Lets face it: If it came down to a popularity contest, PALs (progressive addition lenses) would win first place as the preferred method of vision correction for your patients over the age of 40 when compared with other options such as bifocals, contact lenses or refractive surgery.

When it comes to the ophthalmic lens category, most optometrists will attest that PALs have numerous advantages. PALs offer a smoother transition among distant, intermediate and near vision. And, they offer cosmetic appeal to wearers who dont necessarily want others to know that they are at the age where they need bifocals.

Keeping up with whats new in this explosive category can be challenging, as new technologies seem to enter the market at rapid fire speed. Here is whats new in PALs, whats on deck for the future and some pearls from your colleagues on how to boost your bottom line with progressive lens sales.

 

Whats New

The latest in new PAL designs is freeform manufacturing technology, which results in a product with multiple refractive corrections for a customized lens.

Its almost like a bees eye with millions of little lenses making up the total lens, correcting for higher-order aberrations (HOAs) and unwanted astigmatism, says optometrist Peter Shaw-McMinn, assistant professor of clinical studies at the Southern California College of Optometry and senior partner of Sun City Vision Center, Calif.

Case Report: Custom Readers By Jason R. Miller, O.D., M.B.A.   Patient History A 40-year-old male presented with complaints of blurred vision while reading that was worse in his left eye. He had been experiencing blurred vision for the past year. He did not find over-the-counter readers to be very effective. He was also experiencing headaches and eye fatigue after a short period of reading or computer use. He is an accounts receivable supervisor, and spends about eight hours each day on the computer. His distance vision was unaffected, and he had no other complaints.   Clinical Data His uncorrected visual acuity (VA) was 20/20 O.D. and 20/25- O.S. at six meters. At 40cm, however, it was 20/25 O.D. and 20/40-2 O.S. Manifest refraction was +0.50D O.D. and +2.00D-0.25D:075 O.S. His best corrected VA was 20/20 O.U. Binocular cross-cylinder was +0.75D over MR, and his stereo vision tested at 60 seconds of arc with the Randot test. All other findings were clear and quiet O.U.   Management This patient is demonstrating early presbyopic visual changes. I discussed these changes with him, as well as the benefits of progressive addition lenses. Since this patient was not interested in multifocal spectacles at this stage, I recommended he consider a pair of custom reading glasses. In our office, we have a custom reader kit that comes with a choice of three different frame styles, each available in three colors, and pre-fabricated lenses from +0.75D to +3.00D to fit each frame. I prescribed a pair of custom readers slightly over-plused with a prescription of +0.75D O.D. and +2.00D O.S. This prescription was a good introduction to improved near vision and addressed his chief complaint. This patient not only could realize his improved near vision, but he could even identify the improvement in his near depth perception immediately.   Discussion Pre-fabricated reading glasses can be a difficult market; convenience can be very important to patients. Custom readers may not be a large profit center within your practice, but this service can set your office apart and dramatically increase patient satisfaction. Depending on your patient base, a custom readers center may have a nice niche in your practice. Instead of sending patients out to purchase drug store readers, your practice will be able to provide this service. These patients tend to be extremely pleased with the timeliness and quality of their service, as well as your ability to customize their reading glasses specifically for them.

This new generation of PALs is made using free-form lathes that generate complex surfaces and minimize lens aberrations unlike before, says Brian Chou, O.D., of San Diego, Calif. The idea is to push the envelope on lens customization for clearer, more comfortable vision, he adds.

Heres a snapshot of some of the latest PAL designs and new technologies on the market:

The iZon Progressive lens (Ophthonix) uses a wavefront aberrometer to allow this generation of progressive lenses to attempt to correct HOAs in addition to inherent lens aberrations, Dr. Chou says. The iZon is the only customized PAL driven by a patients unique iPrint (the optical fingerprint) to address the vision problems associated with both lower- and higher-order aberrations of the eye, according to the company.

The Varilux Ipseo is customized according to a patients prescription and measurements of the eye and head movements. Its design provides customized reading areas and peripheral distortion according to how the patient uses his or her eyes. These measurements are taken with Variluxs Vision Print System, a handheld digital device, while the patient looks at a specific object. This produces a head/eye ratio and distinguishes a head mover from an eye mover.

