Ortho-K
A Bright Idea
Why and how orthokeratology can benefit your patients and your practice.
By John M. Rinehart, O.D., F.A.A.O., and James W. Reeves, O.D., F.I.O.S.

ILLUSTRATION BY ANTHONY CERICOLA

Orthokeratology (ortho-K) got its start about 40 years ago when practitioners Charles May, O.D., and Stuart Grant, O.D. used large-diameter lenses fit flatter than "K." The process, fitting and follow up took months and many lenses to reach the desired results.

Since then, the development of reverse geometry lens designs (a lens that has one or more intermediate curves with a steeper radius of curvature than the base curve), high Dk gas permeable materials and computerized corneal topography have led to an orthokeratology renaissance. These developments provide added safety, especially for night wear, and greater degrees of myopia reduction. Modern accelerated orthokeratology typically uses only one pair of lenses to reduce up to 4.50D of myopia and reaches maximum results within a few weeks instead of months.

Providing a rewarding alternative

Ortho-K is a viable option for low to moderate myopic patients who want less dependence on their glasses or contact lenses or would like improved unaided acuity.

Patients are attracted to ortho-K because it has no age restrictions; it's reversible and carries none of the risks of surgery. We know that ortho-K can reduce myopia; currently, studies are underway at Ohio State University investigating whether ortho-K also slows or stops myopic progression.

The thrill of greeting an excited patient who's seeing 20/20 unaided (or close to it) after a first night of using ortho-K never diminishes. And if that's not reward enough, using this technology on your patients can also boost your bottom line.

Professional fees can range from $1,000 to $3,000; lens cost typically is about $50 per lens. If we assume a fee of $1,500 and a lens cost of $200 (total of 2 pair of lenses), the gross profit is $1,300 per patient.

Using these numbers, the chart above demonstrates the annual financial impact on your practice of adding one new orthokeratology patient per month, per week or adding 2 per week.

What you'll need

A topographer, whether in your office or readily available somewhere else, is mandatory. You need it to be sure that the cornea is free of abnormalities, such as keratoconus. Also, you need to know the shape of the cornea before beginning therapy so you can evaluate the changes created by treatment. Other instruments you will need are:

• 14 to 24 diagnostic lens set.
• lens diameter gauge, to verify lens diameter.
• hand-held magnifier with reticule, to measure the widths of the various zones on the lens.
• thickness gauge, to measure center and edge thickness.
• lensometer, to verify the lens power and assess the quality of the lens optics.
• radiuscope, to verify the base curve radius and assess the quality of the base curve optics.
• edge analyzer, to assess the contour of the lens edge.
• yellow Wratten filter, to enhance the fluorescein pattern evaluation.
• lens modification equipment to perform the following:

• resurface (polish) the front and back surfaces of the lenses
• make power adjustments
• recontour edges
• modify the lens fit by making changes in or near the peripheral curve.

Know your stuff

Here are pointers about learning to deliver ortho-K.

You must receive comprehensive training in the lens design(s) you intend to use. The lens designer and/or the lab manufacturing the lens should provide training, which should consist of the basic principles of ortho-K therapy.

It's helpful to have a good understanding of how the lens is designed, i.e., how the curves are determined. This understanding is most beneficial for problem solving, when it's necessary to modify the fit to improve the results. Never disregard sound gas permeable lens fitting principles for the sake of reducing myopia.

Consultation and support should be available after the training. Don't be totally dependent on the trainers or laboratory(s) to fit or refit the patient, but both are good sources for consultation.

To best take advantage of their knowledge, ask why they're recommending a specific design change. The better you understand the fitting process, the better orthokeratologist you'll become.

Learn quickly. Generally, you should arrive at a good level of comfort once you've treated 3 to 10 patients, depending on your degree of expertise fitting gas permeable lenses, the quality of your training and the level of difficulty involved in fitting the lens design you're using.

Keep current. As technology improves, so will techniques and instruments.

