SOFT MULTIFOCAL FITTING
Avoiding the Soft Multifocal Failure
Forget what you know about soft multifocals; newer designs and brushing up on the basics make it easy to succeed.
By Roxanna Potter, OD; Shalu Pal, OD; & Mary Jo Stiegemeier, OD
With new technology and improved lens performance, it’s easier than ever to believe that soft contact lens fitting is simple. This can actually be problematic, not only because of resultant patient perceptions, but also because of ensuing practitioner fitting habits. What is often forgotten is how much practitioners must learn to effectively fit soft contact lenses.
A good way for practitioners to remind themselves of the education and training that is required to fit soft lenses is to work with optometry students. Their attention to detail, naivety of industry politics, and lack of brand partialities that can come with experience is quite refreshing. Returning to basics (and often back to forgotten techniques that are beyond basic) can bring a renewed clinical perspective for even the most seasoned practitioner.
The Soft Toric and Presbyopic Lens Education (STAPLE) Program is an especially beneficial program that provides hands-on soft toric and multifocal lens fitting workshops to optometry students in the United States and Canada. In these workshops, students are given an overview lecture and then have an opportunity to fit lenses from four different contact lens companies on patients recruited specifically for the event. This program is a collaborative effort sponsored by Alcon, Bausch + Lomb, CooperVision, and Johnson & Johnson Vision Care.
The goal of these multi-company workshops is to provide students with an unbiased education and to inspire confidence in fitting both the soft toric and multifocal lens categories. Students have an opportunity to experience fitting success with a variety of presbyopic and toric lens options. As instructors for these workshops, we have found numerous take-home points to be worth incorporating into our own fitting strategies. We feel that our fellow contact lens fitters would also do well to remember them, particularly when it comes to achieving success with soft multifocal lenses.
Appropriate Candidate Selection
When beginning to fit soft multifocal contact lenses, targeting certain candidates can result in greater success. The best candidates include early presbyopes, multitaskers, active people, and those frustrated with progressive spectacles and readers. Previous contact lens experience is also beneficial, although not required. Moderate-to-high myopes and hyperopes are easier to fit compared to emmetropes, and it’s recommended to initially avoid patients who have astigmatism greater than 1.00D.
Once comfortable with a few easier fits, practitioners can begin to present multifocal contact lenses to all appropriate presbyopic patients. The key is to take a moment to present the option to all potential candidates, while being mindful of custom lens options that may be required for patients who have higher amounts of astigmatism or other specific concerns.
Fitting early presbyopes with multifocal lenses can prevent many future accommodative loss and non-adapt issues. In addition, avoiding monovision limitations such as poor contrast, depth perception, and intermediate vision is beneficial. Switching a monovision patient to multifocals can be much more difficult compared to starting with multifocals initially, as is waiting to fit patients with multifocal contact lenses until they require a high add. Most new-generation multifocal lenses have an aspheric simultaneous vision design. The higher the add power that patients require, the more difficult it is for them to adapt to the design. This is the same principle as fitting progressive spectacle lenses.
Set the Right Expectations
Before choosing initial lenses, it’s crucial to have a conversation with patients about the process of fitting these lenses. It typically takes two to three visits on average to successfully fit multifocal contact lenses. Additionally, several weeks are needed for accurate adaptation to these lenses and to properly determine visual potential. Advise patients that a conservative goal for these lenses is to provide adequate vision for 80% of tasks performed. When performance is under-promised and over-delivered, patients will perceive success to be achieved.
Patients who have critical visual demands at work or home may not be able to have their visual needs met with contact lenses alone; advise these patients that readers may be necessary to periodically enhance their near vision. It is important to have a backup plan and to tell patients what to expect. Knowing that there is a backup plan in case they are not successful is reassuring to patients.
Lastly, inform patients of fitting fees and any refund or cancellation policies before beginning. A mutually agreed upon plan with reasonable expectations is the best type of plan.
