Fluctuation in Automated Perimetric Threshold in Korean.
- Author:
Sung Chul LEE
1
;
Sueng Han HAN
;
Hong Bok KIM
Author Information
1. Department of Ophthalmology, College of Medicine, Yonsei University, Seoul, Korea.
- Publication Type:Original Article
- MeSH:
Contrast Sensitivity;
Glaucoma;
Humans;
Refractive Errors;
Retinaldehyde;
Visual Field Tests;
Visual Fields
- From:Journal of the Korean Ophthalmological Society
1988;29(4):579-584
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
The purpose of a static visual field examination is primarily to establish the contrast sensitivity for a large number of retinal points at a defined background luminance, spot size and exposure duration. The light threshold is defined as the value at which the probability for a stimulus to be detected is 50%. This implies that scatter of the threshold value determined by quantitative perimetry is always present. When the visual threshold is measured several times at a location, the result is not always identical. The variability of the threshold value obtained has been termed "fluctuation". The amount of fluctuation is influenced by the visual sensitivity at the location, by whether the location is normal or defective, by the frequency of the patient's false positive and false negative responses in catch trials, and by the refractive errors, and by the size of target. The mean fluctuation of normal subjects was 2.69 +/- 1.60 dB, the mean fluctuation of glaucomatous patients was 4.32 +/- 1.56 dB. Using the independent t-test to compare groups individually, the difference between the patients with glaucoma and the normals was significant for all components(p<0.05). This study also shows that the fluctuation of peripheral visual field is greater than that of central visual field, and that in eyes with poor cooperation, the fluctuation is greater than in eyes with better cooperation(p<0.05). Using the dependent t-test to compare groups individually, the difference between the subjects with refractive correction and inaccurate refractive correction was not significant for all components(p>0.05). Using the dependent t-test to compare groups individually, the difference between the subjects with using target III and target IV was not signifficant for all components(p>0.05).
