Higher waveform scores linked to corneal hysteresis in glaucoma
Corneal hysteresis correlated with optic nerve head cupping in patients with glaucoma who had a waveform score measurement of 4 or higher but not lower scores.
Scott Schwartz, OD, from Dr. Schwartz Optometrist Associates in Sterling Heights, Mich., and his colleague Milton M. Hom, OD, FAAO, a private practitioner in Azusa, Calif., sought to explore this correlation, as corneal hysteresis has been described as associated with both the risk for developing glaucoma and for glaucoma progression.
“Dr. Hom and I set out to look at some of the new equipment we had and figure out if we were seeing what the science told us we should,” Schwartz said during his ARVO presentation. “We both had tonometers that gave us hysteresis measurements and we wanted to look at when the information was both helpful and correlated to other information in the scientific literature.”
Schwartz and Hom enrolled patients with glaucoma or suspected glaucoma for a total of 136 eyes. Using the Ocular Response Analyzer (ORA, Reichert), they found that corneal hysteresis correlated with cupping in all groups with a waveform score of at least 4, and the correlation increased at higher scores. There was no correlation in scores less than 4.
“We were able to confirm that corneal hysteresis can be helpful in glaucoma diagnosis due to its correlation to optic nerve head cupping but that this is only valuable if the reliability is high enough to be useful,” Schwartz concluded. “Clinically, this demonstrates that if using the ORA, if a measurement has a waveform score of less than 4, the data is likely not reliable and should be repeated.”
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Schwartz S, Hom MM. Clinical optic nerve head implications of waveform score in measurement of corneal hysteresis. Presented at: Association for Research in Vision and Ophthalmology meeting; May 6, 2020 (virtual meeting).
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