HIGH-INDEX Tales & Techniques

With millions of people in the U.S. requiriing high single-digit and double-diigit corrections for myopia and hyperopia,, having core skills in frame selection and fitting,, as well as lens logic pertaining to this group, is crucial to maintaining a profitable business

BY KARLEN MCLEAN,, ABOC, NCLC
Photography By Peter Baker

High-correction patients come with built-in predispositions and assumptions about eyewear, especially the thickness and weight. They may likely be aware of thinner, lighter lens options, but aren't sure how those options apply to their Rx and frame choices.

Sometimes it may mean bursting their bubble (“What do you mean my lenses will be thicker in this rimless style?”) and resetting their parameters. But once you establish a working-together relationship and spend some time helping these patients, your professionalism will shine through.

HIGH-PLUS

High-plus patients have lenses that are thicker in the center and thinner at the edges, and their lenses tend to magnify their eyes' appearance. Kids' prescriptions are often high-plus, and special attention must be paid to frame selection for proper frame fit and to keep the patient's view through their lenses centered and clear.

“Selecting a frame with an A measurement, plus half the bridge slightly wider than the child's PD, is recommended to help balance proper fit with projected growth,” says Chelsy Pham, ABOC, analyst, quality, systems and logistics, VSP Optics Group. “However, getting frames that are too wide can cause issues with the appearance of lens thickness in high myopes or problems with proper centration in hyperopes.”

So, what frame characteristics should you look for? “Frames should fit comfortably without sliding off the face and with the pupils in the center of the lens to minimize decentration,” Pham advises. “It's important to note that as the eye size of a frame increases, the higher the plus power, the thinner the lens edge will be. For high-plus powers, it helps to use an aspheric design to flatten the lens.”

Additionally, steer clear of grooved rimless frames for high-plus Rx's, since high-plus powers thin lens edges, and labs need to compensate for edge thinness by making thicker lenses for secure mounting into the frame. “We see plenty of children with first-time Rx's that are high plus,” observes Matthew Watson, OD, owner of Eyevolution Optique in Nyack, N.Y. “We start out with education before we look at frames, so parents know what to expect.”

The practice fit a two-year-old with a +8.50D in his first pair of glasses. “We worked with parents and the child, doing up-close tasks until he became accustomed to wearing his glasses,” Watson says. “He was sent home with stickers, a coloring book, and a puzzle; all things he could sit and enjoy doing while he was adjusting to life with glasses. We just filled his third Rx, now with photochromic lenses. We have a solid relationship with the family, and we get to watch this patient grow!”

HIGH MINUS

High-minus patients' lenses are thicker at the edges, and eyes often appear minimized. High-minus lenses can be thick, unattractive, and uncomfortable, but utilizing the latest lens technology helps with “high-minus hate.”

Some high-minus patients are also contact lens wearers, but long hours at computer screens and presbyopia may result in longer-term eyeglass wear.

Resistance to wearing glasses and progressives can make for a challenging high-minus patient to please.

“We had a −9.50D patient who had been wearing PALs in a drilled rimless, and she disliked the thickness of her lenses, plus said that her PAL vision wasn't sharp,” relates Brandi Kay, manager of the Glastonbury, Conn., location of Harvey & Lewis Opticians. “Her drilled rimless showcased lens thickness, and her 1.67 PAL was a great lens, but could be improved.”

The solution was to minimize thickness and maximize viewing room. “We fit the patient in a full-metal frame—she felt plastic frames were too bold for her—and an even thinner 1.74 lens option,” Kay says. “Digital surfacing produced a PAL with large, wide zones. She was thrilled with the new lens thinness and visual acuity.”

The practice also fit the patient with single vision sunwear, updating small metal frames—which didn't offer much protection—to a somewhat larger option with 1.67 material and gray polarized lenses.

Virginia Burton, optician-owner of Burton Optician in Washington, D.C., specializes in small frame sizes and carries several round frame styles, ideal for high-minus prescriptions, since eliminating edges helps cut down on edge thickness.

“I recently fit a −12.75D patient in a round plastic 41-19 eyesize and 1.70 PALs,” she says. “Months later, I fit a −14.50D who looked great in a semi-rimless top-rim, round metal frame in a 39-21 eyesize in 1.70 material. Both were first-time PAL wearers and both were happy with their vision and new look.”

TROUBLESHOOTING

Sometimes, it's about realistic frame choices for high-Rx patients.

“We discuss where lenses will be thickest, what materials we'll use depending on frame choice, and the costs of each choice,” says Danielle Watson, the office manager of Eyevolution Optique. “If a high-minus patient wants to wear big hipster-retro or rimless frames, I take out a stock poly lens and calipers and show them how thick their lenses will be.”

“The highest minus we've fit so far is a −16.50D with a −1.50 cylinder,” Watson continues. “She wore only contact lenses and had no glasses, an eye health danger. We steered her toward a small plastic frame that extends the front past the lenses before junction with the temples, which gives the illusion of width without adding size and bulk. The frame is also brightly colored, which distracts from the lens thickness.”

Sometimes, simple details may not add up, and investigation must ensue. “We had a patient who wanted new, thinner-looking glasses,” says Sam Morgenstern, optician and manager of The Optical Shoppe in Princeton, N.J. “She was wearing an FT28 in 1.67 material in a plastic frame. We picked out a smallish metal frame, keeping her in 1.67 FT28s.”

On delivery, the patient complained of not seeing clearly. Her old prescription was:

• OD: −12.75 – 0.75 x 14
• OS: −11.50 −1.50 x 142
• Add: +1.25

Her new prescription:

• OD: −12.75 – 1.00 x 19
• OS: −11.25 −1.75 x 150
• Add: +1.50

“They seemed close in prescription, materials, and design, PD was the same, and the seg heights were the same in relationship to her lower lid,” Morgenstern reports. “The pantoscopic tilts were the same.”

Comparing the frames led to the solution. Her old glasses, a plastic frame with no nosepads, fit closely to the patient's face, while the new frame—metal with nosepads—placed the frame farther away from her face. The difference in vertex distance was the culprit.

“This made the effective power of the new lenses less than what the doctor had ordered,” he concluded. “We refit the glasses so they'd sit closer to her face, and her vision was much improved. However, we couldn't fit the metal frame any closer to her eyes due to lens thickness, plus the pads couldn't be adjusted any more to fit the frame closer.”

Consultation with one of the practice's doctors determined the ultimate solution: Fit the frame at a normal distance from the patient's eyes and prescribe a compensated prescription for the new vertex distance. The successful, final prescription: OD: −13.25 – 1.25 x 19; OS: −12.00 −1.50 x 147; Add: +2.00. EB