Abstract
Abstract: :
Purpose: The Peristat computer algorithm was employed in a comparative study for the detection of visual field defects. The Peristat is a perimetry system, which allows self-testing on any standard computer monitor with internet connection. Its efficacy and utility for screening of visual field defects was characterized in relationship to established visual field tests such as the Humphrey’s Visual field analyzer Methods: The study prospectively evaluated patients with an established glaucoma diagnosis as well as glaucoma suspects who had undergone comprehensive ophthalmologic examination including prior office perimetry evaluation (Humphrey Field Analyzer) and well documented visual field status. The inclusion criteria for this prospective, non-consecutive comparative series were: patients diagnosed with or suspect for glaucoma, best corrected visual acuity better than 20/200 and reliable performance on a prior standardized office perimetry. All of the glaucoma suspects were patients with high cup-to-disc ratios [>0.5] and borderline IOPs. A total of 40 eyes [of 23 patients] with severe, mild-moderate and no scotomas on standard perimetry were interrogated with the Peristat system. Of them, 18 eyes demonstrated severe glaucomatous field damage, 7 had mild-moderate defects and 15 had normal visual fields. Standard computer set-up was used with a 17" monitor, standard keyboard and mouse. The program was delivered through a remote connection with a server and the patients interacted unassisted with a browser-enabled interface Results: All of the patients completed the Peristat test without difficulty. The Peristat interrogated a visual field of 24 degrees from fixation in all patients. The results were reviewed in masked analysis by 2 glaucoma specialists and 1 general ophthalmologist. Each quadrant for every test was qualitatively examined for any defects which were subsequently quantified for the density of the scotomas. In comparison to the Humphrey test, the Peristat demonstrated a high degree of correlation. Among the three reviewers, sensitivity ranged from 76% to 77%. Similarly, test specificity was in the range of 94%-95%. The interobserver variability was minimal. Conclusions: The Peristat is a reliable test, which demonstrates high clinical efficacy for the detection of visual field defects at a fraction of the cost of standard office perimetry. In selected populations, the Peristat can be a valuable tool for cost-effective self-screening of visual field loss such as that occurring in glaucoma.
Keywords: clinical (human) or epidemiologic studies: tre • clinical (human) or epidemiologic studies: pre