contact lens primer
The End Is Near
BY TIMOTHY B. EDRINGTON, OD, MS, FAAO, & JOSEPH T. BARR, OD, MS, FAAO
This column is a summary of past "Contact Lens Primer" pearls that we have gleaned from the archives. We will present them in the last two columns.
Back to the Basics
"My rigid lens hurts." If the discomfort is immediate and does not abate with time, re-contour the edge. To confirm that the edge is the culprit, pull the patient's eyelids away from the lens edge. If a sigh of relief ensues, the edge needs attention. Even if the patient does not complain of discomfort, he'll appreciate a quick polishing of the lens front surface and a re-contouring of the edge.
Don't Always Keep It Simple
Even though a spherical GP lens may provide your patient with good vision and comfort, consider a bitoric design when there is 2.00D or more of corneal toricity. The bitoric design will minimize corneal molding and lens-induced distortion, thereby minimizing spectacle blur.
If a bitoric GP lens is indicated, use a bitoric as your first diagnostic lens. If you do not have a bitoric trial lens set, order empirically using the Mandell-Moore guide (available at www.rgpli.org). Then fine-tune the fit after assessing the fluorescein pattern of the bitoric lens. If the fit is too flat, steepen both base curve meridians. You know what to do if the fit is too steep. Over-refract to fine-tune the final lens powers.
Teach Your Patients Well
Patients should learn about their eyecare and eyewear options in your office. You best understand the patient's refractive error, ocular and systemic history and vision needs.
When prescribing soft toric lenses, describe to patients how they work and that occasional axis misalignment with resulting temporary blur in vision is to be expected. Create realistic expectations: inform patients that overall they will be pleased with their vision and that it will be "comparable" to the vision they obtain through their new spectacles. Reinforce expectations at each visit.
If you do not have a soft toric lens close to the patient's prescription in stock, empirically ordering the initial trial lenses will save chair time and enhance the patient's first experience.
Lens care products are improved regularly. To keep current, read published research and information from manufacturers.
|Figure 1. Spherical GP lens on a with-the-rule cornea.||Figure 2. Toric GP lens on a with-the-rule cornea.|
Ask patients to demonstrate their proficiency in lens application, removal and care system use prior to dispensing lenses and at the initial follow-up visit. Also, don't assume current or past contact lens wearers are proficient or compliant. If patients understand why following instructions is important, they tend to be more compliant. Signs and symptoms of eye and contact lens problems and the appropriate patient action should be explained at every visit.
Show Patients the Dessert Tray
Present part-time contact lens wear to your non-contact lens-wearing patients. Daily disposables are ideal for social events and for weekend athletes. This option, once offered, might evolve into more than occasional wear.
Dr. Edrington is a professor and in the contact lens service at the Southern California College of Optometry. E-mail him at firstname.lastname@example.org.
Dr. Barr is editor of Contact Lens Spectrum and assistant dean for clinical affairs at The Ohio State University College of Optometry.