Once you have determined that a patient is a potential candidate for translating multifocal contact lenses, the manner in which you present this option will determine whether the patient will decide to exercise it. Your introduction of these lenses plays a big role in patients’ ultimate success as wearers of translating multifocal gas-permeable (GP) lenses.
So, it’s a good idea to begin planting the seed well before the need arises. Mention to your GP wearers—in their late 30s or early 40s—that the time will eventually come when they will need help seeing at near. After they settle from the initial shock, let them know that many options are available to them, including multifocal contact lenses. Most GP wearers do not want to give up wearing lenses just because they need multifocals. By starting this discussion well in advance, you are helping patients to be prepared. They will not be surprised that you have a plan, and more importantly, they will not need to give up their lenses.
Set Realistic Expectations
When the time comes to implement multifocals into the treatment plan, be positive and candid. Explain that this new correction may not satisfy all of their visual needs. They can realistically expect GP multifocals to satisfy 75% to 80% of their needs. Supplemental spectacle correction for specific needs is not unusual. Patients will be much more amenable to this if they are aware of this need in advance of the fitting process. When both the practitioner and the patient are committed to the process and have realistic expectations, the rate of success should be similar to that of fitting GP toric lenses. But, in some cases, even with the best preparation possible and extremely motivated doctors and patients, the first lens fit may not be the only lens fit. Unforeseen problems do arise and must be dealt with in a timely manner. Here are some common problems and their most likely solutions:
Poor Distance Acuity
• Over-refract and adjust the lens power if necessary.
• If the near segment is too far into the papillary area, truncate the lens to lower the segment height.
Poor Near Acuity
• If there is poor lens translation, flatten the base curve to aid translation.
• If the near segment is too low, order a new lens with a higher placement of the near segment.
• If the power is insufficient, order a new lens with more add. Insufficient near add could also present if the distance zone is under-plussed.
Flare at Night
• If near segment is too high, truncate the lens to lower the seg.
• If the optic zone diameter (OZD) is too small, order a new lens with a larger OZD. Note that a larger OZD will create more sagittal depth over the optic zone and it will probably be necessary to flatten the base curve to maintain similar lens-to-cornea fitting relationships.
Try any one or a combination of the following:
• Steepen base curve.
• Increase the OZD.
• Increase prism.
The Lens Rotates But is Stable
When the lens consistently rotates and orients itself in the same manner:
• Increase prism.
• Compensate for the rotation when ordering a new lens.
The Lens Slides Under the Lower Lid
• If translation is poor, flatten the base curve and/or decrease the OZD.
• Increase prism.
• Truncate the lens, which may cause the near segment to be too low to be useful. (Caveat: Truncating a prism-ballasted minus lens actually reduces prism effect, if prism and truncation are employed. The opposite is true for a prism-ballasted plus lens.)
Know When to Ask for Help
Fitting problems with translating multifocals may extend beyond the issues mentioned here. But, hopefully this column will provide you with a good starting point. Should you experience a problem and require additional help resolving it, one of the best sources of help are the lab consultants. Just a few minutes on the phone with a lab consultant will give you insight into a possible solution for your patient.