Prescribing for Presbyopia
Modify Your Multifocal Prescribing
BY BROOKE MESSER, OD, FAAO, FSLS
While on social media, I saw a post by a practitioner struggling with multifocal success that was followed by dozens of replies. Many echoed the desire for improved success and efficiency in the exam room. Multifocal lenses have improved in recent history, with new brands, materials, and optical profiles. Prescribing tips and tricks have also evolved with these new designs.
The Classic Techniques
Check acuities with loose lenses. Use loose lenses rather than the phoropter to fine-tune distance or near vision. Advise patients to keep both eyes open during power adjustments.
Patient selection and education are still important. While the new multifocal designs have opened doors for more patients, some extra education is necessary to determine whether this modality is appropriate for them.
New Tips for Multifocals
Select trial lenses that will maintain distance vision, then increase the add. Patients may prematurely decide that the lenses will not work if they cannot see well at distance (or near) with the first pair. Be willing to try a second lens to boost near vision rather than having a “one and done” approach. Educate patients that the initial pair should provide comfortable distance vision with an improvement at near compared to their single-vision lenses. Confirm that the distance prescription will not allow any more plus with a brief loose lens over-refraction. Only add minus power if it significantly improves distance acuity, as many patients will notice improved contrast but not necessarily improved acuity with minus power. Then, increase the add in one or both eyes. If needed, further increase the add by adding plus into the sphere in the nondominant eye. The initial fitting may take a few extra minutes, but it will cut down on troubleshooting time at follow ups.
Keep a cell phone handy. Cell phones create different visual demands compared to our near point cards because of colored text, a backlit screen, and pictures. My prescribing experience indicates that the ideal add for a near-point card is rarely the same as the add prescribed for viewing a device. Using a cellphone in place of a near point card may help you reach an endpoint faster. In the same mindset, use loose lenses while looking out a window for refining distance powers.
Know when to stop, for today. A good in-office stopping point is when the distance vision is acceptable for the patients’ demands, and any further plus at near would decrease the distance vision quality. If patients are uncomfortable driving, they are less likely to wear the lenses during the trial period. Reassure patients that, as they use the lenses, their vision will improve and allow for more accurate changes at a follow up. Many patients return to my office noting that they are comfortable with their distance vision and are looking for improved near function. At this point, they are accepting of higher add powers without dramatically changing their distance vision quality.
Astigmats become presbyopic, too! Yes, the optics of toric multifocal contact lenses are complex, but this can be broken down into a simplified process. First, ensure successful vision with a distance toric lens by refining the lens axis and cylinder power. From there, treat the toric multifocal lens as you would a spherical design, modifying only the sphere and add powers. If patients are sensitive to an axis that is not available, consider a custom soft multifocal, which can be made with any sphere or cylinder power, any axis, and customized zone sizes and optical designs. CLS
Dr. Messer practices in Minneapolis in a private optometry office focused on specialty contact lenses. She is a consultant to Precilens and CooperVision, has received research funding from B+L, and has received honoraria from Alden Optical.