February 16, 2016
3 min read

Advanced autorefraction allows clinicians to provide ‘high definition’ vision

Two optometrists share their experiences with the PSF Refractor.

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Practitioners are finding that advanced refracting technology is proving to be more accurate than the traditional phoropter, increases patient comfort and confidence, and improves clinical results.

Derek Czywczynski, OD, told Primary Care Optometry News he has received only positive patient feedback when using Vmax Vision’s Perfectus, a smaller footprint model of the company’s PSF Refractor.

“They like the technology and the ease of making decisions,” Czywczynski, who practices in Hazen, N.D., said. “I’ve been told that the PSF makes them feel much more confident in the decisions they have made to get the best prescription possible. It saves time, especially on patients who have a tough time making decisions with the phoropter.”

Derek Czywczynski

The Perfectus combines the PSF Refractor with the PSF Integro, which reduces the refraction lane from a 16-foot by 20-feet space to a 3-foot by 4-foot space, Shui Lai, PhD, chief executive officer of Vmax (Maitland, Fla.), told PCON previously. He said the Perfectus also includes a wavefront autorefractor that uses point spread functions (PSFs) to achieve a more stable and repeatable refraction.

Czywczynski believes the PSF is more accurate than utilizing the traditional phoropter.

“Being able to refract to 0.05 D proves that point,” he said. “I’ve completed a refraction with the PSF and then utilized the phoropter on that same patient. The patient felt more comfortable with the PSF. I’ve also put the patient’s habitual glasses prescription in the PSF and compared those with my final results. That is usually the selling point to the patient when they see the comparison.”

Czywczynski noted the benefits of the Perfectus’ night vision option.

Kenneth Daniels

“I’ve had a few patients who have required different prescriptions based on day or night conditions,” he said. “It made a huge change with patients with early stage cataracts and even those who have had cataract surgery – not to mention that I can compare their day PSF final refraction with their night PSF refraction in a night-time setting.”

Kenneth Daniels, OD, FAAO, who has two practices in Hopewell and Lambertville, N.J., also shared positive results.

“The refraction is faster and more accurate,” he told PCON. “Further, it’s more beneficial when performing PSF refraction with difficult refractive cases or in pre- and postoperative care.”

Daniels said it varies from office to office as to who performs the refraction, an optometrist or technician.

“The technician is easily trained and can perform the exam as accurately as the clinician,” he said. “A trained refractionist can determine if technique needs to be adjusted based on patient response.

“For example, on more difficult refractions a more trained individual will know to go back to re-check axis if cylinder acceptance varies,” he added.


“The extra information is the true magic of the system,” Daniels continued. “It is the transfer of information to optimize the clinical results. We can transfer the PSF refraction to a digitally manufactured spectacle lens, addressing the higher-order aberrations not only for daylight hours but also evening. The transfer to the Vmax Encepsion lens allows the patient to appreciate a high definition sense to their vision in which we actually hear the patient say ‘Wow,’ which rarely occurs with standard surfaced lenses.”

According to the Vmax Vision website, the Encepsion is the only lens that can incorporate the highly precise prescription from the PSF Refractor.

Daniels also said he transfers this information to specialty contact lenses, such as Special Eyes (Sarasota, Fla.), and Wavetouch (Carlsbad, Calif.). “We design these lenses in conjunction with the iTrace (Tracey Technologies, Houston) to optimize all parameters and optics of the lens,” he added.

Daniels said he uses the PSF for over-refractions of contact lenses if there is a need to re-order for power optimization.

“Also important is pre- and postoperative care for cataract and cornea,” he continued. “When I can supply iTrace information with PSF refraction, this only enhances the surgeon’s ability to optimize the surgical plan and define greater outcomes.” – by Abigail Sutton

Disclosures: Czywczynski reports no relevant financial disclosures. Daniels reports no financial interest in the company. He has received lecture honorarium to discuss PSF Vmax products.