Many of the larger national continuing education meetings (including Southeastern Council of Optometry [SECO], Great Western Council of Optometrists (GWCO) and the American Academy of Optometry [AAO]) provide lectures on ortho-K. These offer an opportunity to update your knowledge and learn the newest techniques and theories of ortho-K.

Choose wisely

Once you've learned about what you'll need and how to perform the therapy, pick your patients. Here are some guidelines:

• Make sure the patient is in good health, both general and ocular.
• Clear up any ocular surface disease and meibomian gland dysfunction before beginning ortho-K on any patient.
• Age is seldom a consideration in ortho-K, but the patient must have the dexterity to handle lenses and the commitment to properly maintain them.
• Patients who have up to -4.50D of myopia and less than 1.50D of with-the-rule (WTR) astigmatism are good candidates. It's best if topography shows that the astigmatism is confined to the central 2.0 mm to 2.5 mm of the cornea.

You can expect to reduce approximately 50% to 60% of WTR astigmatism. Inform patients who have against-the-rule (ATR) astigmatism greater than 0.75D that you don't expect ortho-K to reduce this form of astigmatism and that as a result, their vision improvement may not be as great as they desire.

Also consider the potential for residual astigmatism. Patients may find this annoying, so counsel them about the possibility before initiating therapy.

• Discourage patients who have large pupils (> 6.0 mm) from having ortho-K because they'll probably experience ghost images at night.
• Corneal eccentricity (the rate by which the cornea flattens from apex to periphery) may be a factor in predicting the amount of change you can expect.

In general, the greater the eccentricity, the greater the amount of refractive change. One estimate is that for each diopter of change there must be 0.21 eccentricity. For example, a 3.00D myope must have an "e" of at least 0.63 to reduce all myopia.

• Devote time to informing the patient of the advantages as well as the limitations of ortho-K. Present the limitations in a positive light. The fact that ortho-K isn't permanent isn't a negative; rather, reversibility is an advantage.
• Ortho-K doesn't compete with refractive surgery -- it presents an alternative to extended wear contact lenses.
  Patients seeking refractive surgery generally want freedom from contact lenses and this isn't going to happen with ortho-K. Ortho-K is a viable option in lieu of extended wear contact lenses. The patient will be free of lenses during his waking hours, with only minimal lens adaptation.
• When first presenting ortho-K to the patient, impress upon him that it's a time-consuming process. His lifestyle must allow him the time for the required follow-up visits.

Promoting within legal limits

When advertising ortho-K, don't make unsubstantiated claims. According to the Federal Trade Commission's Advertising Guidelines for ortho-K, you must have actual statistics to back up your claims of success. Generally, testimonials aren't a good method of promotion because the results may not be typical of a general population. Also, don't make exaggerated or easily misinterpreted statements in any of your advertising.

In its notification dated September 1998, the Food and Drug Administration states, "A licensed practitioner may individually design and prescribe an RGP orthokeratology lens for a particular patient within the scope of his/her practice." It continues, "However, eyecare practitioners who promote orthokeratology in their practice should avoid exaggerated and unsupported claims of safety or effectiveness. Promotional material should include accurate, well-balanced statements explaining that the effect of these lenses is temporary and limited."

Spreading the excitement

All of your staff members should have a good understanding of ortho-K's goals and limitations. They should be able to intelligently answer questions about how it's practiced in your office. You can include in-office training in your regular staff meetings or present it in writing. Staff members should also be enthusiastic about ortho-K and convey that excitement to patients. Patients love to hear comments about how well the procedure is working -- it reinforces your endorsement.

Rewarding to all

Ortho-K is an exciting field of optometry. You must be committed to understanding the procedure and how best to manage your patients. With proper training and experience, you can offer your low to moderately myopic patients a treatment option that's rewarding to both them and yourself.

In the future, we'll tell you more about materials, lens design and training.

Dr. Rinehart is in private practice in Peoria, Ariz., and has been lecturing on orthokeratology since 1996. Dr. Reeves is in private practice in Great Falls, Mont., and has lectured on ortho-K since 1999. Both doctors are graduates of Pacific University of Optometry and have been performing accelerated ortho-K since 1995.