As we enter 2024, the GP Lens Institute plans on introducing a number of new resources and programs to help both the novice GP fitter and students including our “I Have a GP Wearer in My Chair: What Do I Do” module, and a “SWAG bag" of resources for student members. In addition, our staff module is currently being revised and expanded to include several of the WINK Productions programs and we will introduce case-based GPLI “Eye Rounds”. Look for new programs from our exceptional Myopia Programs and Resources Committee now chaired by Dr. Langis Michaud.

In this newsletter, we will highlight an exceptional webinar on keratoconus and cross-linking by a foremost expert in this area – and the 2023 recipient of the GPLI-NKCF Thomas J. “Tommy” Pham Keratoconus Practitioner of the Year Award – Dr. Clark Chang. Our 2024 webinar series is highlighted as well with the likely addition of a “bonus” webinar for members and non-members on coding and billing from the expert in this area, Dr. Clarke Newman. Members can view the new edition of The Advisor which includes a series an excellent clinical articles under the theme of “The Business of Specialty Contact Lenses”. Likewise, the December issue of “GPLI Radio with Dr. Tom Quinn” focuses on the contact lens management of astigmatism with Dr. Matt Lampa.

This conversation is with Matt Lampa, OD, Professor at Pacific University College of Optometry where he is involved with specialty contact lens fitting, contact lens instruction, and clinical research. He is also an associate in a private practice in Silverton, Oregon and a member of the GPLI Advisory Board. Key takeaways included:

Why discussing regular astigmatism is important

• Commonly encountered
• There are so many options for correction
• Often these patients struggle; if you can recognize the reason and get them successful you will have a very loyal patient

The “flinch level” of astigmatism

• 0.75 D of astigmatism
• Up to one-third of contact lens candidates
• Important to consider in the plane of the cornea
• When vertexing high minus, astigmatic error goes down
• When vertexing high plus, astigmatic error goes up

Things to consider when choosing the contact lens modality to employ to correct regular astigmatism

• Amount of astigmatism
• Patient’s prior experience with contact lenses
• If problems with a prior modality, more open to consider other options

Tips for soft lens correction of astigmatism

• Masking doesn’t work
• Today’s toric soft lenses perform very well
• Bias astigmatic correction down if necessary
• Assess centration, orientation and axis stability

When to consider a toric corneal GP

• If the major meridians differ in height by 40-60 microns, consider a toric design
• Usually around 2 or 2.5 D of corneal cylinder
• If unsure, place a sphere on the eye and assess stability
• Spherical Power Effect (SPE) designs can rotate on the eye without visual blur
• Cylinder Power Effect (CPE) designs will lead to blur if rotated on eye

Scleral lenses and regular astigmatism

• Little correlation between corneal and scleral toricity
• If finding astigmatic error in over-refraction
• If flexing:
• Improve fit?
• Increase center thickness
• If no flexure:
• Incorporate astigmatic correct into contact lens
• Over spectacles

Hybrids and regular astigmatism

• Can be a good option if corneal and refractive astigmatism match
• Center thickness can be increased (enhanced profile)

When in doubt, utilize your laboratory consultant

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