GT2 progressive lenses (ZEISS) have been carefully engineered around the visual and physiological requirements of the wearer using the aberration control of ZEISS Optical Optimization & Management, according to the company. The GT2 lens aims to be virtually distortion-free above the 180 line, and its large near zone is positioned to accommodate eye rotation while reading and general near utility, even when worn in small frames.

Definity lenses, from Essilor, use technology that reduces the effects of astigmatism and allows better focus on the floor by putting the reading power on both the front and back of the lens, Dr. Shaw-McMinn says. This Dual Add technology maximizes the available design space of the lens and provides the least amount of peripheral distortion while providing a smoother transition between all distances. Through Dual Add Technology and digital surfacing, the add power is uniquely split over both the front and back of the lens to optimize optics and minimize distortion.

The Hoya ID (Hoya Vision Care) is an integrated double-surface PAL made with Hoya digital surfacing technology that separates the performance of the front and back surface of the lens and aims to eliminate swimming sensations for wearers.

Carl Zeiss Vision now has an instrument that allows you to choose a lens according to how the frame sits on your face, Dr. Shaw-McMinn says. The Eye-Terminal uses a precision digital camera, a computerized measuring system and a patented laser speckle-target system to measure the patients distance fixation. The Eye-Terminal automatically takes all progressive lens fitting measurements to an accuracy of 0.1mm. It measures pupillary distance, vertex distance and pantoscopic tilt, all of which are important in driving custom progressive lens design, Dr. Chou adds.

The Kodak Unique, by Signet Armorlite, uses proprietary production technology that automatically customizes the lens design for the patients frame selection. This ensures overall visual performance for any B measurement, from a fitting height of 18mm to 13mm, according to the company.

 

What to Keep in Mind

No PAL can offer it all, so lenses should be selected based on a patients needs, whether it is for night driving or working on a computer.

For example, older patients with mobility problems would be best served by the Definity lens; studies have shown that they are less apt to fall because the bottom of the lens is clear at the walking distance, Dr. Shaw-McMinn says. Definity calls this the ground view advantage, he adds. We typically put all our presbyopes in this lens for sunglasses, since they are more apt to be active in sports with them on. It is also a good lens of first choice for converting someone from a bifocal to a progressive, since the unwanted astigmatism is reduced.

Case Report: Progressive Lenses for Cataracts By Peter Shaw-McMinn, O.D.   Patient History A 75-year-old white female presented with the complaint that she cannot see very well to read or drive, particularly at night. She enjoys playing cards and traveling.   Clinical Data She is presently wearing clear bifocal lenses: +2.00D -1.00D x 90 O.U. Her acuity through the lenses is 20/30- O.U. An increase of +0.25D in each eye improved the visual acuity a couple of letters. Biomicroscopy is unremarkable, except for a 2+ nuclear sclerosis O.U. accompanied by a 3+ brunescence of her lenses. Retinal examination is unremarkable.   Management Polarized brown B Definity progressive anti-reflective (AR) sun lenses were prescribed initially. Within a couple of weeks, the patient returned to the practice raving about her excellent vision with her sunglasses. She could not bear to go without them now, and she even wore them indoors at times. Since she had adapted to the progressive sun lenses, clear Physio 360 progressive lenses were prescribed.   Discussion This patient required a higher add so that she could read comfortably. In bifocal lenses, a higher add results in loss of intermediate vision, which she would need for card-playing and traveling. So, a progressive lens is indicated. Ive found that bifocal wearers can adapt to progressive lenses easier when prescribed in sunglasses first; the required vision is less critical, allowing the patient to adapt. The lower part of the Definity lens is focused for the floor, so it may allow for better mobility. Likewise, the lens helps reduce unwanted astigmatism by featuring the add incorporated on both the front and back of the lens. A brown B tint is recommended because the cataract lens is already quite dark, limiting the light to the retina. This tint will block the blue wavelengths and provide more protection. There will also be less scattering of light, since the shorter wavelengths of the visible spectrum will be filtered out, which will provide better contrast. The cataract changes probably have resulted in higher-order aberrations, which will interfere with the patients night vision and cause a poorer quality of image. The Physio 360 lens aims to add no additional coma, as may occur in other progressive designs. The Crizal Aliz with Clear Guard AR treatment (available with the Physio 360) helps block internal reflections, diffuse reflections and specular reflections, allowing more light to enter the eye. A UV coating of the lens will also assist in protecting the eye from unwanted UV radiation and limit scattering of the light, resulting in an enhanced image.

