In processing patients, efficiency is important, but according to a new study, some of that efficiency might come at the expense of reliability. At issue are three visual fields testing methods: standard (SS), Swedish interactive thresholding algorithm (SITA) and faster (SFR). Researchers affiliated with the University of New South Wales in Australia looked at one randomly selected eye each from 364 patients: 77 normal patients, 178 glaucoma suspects and 109 with glaucoma.

They found that, although SFR can save significant time compared with SS, 29.3% of SFR results were unreliable. Using the SS method, only 7.7% were unreliable. SFR resulted in higher sensitivity values (on average 0.5dB for glaucoma patients), which was greater under conditions of field loss (<19dB).

“Clinicians should be cognizant of false positive rates and seeding point errors as common sources of error for SFR,” the researchers concluded in their paper on the study. “Results between algorithms are not directly interchangeable, especially if there is a visual field deficit below 19dB.”

Phu J, Khuu S, Agar A, Kalloniatis M. Clinical evaluation of SITA-Faster compared to SITA-Standard in normal subjects, glaucoma suspects and glaucoma patients. Am J Ophthalmol. August 27, 2019. [Epub ahead of print].