Preliminary study on normal values of blue-on-yellow perimetry in central thirty degrees

Abstract

To investigate the normal values and related factors of blue on yellow perimetry (BYP) in the central 30 degree. A cross sectional study design was performed on this study. BYP was performed in a Humphery750II-i perimetry with 30-2 procedure and Fastpac strategy. The study samples consisted of 116 eyes of 58 normal subjects. The visual field indices were calculated and their related factors were analyzed. SPSS 13.0 software package was used for experiment data analysis. Comparison of three blue-on-yellow visual indices, including mean sensitivity (MS), mean defect (MD) and pattern standard deviation (PSD), were investigated by multi-way ANOVA with randomized block design method among four age groups. Relationship between age and visual field index was described and interpreted by calculating Pearson product-moment correlation coefficient and linear regression. Chi-square test was applied to determine the distribution of population and gender among four age groups. Significance level was set to alpha = 0.05. Values of the three different visual indices, MS, MD and pattern PSD, in central 30 degree of BYP were (21.23 +/- 2.96) dB, (-3.94 +/- 2.20) dB and (3.13 +/- 0.72) dB, respectively. The differences of MS, MD and PSD values between right eye and left eye were not statistically significant (F = 0.488, 0.833, and 0.677, with P = 0.487, 0.482 and 0.414, respectively). No differences in these three indices could be detected between male and female (F = 0.149, 0.547 and 1.948, with P = 0.702, 0.463 and 0.169, respectively). Significant difference in three visual field indices was identified among four different age groups (F = 48.160, 54.250 and 9.329, with P = 0.000, 0.000 and 0.032, respectively). The light average sensitivity in four quadrants showed statistically significant difference in all age groups (F value for quadrant factor was 81.544, P = 0.000). The MS value decreased 2.5 dB and the MD value increased -0.932 dB with the 10-year-old increasing. The average sensitivity in different eccentric ranges had a significant statistical difference (F value for eccentricity factor was 48.257, P = 0.000). The gender and the laterality do not affect the MS, MD and PSD in the BYP of normal subjects. The light average sensitivity is asymmetry in the four different quadrant, decreases in a linear decline with age and declines with the eccentricity.