Creating a happy, successful, progressive addition lens-wearing patient takes a collaborative effort of the optometrist, optician, and lab.
Las Vegas-Creating a happy, successful, progressive addition lens (PAL)-wearing patient takes a collaborative effort of the optometrist, optician, and lab. When PAL patients present with complaints, it's important to follow a systematic, four-step approach to sleuthing the cause of their troubles. That's the word from Pete Hanlin, ABOM, LDO, here at International Vision Expo West.
"Progressive lenses work," said Hanlin, technical marketing manager, Essilor of America. "So when they don't work for a particular patient, the order of the steps you take to address the problem is pretty vital."
Hanlin offered a four-step approach to solving patients' PAL complaints:
No one wants to admit it, but in rare cases, a patient can end up with a pair of glasses that no one has actually checked.
According to Hanlin, in an ideal world every lens would be checked, every time. In some cases, however, lab managers may assume that an optician will be checking the lenses when they arrive at the store, while the optician is assuming that the lab checked the lenses before they were shipped.
"It's a very unusual rare instance, but the point is that we don't live in an ideal world. Mistakes are made, and just because you received the order doesn't mean that it's exactly what you thought it would be," he said. "So it's a logical first step to simply double-check the order to make sure it's accurate."
To err is human, and optometrists do occasionally make refractive errors. According to Hanlin, the most common sources of refraction-based complaints are reducing the minus power in a myopic patient or simultaneously increasing distance and add power in a hyperopic patient. With progressive lenses, both of these courses of action can lead to patient complaints.
"When optometrists increase the plus power of a hyperope, for instance, they also occasionally increase the add power because patients have gotten older and they need a higher add," Hanlin said. "But the combination of increased plus power in the distance and near can dramatically change the reading distance of the lens and generate patient complaints."
"If we fix fitting errors, we could eliminate 80% of the problems patients have with progressive lenses," Hanlin said. "The vast majority of all non-adapts and progressive problems are caused by a poor fit."
According to Hanlin, fitting progressive lenses is fairly easy: simply put the fitting reference point or the fitting cross directly in the center of the patient's pupil. He has heard theories about adding a millimeter or two for myopes and subtracting a millimeter or two for hyperopes, or even moving the fitting reference point up or down based on a patient's height. These theories, he said, are incorrect and ill advised.
Additionally, ensure that your pupilometer is accurately calibrated. "Many people don't know that their pupilometer can go out of adjustment over time," Hanlin said. "If you're using a device that's not accurate, every progressive lens you fit will be wrong because it was based on an incorrect measurement."
In cases where the prescription accuracy, order accuracy, and fit are all correct, problems are almost always due to the frame adjustment, he said.
In many cases, opticians take measurements before adjusting the frame. "When you adjust the frame, it can completely change where the lens is fitting," Hanlin said. "Adjust the frames to the patient's face before taking any measurements, and you'll greatly increase the patient's chance of success."
Unfortunately, this is where most people start, according to Hanlin. "Often when there's a problem with a progressive lens, the first thing I hear from an optometrist or an optician is, 'Let's try a different design.' But if the prescription accuracy, order accuracy, fit, and adjustment are all correct, the lenses should work."
In some cases, however, patients may still have trouble with their progressive lenses even after all the other troubleshooting steps have been followed. These patients might truly benefit from a different PAL design, and it's important that optometrists familiarize themselves with and understand the main attributes of the various lens designs that are available, Hanlin said.
"You want to make sure you're not putting patients into another design that's almost exactly like the one you just took them out of," he said. "If someone is driving a Lincoln Town Car and thinks the car is too big and the ride is too soft for their liking, you wouldn't put them into a Cadillac DeVille. You'd try a different solution. Do a little research to find out what makes various PAL designs tick. Then you can offer your patients options that will make a difference."