GP insights

Building Your GP Practice

GP insights
Building Your GP Practice

Some practitioners fit all patients with soft lenses. But soft contact lenses are not best option for all patients. Many practitioners do not fit GP lenses because of limited time, less-than-optimum experience and confidence or both.

Why build your GP practice? It will bring you professional satisfaction, and your patients deserve it. Here's how to start.

Boosting GP Confidence

If you do not fit GP lenses because you lack the confidence or experience to do so, I recommend that you foster a good relationship with your GP lens laboratory. Most labs have consultants who help practitioners determine what material to use for a given patient, troubleshoot lens fitting and provide conventional and specialty GP fitting sets.

For spherical GP fits, consider using a topical anesthetic at the fitting. If possible, provide good vision for a new GP patient's first experience with the lenses through empirical fitting (designing the lens via a manufacturer's nomogram or via a topography software program). This option is more viable today with spherical designs because manufacturing quality is more consistent.

When available, fit GP lenses with an ultrathin construction. A recent study (Craig and Foulk 2003) indicates that ultrathin lenses (such as Paragon Thin) resulted in better centration, better initial comfort and increased patient satisfaction vs. GP lenses designed with a standard thickness.

Improving Diagnostic Fitting

If you prefer to use diagnostic lenses to better ensure an optimum lens-to-cornea fitting relationship, you can obtain diag nostic fitting sets in a standard overall diameter (often 9.4mm), with base curve radii from 40.25 diopters to 45.00 diopters and powers of ­3.00D, +3.00D and ­6.00D. Ultrathin and standard center thickness design fitting sets are available in a ­3.00D power. You can order ­3.00D and ­6.00D fitting sets in a low Dk fluorosilicone acrylate material, but you should order the +3.00D fitting set in a high Dk material.

Pat Keech and others have reported that an inventory of at least 200 lenses is preferable to provide same-day dispensing of lenses as well as replacement lenses out of stock. Your inventory could consist of standard diameter lenses with powers ranging from ­1.00D to ­5.00D and base curve radii ranging from 41.50 diopters to 45.00 diopters.

Adding special design fitting sets such as the Polycon SPE Bitoric (CIBA Vision), as well as aspheric multifocal and translating bifocal fitting sets would help you fit highly astigmatic (typically 32.50 diopters of corneal cylinder) and presbyopic patients. If you want to fit special design patients, try fitting a few relatively simple patients initially (such as an early presbyope who wears spherical GPs) to gain confidence.

Brush Up on the Basics

Table 1 provides some of the available resources to assist you in gaining further knowledge and expertise in GP lenses.


TABLE 1 GP Resources


Fitting videotapes, CDs, laminated cards and problem-solving guides

CLMA/RGP Lens Institute 
(800) 344-9060;
GP Fitting CD, orthokeratology manual, yellow filters Polymer Technology Corporation
Fit Today's RGP Modules Paragon Vision Sciences
Series of contact lens modules

International Association of Contact Lens Educators (IACLE)

Gas Permeable Contact Lenses (2nd Edition) Elsevier Publishing
(available December 2003)

Dr. Bennett is an associate professor of optometry at the University of Missouri-St. Louis and is executive director of the RGP Lens Institute.