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OD’s study shows hybrid keratoconus lens settles in 20 minutes
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NEW YORK – A hybrid contact lens from SynergEyes designed for eyes with keratoconus was shown to settle 30 microns to 60 microns in 15 to 20 minutes, according to a small pilot study conducted by Jeffrey Sonsino, OD, and reported here at Vision Expo East.
Sonsino shared his study results during the Global Contact Lens Forum.
“UltraHealth by SynergEyes is a second-generation reverse geometry lens with a posterior surface that allows vaulting of the apex of the cone,” he said. “It follows the optical fitting relationship of central clearance found in the CLEK [Collaborative Longitudinal Evaluation of Keratoconus] studies.”
Sonsino said that scleral and hybrid lenses are meant to vault the apex of the cone and settle over time.
“How much time do you have to allow that lens to settle on the eye before you evaluate it in the clinic?” he asked.
Optical coherence tomography or corneal topography performed too soon after insertion will produce a faulty reading, Sonsino said.
“The things you see in clinic every day are the things that lead to research studies,” he said.
Sonsino developed a prospective, nonrandomized, open-label, single-investigator pilot study to look at patients with keratoconus, both naïve and habitual wearers of UltraHealth lenses.
Sonsino quickly discovered a problem with the original study design: “You never know where on the cornea you’re looking at with OCT,” he said. “So, we devised a neat workaround to figure that out.”
He explained that he asked SynergEyes Specialty to manufacturer some UltraHealth lenses with a drill dot in the direct geometric center.
“Our hypothesis was that it didn’t matter where we were in the keratoconic eye because the lenses settle at the same rate; all I had to know was that I was at the right spot,” he said.
Sonsino said he took three OCT scans at the deepest portion, the left edge and the right edge on both the horizontal and vertical. Statistical analysis showed no significant difference among the six locations.
“Basically, this showed us that you could take a data point from any of these locations,” he said.
Sonsino found that the average settling plateaued over 60 minutes, “which was a good thing.”
Of the 10 patients evaluated, 30 microns to 60 microns of settling occurred in about an hour, and most of that occurred between 15 and 20 minutes.
“That changed my clinical practice,” Sonsino said. “We let them settle 20 minutes before taking OCTs. The study also showed us we needed only one measurement instead of six.” – by Nancy Hemphill, ELS, FAAO
Reference:
Davis R, et al. Evidence based eye care and clinical practice: A review of research in clinical practice. Presented at Vision Expo East, New York. March 30-April 2.
Disclosure: Sonsino reports he is a consultant for Alcon, Allergan, Contamac, Johnson & Johnson Vision Care, Optovue, SynergEyes, Visionary Optics and Visioneering. He is a principal in LVR Technology.