Prescribing for Presbyopia
Fitting Approaches for Soft Multifocal Success
If you haven't recently prescribed soft multifocal contact lenses, now might be the time to give them another chance. Designs, materials and lens reproducibility have all improved.
Find Your Starting Point
We recommend that you talk with your eyecare colleagues to narrow the extensive field of multifocal lens choices down to a few to start with. Then use the manufacturers' fitting guides and consultation services to assist you with your initial fitting experiences. As you gain experience with each design, you'll develop your own prescribing strategies and fitting pearls.
For soft multifocal lens options, select initial diagnostic lenses according to manufacturers' recommendations. Abandon your phoropter and use loose spectacle trial lenses to fine-tune the lens powers. One of the most important steps in prescribing multifocals is to really understand what's important to each patient from a vision standpoint. Determine each patient's visual needs, especially with regard to near and intermediate distances. A comprehensive discussion regarding their work and leisure visual demands may help to develop visual priorities.
To test intermediate needs, we commonly sit soft multifocal patients in front of a computer screen. For final contact lens power determination, we seldom need to change the power by more than 0.25D or 0.50D from the manufacturers' guidelines. If a patient achieves acceptable vision through the trial lenses, then dispense the lenses and reschedule the patient to return in approximately one week for follow-up care. If you, the patient and the patient's corneas are pleased with the performance of the lenses, then prescribe. You aren't searching for visual perfection, but visual happiness for the patient.
Obviously the above scenario doesn't occur with every multifocal fitting. Patients may report that their vision is pretty good, but could be better at either distance or near/intermediate. For instance, a patient might be satisfied with his near but not with his driving vision. Consider in this case prescribing a single-vision lens with the patient's distance correction on the dominant eye.
Another option is to prescribe a different multifocal design or a multifocal lens from a different manufacturer that optimizes distance viewing. An example would be an aspheric or annular design with a larger distance optic zone located in the lens center.
Several options are also available for patients who are pleased with their distance vision, but aren't completely satisfied with near vision through multifocal lenses. If the near vision is acceptable for most tasks, consider prescribing reading glasses for part-time wear when needed.
Another option is to prescribe additional plus at distance and/or near for the non-dominant eye. This may slightly blur the distance vision in this eye, but will generally improve intermediate and near vision. A single-vision lens for near is also an option.
The Bottom Line
Patients are interested in new technology and new products. Even if you don't prescribe multifocal contact lenses, the patient was able to try something new. Patients will also view you as an eyecare practitioner who embraces change and who is constantly exploring ways to improve their visual welfare. Remember that there's no one right answer when considering multifocal contact lenses for patients. Good listening skills and creativity are the keys to successfully prescribing multifocal contact lenses.
Dr. Edrington is a professor at the Southern California College of Optometry. E-mail him at email@example.com. Dr. Schornack is the associate dean of Clinical Education and serves in the Cornea and Contact Lens Service at the Southern California College of Optometry.