitting in daily wear using reverse-geometry lenses.”

Ortho-K is more effective in patients with lower myopia, said Dr. Winkler. “Those patients are really good candidates for ortho-K,” he said. “They can take their lenses out and go for hours and hours with nice clear 20/20 vision. Once you get up to a certain point, into the higher prescriptions, the ortho-K effect is less successful.”

Once a patient grows accustomed to wearing such lenses, Dr. Kame said, the wearing time is increased to the point where a patient – it is hoped — will have 20/20 vision. By wearing them for a solid 8 to 12 hours during a 24-hour period early on and removing them in the evening, the patient can then begin to reduce the wearing time to realize the maximum benefit, he said.

“They start to taper off the wearing time so the goal might be to wear them for 4 to 6 hours,” Dr. Kame suggested. “That’s where the learning would take place; you would have the patients remove the lens earlier and earlier, and you would monitor how they’re responding to that.”

Should you venture into overnight wear?

Although overnight wear of ortho-K lenses has not been given the green light by the Food and Drug Administration (FDA), it is the most efficient use of ortho-K, stated Dr. Kame. Until it receives approval, he said, the most effective way to learn about this aspect of the process is to participate in laboratory studies.

“I inform patients that we have ortho-K in two modes and that the overnight wear is the one that I prefer, but the only way it can be done is with studies and they have to sign a consent form,” he said. “That way, they know it’s under study. That’s why I don’t do a lot of them, but I do enough to feel comfortable with it to offer it as an option to my contact lens patients.”

While Dr. Kame feels comfortable giving patients the option of overnight wear, FDA approval is needed before it truly can be promoted. “Until the studies validate that, we can’t be encouraging people to do it,” he stated.

Marketing the concept of ortho-K

Dr. Winkler said that, while some practices will advertise ortho-K externally, he prefers to take a more internal approach based on the needs of each particular patient. “I don’t promote it that heavily in the practice, but I sit down with each patient and I ask what brings him or her in and if he or she is interested in contact lenses,” he said. “Based on the responses, if I feel the patient is a good candidate for it, I can present that as an option.”

Dr. Kame, who relies mainly on mentions in his Web site and word of mouth for marketing ortho-K, said that he might be more aggressive in advertising the concept once overnight wear receives FDA approval. Whatever approach a practitioner may take toward marketing, however, he stressed the importance of making patients aware of this alternative to refractive surgery. “For those who need to reduce their uncorrected vision to pass certain visual requirements, orthokeratology is a nice way to do it — especially for circumstances where refractive surgery is not allowed,” he added.

He conceded that while ortho-K may be losing some of its demand due to the rising popularity of LASIK, many patients who are hesitant to make a permanent change may be attracted by the reversibility of the process. Once the FDA approves overnight wear, an even stronger case may be made, he added. “I have a feeling that if the FDA’s blessing is there, and people are applying orthokeratology to overnight wear appropriately, it’ll get very good results,” he said.

For Your Information:

Rodger T. Kame, OD, FAAO, is a member of the Editorial Board of Primary Care Optometry News and is in private group practice in Los Angeles. He may be contacted at 250 East First St., Ste. 802, Los Angeles, CA 90012-3875; (213) 628-7419; fax: (213) 620-9110. Dr. Kame has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

Todd Winkler, OD, is in a private solo practice in Cincinnati with an emphasis on contact lenses. He may be reached at 11700 Princeton Pike, Cincinnati, OH 45426; (513) 671-5020; fax: (513) 671-6852; e-mail: Twiy@aol.com. Dr. Winkler has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.