Patients with the beginning stages of eye diseases, such as cataracts, macular changes or corneal changes, will have more HOAs causing glare problems, Dr. Shaw-McMinn adds. These should be corrected with lenses such as the Varilux Ipseo, which reduces the increase in HOAs due to lens design. Ideally, patients with a high level of HOAs would see best through iZon Progressive lenses, which correct them all, he notes.

While the new freeform PALs certainly are popular, of course, they may not be right for everyone. Although a lot of attention these days is directed to the new freeform digitally surfaced progressive lenses, Im somewhat surprised by how many practitioners overlook the near variable focus lenses for their presbyopes, Dr. Chou says.

Some of these near variable focus lenses include the Zeiss RD, Zeiss Business, Sola Access, Hoya Tact and Shamir Desktop. These progressive lenses have the real-estate of the lens area optimized for seeing at a desk (for computer reading range), Dr. Chou says.
Since there is no distance zone in these glasses, the viewing areas for computer and near are substantially larger to eliminate awkward viewing positioning. These are superb lenses for patients that spend a significant amount of work at a desk or computer.

 

Good, Better and Best

When it comes to vision correction choices for presbyopes, ophthalmic lens options are growing at the most explosive rate, according to Birmingham, Ala., optometrist Jack Schaeffer, past chair of the American Optometric Association Contact Lens and Cornea Section.

With so many choices, Dr. Schaeffer recommends that practices offer a full range of options from the most basic to the top premium PAL for their patients.

If you are going to be the best practice, you need to utilize the best products, Dr. Schaeffer says.

If you consider that an estimated 90 million people in the United States either currently have presbyopia or will develop it by 2014, PALs can provide a significant income boost for a practice. So, how can O.D.s boost their bottom line with PALs?

Dr. Schaeffer offers these helpful tips:

Keep yourself educated and up-to-the minute on new PAL designs.

Communicate the benefits of the various PAL designs to your patients. Tell them We have good, better and best, and explain the benefits of each, he says.

The majority of patients will spend extra for a high-level freeform lens, Dr. Schaeffer added.

Considering that most presbyopes need to change their prescription every 1.5 to two years, spending extra for a freeform lens with no distortion is worth the cost to most patients. Most patients will opt for this lens if you explain it to them properly, Dr. Schaeffer notes.

Constantly train your staff to keep up with the new technology. Typically, Dr. Schaeffer holds regular meetings to discuss new PAL options with his staff.

In addition, if a new product comes out on the market, he holds two sessions: one with managers, and one with the sales staff. In each, they discuss an overview of the lens, its benefits and the fee associated with this new product.

 

The Next Frontier

So, whats the future for PALs? Expect the changes to keep on coming. Dr. Shaw-McMinn cites the latest edition of Borishs Clinical Refraction, which predicts that incorporation of wavefront technology will become part of everyones everyday practice, and that as the technology improves, we will witness new lenses that approach optical perfection.

Think about the Hubble Telescope and the fantastic images it has been sending back. That is because of the correction of HOAs, Dr. Shaw-McMinn says.

What that could ideally mean when it comes to lenses: A design that combines the correction of a patients particular HOA, near vision segment size and peripheral soft designs specific to the viewing habits of the patient, as well as negation of the unwanted astigmatism on both sides of the lens and a high index material with a low Abbe value.

This [hypothetical] lens would combine the benefits of several lenses now on the market, Dr. Shaw-McMinn says. It may take a while, but we will eventually get there.