Abstract
Abstract: :
Purpose: frequency–doubling technology perimetry is a new perimetric test and has been developed to screen patients with glaucoma. This study’s purpose is to prospectively evaluate the learning effect in this new instrument, in healthy subjects and glaucoma patients. Methods: 14 healthy adults with no prior visual field experience and 18 glaucoma patients with prior visual field experience (Humphrey field analyzer) underwent two serial visual field tests using the N–30 program of the Zeiss–Humphrey FDT analyzer. Tests were spaced 2 to 30 days. The frequency–doubling perimetry presents stimuli on a black–and–with video monitor. During the N–30 full threshold program,19 points are tested (1 round one centrally, 16 square ones in the periphery up to 20°, and 2 more square ones in the nasal periphery from 20° up to 30°). To study the learning effect, the mean deviation and the threshold values of each test point for each patient were analyzed. Only one eye was chosen randomly. Results: The mean (± standard deviation) age was 63 ± 13 years for glaucoma patients and 48 ± 9 years for healthy subjects. The mean deviation average of the N–30 program improved by 0.501 decibels in healthy subjects, with statistically significant difference (p=0,041) and 0.002 decibels in glaucoma patients (no significant difference; p=0,528). No significant difference was observed considering any of the test points between the first and second session in glaucoma patients. In healthy subjects, there was a statistically significant difference in the sensitivity value between the first and second session in only one test point (relative to the most peripheral temporal inferior location) (p=0,045). Conclusions: There was a positive learning effect using the frequency–doubling technology perimetry, especially in patients with no prior visual field experience.
Keywords: perimetry • visual fields • intraocular pressure