Contact Lens Case Reports

The Evolution of Corneal GP Prescribing

BY PATRICK J. CAROLINE, FAAO, & MARK P. ANDRÉ, FAAO

This month’s case involves a 26-year-old myopic female who had a small amount of regular, with-the-rule astigmatism. The patient presented with no history of contact lens wear, and we subsequently fitted her with 9.5mm corneal GP contact lenses. At her recent follow-up visit, she was comfortably wearing her lenses for 14 to 16 hours a day with 20/15 visual acuity.

So ... what’s wrong with this case? The answer: absolutely nothing. Except that she represents a disappearing breed of contact lens wearers.

Today’s Corneal GP Market

Today, we believe that the corneal GP contact lens market can be divided into four fairly distinct categories (Figure 1). Category #1 comprises the normal myopes and hyperopes who have low-to-moderate regular astigmatism. Category #2 consists of higher astigmats who have failed with toric soft lenses and have found success with GP designs. Category #3 represents those who require special optical applications, such as orthokeratology and presbyopic optics. Category #4 consists of those individuals who have irregular astigmatism secondary to corneal injury, surgery, or disease.

Figure 1. The categories of corneal GP lenses.

Now, back to our case. Our patient clearly fell into Category #1. As practitioners who have 35 years of lens fitting experience, we have the knowledge and confidence to recommend GP lenses for this patient. But will today’s new practitioners be fitting Category #1 patients with corneal GP lenses?

Feeling the Generation Gap

There appear to be three fundamental obstacles that we, as an industry, have been unable to overcome with our new generation of contact lens practitioners. First, despite our best efforts, optometric educators (ourselves included) have been unsuccessful in teaching our students the fitting and follow-up skills needed to succeed with GP lenses. Second, our younger colleagues come from a generation that is reluctant to fit any modality in which adaptation is required. And third, the industry has failed to recognize and acknowledge these critical, generational differences. It is important to recognize that these factors are not new to our industry and have been constantly evolving for the past two decades.

Our impression is that younger colleagues are less likely to embrace corneal GPs for Category #1 patients. Additionally, with toric soft lens designs continually expanding and improving, the number of GP patients in Category #2 will continue to diminish. We believe that Categories #3 and #4 will remain viable.

Today, corneal GP lenses serve an important role in the specialty contact lens practice, and there will always be a handful of well-trained practitioners to carry on the corneal GP legacy. However, as a functional modality for normal eyes, we’re afraid that when our generation retires ... that modality retires with us. CLS

Patrick Caroline is an associate professor of optometry at Pacific University. He is also a consultant to Contamac. Mark André is an associate professor of optometry at Pacific University. He is also a consultant to CooperVision.