When many of today’s experienced eye care professionals first learned to fit soft multifocal lenses, there were complicated fitting protocols, and numerous lens power tweaks and countless follow-up visits were needed. Thanks to new manufacturing technologies and designs, most new-generation soft multifocal lenses require only a spherical equivalent and an add power to start.
To ensure maximum success in fitting these lenses, Dr. Roxanna Potter, Dr. Shalu Pal, and Dr. Mary Jo Stiegemeier—instructors in the Soft Toric and Presbyopic Lens Education (STAPLE) programme for optometry students—have developed a few guiding principles:1
Choose appropriate patients
Potential wearers most likely to be successfully fitted with soft multifocal contact lenses are:
- Candidates with previous experience of wearing contact lenses
- Highly motivated candidates, such as early presbyopes, multitaskers, patients frustrated with progressive spectacles or reading glasses
- Moderate-to-high myopes and hyperopes versus emmetropes
Once you feel ready to try multifocal toric lenses, you can begin fitting patients with astigmatism >1.00D.
In general, the higher the add power, the more difficult it is for patients to adapt to contact lenses. Naturally, the same is true for fitting progressive spectacle lenses.
Manage patient expectations
Before prescribing a patient’s first soft multifocal lenses, it’s important to have a discussion about the fitting process. Be sure to explain that:
- It typically requires 2 or 3 visits to successfully fit these lenses; this is to ensure that the patient gets the best possible vision correction
- Patients normally take several weeks to adapt to their new lenses—patients need to have patience!
- A goal for these lenses is to provide adequate vision for 80% of a patient’s daily tasks (this is conservative, but underpromised performance leads to stronger perception of success)
- Some wearers do not have their visual needs entirely met by contact lenses alone—they may occasionally require reading glasses
Make sure that every patient understands your fitting fees and your policies on refunds and cancellations before the process begins.
Optimise your refraction
An accurate refraction is the foundation of the fit. Push the highest plus acceptable for distance, and the least plus for near, to avoid excess accommodation with an over-minused refraction.
When selecting soft multifocal lenses to fit a patient, first calculate their spherical equivalent. Place this prescription in a trial frame, pushing as much plus as possible.
Determine eye dominance
Testing sensory dominance rather than sighting dominance is the most effective way to achieve successful fitting of soft multifocal lenses. Use a handheld +1.50D or +2.00D lens, alternately placed over each eye (while best corrected) to determine which position creates less blur with both eyes open. This can help determine whether more plus or higher add powers should be used in the non-dominant eye to improve near vision without compromising distance vision.
Test against real-world conditions
In appropriate lighting, test the patient’s vision using a mobile phone or magazine rather than an eye chart. Check only OU acuities at distance and near after allowing patients a few minutes to adapt. Let patients know that some shadowing or mild blur may be apparent for a few weeks.
Accept occasional need for ‘Plan B’
Some patients are simply unable, or unwilling, to put in the necessary time to adapt to multifocal contact lenses. After asking patients about their experience and determining that they will not be successful with soft multifocal lenses, discuss possible alternatives. Provide reassurance that technology is continuing to advance and that you will keep them updated about new possibilities as they arise.
Knowing that you are looking out for their needs will reassure your patients and help maintain their loyalty.
1. Potter R, Pal S, Stiegemeier MJ. Avoiding the soft multifocal failure. Contact Lens Spectrum. 2016;31:22-25.