Perform a Careful Refraction
It is important to initiate the soft multifocal lens fitting process with the most precise refraction possible. This is the foundation of the fit, so it is critical to perform a comprehensive and accurate job. Push the highest amount of plus acceptable in the distance and the least amount of plus at near. The goal is to avoid excessive accommodation with an over-minused refraction and to minimize adaptation issues resulting from too high of an add power.
When selecting your initial multifocal contact lenses to fit a patient, it is necessary to calculate the spherical equivalent. Test this prescription before applying trial lenses by placing the refraction in a trial frame and pushing as much plus as possible. Do not use a phoropter to test this “most plus” spherical refraction. Attempting different multifocal powers when the base refraction is inaccurate will limit success and waste both the practitioner’s and the patient’s time.
Determine Eye Dominance
Many fitting guides recommend using eye dominance to help determine the initial lens selection and to identify appropriate lens changes to correct distance and near vision issues. There are two ways to determine eye dominance: the sight dominance and the sensory dominance methods.
Sight dominance is determined by extending the arms and making a triangle shape with the thumbs and forefingers, then viewing a distant object through the triangle; patients close one eye and then the other, and whichever eye they are using to view the distant target is considered the dominant eye.
Sensory dominance is determined by testing sensitivity to blur using a +1.50D or +2.00D lens. Sensory dominance leads to better success when fitting soft multifocals. It can be accomplished using a handheld trial lens alternatingly placed over each eye (while best corrected) to determine which position creates less overall visual distortion with both eyes open. For example, if a patient reports better vision with the right eye blurred (as opposed to when the left eye is blurred), then the left eye is considered dominant. This determination allows more plus or higher add powers to be used in the nondominant eye if needed to improve near vision without compromising distance vision.
Alternatively, a version of this test can be performed in the phoropter using the “R” or retinoscopy lens over each ocular. This is somewhat less desirable compared to a free-space trial lens as it is not a real-world type environment, but it can be performed very quickly at the conclusion of the subjective refraction.
Follow the Fitting Guide
When selecting lenses, it helps to forget everything you knew about fitting previous multifocal lens designs and allow yourself to be taught the correct way to fit the new generation of multifocal designs. The processes involved in fitting these lenses are much simpler than you might think. It involves much less work, and it is how optometry students have been taught for the last 10 years. Multifocal contact lens fitting has been simplified by fitting guides that were developed and refined through industry-sponsored research and development.
We need to resist the urge to return to our old ways of trying every possible power combination that intuitively makes sense; instead, we simply need to trust the fitting guides. This applies to both initial lens selection and to troubleshooting techniques. Previously, complicated formulas or refraction tweaks were used to determine initial lenses. Now, most designs only require a spherical equivalent refraction and an add power to start.
Test Under Real-World Conditions
Once lenses are on, test patients’ vision using real-world conditions. This includes appropriate office lighting, using a magazine or cell phone rather than a chart to assess near visual function, and checking only OU visual acuities at both distance and near. It is strongly recommended to allow patients a few minutes to adapt prior to checking acuities, and expect some blur initially in-office. If acuities are reasonable (generally around 20/25 OU or better distance and near), dispense the lenses and allow patients time outside of the office to adapt before making any changes. Reassure patients that they may see shadowing or mild blur for a few weeks and that it is normal for neural and perceptual adaptation to take some time.
A phone call follow up is reasonable after one week, and many complaints can be easily resolved by an encouraging staff member who can reassure patients that adaptation takes time. In-office follow up is unnecessary until two to three weeks after dispensing, as fewer changes will be necessary with better, longer adaptation.
When troubleshooting, follow the fitting guide. It’s difficult to let go of the idea of a structured over-refraction to find the best combination of powers, but simply adhering to the guidelines shortens the fitting process and improves success rates. If the recommended fitting guide techniques aren’t effective, consider rechecking base refraction and obtaining monocular acuities to determine whether any simple refractive changes are needed. Assess the distance vision first, even if the complaint involves near vision, and recheck eye dominance if needed. For near complaints, try performing a binocular distance over-refraction to determine whether any more plus can be added to the distance prescription before increasing the add. Make sure to ask patients what specific tasks are difficult for them to perform, and use this information to adjust parameters appropriately.
