Abstract
Abstract: :
Purpose:To determine the reproducibility of the results of eye movement compensated static fundus perimetry, and compare threshold values to those obtained with conventional automated achromatic perimetry. Methods:Ten healthy eyes of 10 subjects (22–34 years) with corrected visual acuity of >=20/20 were tested. Static threshold perimetry was performed with the MP–1 Micro Perimeter (Nidek Inc.) and with the Humphrey Field Analyzer II (HVF). To assess reproducibility with the MP–1, thresholds to "white" stimuli, (Goldmann III, 200 ms) presented at 40 locations in an array subtending a radius of 10 deg were obtained over three trials. In the first trial, the subject maintained steady central fixation of a red 3 deg cross. In the second, the subject was instructed to sequentially fixate the four ends of the cross, moving clockwise every five seconds, and in the third the subject again fixated centrally. For each subject, the results of the first trial were compared to the third to assess reliability, and the results for the steady central fixation trials were compared to those for the "unsteady" eccentric fixation trial. Threshold values were also obtained using a 10–2 program on the HVF and values were compared to those obtained with the MP–1. Results:For the MP–1, across all subjects, the maximum difference between the two steady fixation trials was 6.0 dB and this occurred at 2/40 locations for two subjects. The maximum difference between the steady and unsteady eccentric fixation trials was also 6.0 dB and this occurred at 3/40 locations for two subjects. The averaged differences between the steady and unsteady eccentric fixation trials for the 40 locations ranged from 0.1 dB to 1.59 dB (SDs 1.4 to 2.1dB) among subjects. A comparison between MP–1 and HVF dB values showed that they were higher at all locations with the HVF. This is due to the difference in maximum available light intensity between the MP–1 (400 asb) and the HVF (10,000 asb). Conclusions:Reproducible fundus perimetry of the central retina is possible with the MP–1. To compare results of the MP–1 to those of HVF a correction factor is necessary.
Keywords: visual fields • perimetry • macula/fovea