Impact of learning effect on reliability factors and global indices in visual field testing by standard automated perimetry in normal healthy subjects and primary open-angle glaucoma patients to obtain an accurate baseline perimetry chart

Purpose: To record and evaluate the reliability parameters (fixation loss (FL) %, false positive (FP) %) and global indices (mean sensitivity (MS), mean deviation (MD), pattern standard deviation in dB) in three visual field test sessions within two weeks to assess the learning effect in normal healthy subjects and POAG patients and comparison of learning effect gender wise and age wise in primary open?angle glaucoma (POAG) patients. Methods: This study was a prospective observational study. An oculus visual field testing was done and analyzed in 30 eyes of POAG patients and 30 eyes of normal healthy subjects in three visits. Results: There were 16 (53.3%) males and 14 (46.6%) females in the POAG group and 16 (53.33%) males and 14 (46.66%) females in the normal healthy subject group. A significant difference in data change between each visit in FL, FP, MD, MS was found though the difference was more pronounced in the second visit than in the third visit. The pattern standard deviation does not change significantly in subsequent visits in both groups. Gender wise and age wise no significant difference was found in the POAG group. Conclusion: Significant improvement in reliability parameters and global indices with each subsequent visit in both the POAG group and normal patients signifies the importance of learning effect on these parameters and the need to perform at least three tests to get the baseline perimetry chart, especially in POAG patients, while in normal subjects, second perimetric result can be accepted. It was also concluded that the learning effect is not influenced by age and gender.

Visual Fields in Normal Korean Measured with Humphrey Field Analyzer

Central 30-2 threshold tests were performed in 124 eyes of 62 normal subjects with Humphrey Field Analyzer. The average value of foveal threshold, mean deviation(MD), pattern standard deviation(PSD), shor-term fluctuation(SF) and corrected pattern standard deviation(CPSD) were 34.3+/-2.6dB, -1.96+/-1.31dB, 2.25+/-0.88dB, 1.38+/-0.52dB and 1.41+/-1.10dB, respectively. The frequency of abnormal value on automated perimetry(p<5%) was 25.5% in foveal threshold and 19.1% in MD, which was higher than fundamental data of perimetry. As the age increased, foveal threshold decreased (r=-0.729), PSD and CPSD increased (r=0.422) and 0.385, respectively) ; these are statistically significant correlations(p<0.05). This study has the limitation that test was performed on single session and had small study group. Therefore, further study is needed with comparative analysis following repeated test and larger group of visual field examination.

OCTOPUS Program G1 in Normlid Subjects

To determine the normal interindividual variability of global visual field indices in normal subjects and investigate the correlations of visual field changes with intraocular pressure and myopic degrees, OCTOPUS 2000R automated perimetry was tested in 70 eyes of 40 normal subjects who had undergone one previous visual field on two separate sessions. The average value of Mean Defect(MD) was 3.83 +/- 1.15dB. Three eyes(4.3%) were within 2dB of the normal. In the statistical analysis of Global indices between the 1st and the 2nd fields. there were no differences(p>0.05). MD and myopic degrees showed a significant positive correlation (r=0.237, p<0.05). These results indicate that visual field indices should be interpreted with caution and used as one adjunctive parameter with other clinical findings.