Also, it is critical to not forget common barriers to contact lens success in general. These may include ocular surface disease, dry eye, allergies, deposits, and solution sensitivities. It’s best to treat these conditions before any contact lens fit is attempted, as they can severely limit success with soft multifocal lenses. In subtle cases, these conditions can often be overlooked until problems arise with contact lens wear.
Lastly, don’t forget that application and removal difficulties may cause problems unique to presbyopes. For example, presbyopic hyperopes often have great difficulty clearly seeing the lenses with their uncorrected vision during the application and removal process. Swapped, lost, or torn lenses may cause problems without patients knowing or reporting this as a contributing factor to their complaints.
Know When to Quit
Although difficult, it is important to know when to give up on a multifocal fit. Some patients are simply unable to adapt to multifocal designs, or they are unwilling to put in the time necessary to fully adapt. An honest conversation about expectations and level of commitment to the fit is occasionally necessary to determine whether further troubleshooting attempts are worthwhile. As a rule, adjustments should be limited; it helps to specify a number of allowed attempts in the initial fitting discussion, as some patients will keep requesting different trial lenses or adjustments in the hopes that a “perfect” lens combination will be found. Appropriate expectations of multifocal lens performance will help prevent both practitioners and patients from wasting time on this ultimately futile exercise.
If a patient is sincerely trying to adapt and has reasonable expectations, and there are no obvious refractive, fit, or ocular health issues limiting the fit after a few adjustments, then it is prudent to explore some of the more rare limitations to success. Topography performed over the lenses may show subtle decentration or flexure issues. Borderline amounts of astigmatism may need to be addressed, or, in other cases, more aggressive dry eye therapy may be required. It is also not unusual for some patients to require months of adaptation rather than days or weeks.
Ultimately, if it appears that a patient is not going to be successful with soft multifocals, be prepared to discuss alternative options. This may include modified monovision with soft multifocal lenses, GP or hybrid contact lens designs, monovision, or progressive spectacles. To retain patient loyalty, even after much time and money have been spent but failure has resulted, it is important to make sure that patients have an acceptable solution for their visual needs and that you assure them that you will keep them updated as new technology is developed. If they know that you haven’t given up permanently, they will often be satisfied to wait for future lens designs to try in years to come.
Do not feel the need to refund any fitting fees that may have been charged, as the time invested in working with these patients is often significant. Payment should not be determined by whether or not the fit was successful, but by the expertise and time required of the practitioner and staff involved.
Multifocal lens fitting was once reserved for specialty lens fitters, but much has changed. Optometry students are taught to fit these lenses because they are now considered a part of primary eye care. New designs allow for higher rates of success, and with more options in material, parameters, and modalities, nearly any presbyope can be considered a candidate. The best advice that we can give is to jump in and give multifocal fitting a try, using the basic tips outlined here.
Remember to allow for adequate adaptation time, and follow the fitting guides, as they are proven to lead to success. Just like the students in the STAPLE workshops discover, if the basic techniques of contact lens fitting are utilized, patient satisfaction is nearly always achieved, and practitioner confidence will increase dramatically with each fit performed. CLS
Dr. Potter owns a private practice in Sylvania, OH. She has received travel funding or reimbursement from the STAPLE Program and lecture or authorship honoraria from the STAPLE Program and the GP Lens Institute. She can be reached at firstname.lastname@example.org.
Dr. Pal runs a specialty lens and dry eye practice in Toronto. She is a member of the AOA Contact Lens and Cornea Section Council and a member of the Women’s Advisory Board for Alcon USA. Dr. Pal is a consultant for Allergan, Alcon, B+L, Candorvision, Coopervision, and Johnson & Johnson Vision Care and is a facilitator of STAPLE program workshops.
Dr. Stiegemeier is in private practice in Ohio specializing in therapeutic contact lens fitting. She also is staff optometrist at the Cole Eye Institute, Cleveland Clinic Foundation, Specialty Contact Lens Clinic, Department of Ophthalmology. In addition, Dr. Stiegemeier is an adjunct assistant clinical professor at Pacific University College of Optometry and an adjunct assistant professor at University of Missouri - St. Louis.