How to better fit progressive spectacle lenses

September 14, 2017

Article

Better understanding progressive spectacle lenses (PALs) and how to troubleshoot the fit leads to happier patients who are satisfied with their vision.

Las Vegas-Better understanding progressive spectacle lenses (PALs) and how to troubleshoot the fit leads to happier patients who are satisfied with their vision.

Valerie A. Manso, ABOC, FNAO, says that optometrists and opticians should forget about “one size fits all” with PALs. Manso is president of Manso Management Resources, a training and development company specializing in the ophthalmic industry.

“Through adapting the lenses, whether design or refraction, we can make life better,” she says.

In an ideal world, patients put on their new eyewear and things are perfect.

However, some patients will immediately reject the eyewear, while others will return after a period of time of struggling with the eyewear.

“How we handle patient complaints, troubleshoot the offending eyewear, and subsequently resolve the problems are important skills,” says Manso.

Patients are beginning to wear multifocals earlier in their lives.

“Multifocal use is starting now when people are in their late 20s and 30s,” Manso says. This is change; in the past, multifocal use began in the late 40s and 50s. This is due to computer and device use. We are focusing on that distance is not natural.”

In today’s world of digital reviews, ODs and opticians want patients to be talking about them in the right way.

“We want them talking about our phenomenal service,” says Manso. “We are competing with outlets with no brick and mortar store. We want everyone to turn into raving fans. Yes, we do charge more because we do it well and we resolve complaints.”

When patients present with problems look to evaluate the prescription (distance, mid-range, near) as well as the fit of the lens and frame.

Evaluating the fit includes pupil height, pupillary distance, pantoscopic tilt, vertex, and facial wrap.

PAL market and patient acceptance

PALs are now a dominant mode of correction for presbyopia, comprising 75 percent of multifocal dollars in the United States. However, Manso reminded attendees that more flat-top bifocals are sold than PALs.

PALs are the preferred modality for most presbyopes, according to Manso, especially for bifocal wearers. Patients prefer vision through progressives as compared to other presbyopic lens corrections.

Fitting patients with PALs as emerging presbyopes is important:

• Lower add designs have fewer aberrations

• Patients adapt easier

• This is thought to be the easiest fit

However, Manso cautions that emerging presbyopes includes a large number of people who have never worn eyeglasses. They are very sensitive to blur and are not used to variable power.

Says Manso: “The goal is to get folks into progressive lenses as soon as possible. We’re starting to do that with millennials to help with near power.”

For existing PAL wearers, ODs and opticians are reluctant to switch brands because they fear nonadaptation.

“People with experience wearing progressives often notice differences in ‘feel’ of designs or notice vision is better,” says Manso.

Practitioners shouldn’t fear changing the design, she says.

“Just because it works doesn’t mean we shouldn’t change it,” she says.

Frame selection and fitting

Remember that choice of frame for PALs makes a difference. Fashion plays a role; frames that are narrow and shallow lead to short-corridor PALs.

Says Manso: “Whenever we can take an eye and give it at least 20 mm in seg height, we’re doing the right thing.”

Frame choice and fit can affect how the lenses work.

Remember these tips for frame selection:

• Ensure the frame allows for the minimum fitting height of the selected progressive.

• Ensure the frame allows for a minimum of 10 mm at distance.

• For most general-purpose PALs, minimum depth of 22 to 28 mm is recommended.

In frame fitting:

• Before taking any measurements, make sure the frame is adjusted to how the patient will wear it.

• Minimize the vertex distance to ensure a wide field of vision at all ranges.

Digital lenses

ODs and opticians need to be proactive in selecting high-end lens designs for patients.

“In the digital age of high-definition TVs and phones, lens technology has caught up,” she says. “Digital lenses are the most important improvement in Rx eyewear in the past 100 years.”

Digital lens technology allows for optimization of each individual lens power. This will virtually eliminate power error and result in superior clarity, performance, and patient satisfaction, according to Manso.

Adding measurements such as pantoscopic tilt, vertex, and frame wrap will customize that eyewear to the patient.

“If we take those measurements, we end up with a better result in the lens with digital processing,” Manso says. “That is called a compensated Rx.”

If no measurements are submitted with a lens order, default specs are:

• Frame wrap: 5 degrees

• Pantoscopic tilt: 9 degrees

• Vertex: 13 mm

In recommending digital lenses to patients, remember to:

• Walk your talk: wear digital lenses yourself.

• Keep the message simple: Digital lenses are the latest and best in optical technology. Use the analogy with high-definition TVs and smartphones.

Manso recommends lens enhancements to customize every pair of eyeglasses.

“Just with the use of enhancements I can improve visual outcomes depending on the use of the lenses,” she says.

Enhancements include:

• AR treatment

• Photochromic

• Polarized

• Blue light protection

• Tint

• Mirror coating

Troubleshooting PALs

Troubleshooting PALs starts by understanding how the patient uses the lenses, according to Manso. Ask the patient if anything has changed.

“By understanding if anything has changed, overall lifestyle changes, and listening to the patient, you can come up with solutions,” she says.

Review existing eyewear:

• Pantoscopic tilt

• Face form

• Vertex distance

• Multifocal placement

Establish realistic expectations for patients. Detail the differences in the new eyewear (lens design, material, add-ons, performance), demonstrate the differences. Be sure to review and reiterate at time of glasses delivery.

“I don’t put the glasses on the patient at delivery until I have established realistic expectations,” says Manso.

Take the time at delivery to show your patient how use the eyewear.

Talk about adaptation time; remind patients that different is not bad.