Evaluation of the Detectability of Early Glaucoma Using Humphrey Matrix

Abstract

Abstract: : Purpose: To evaluate the detectability of early glaucoma using Humphrey Matrix. Methods: Thirty–one eyes of 31 early glaucoma patients with mean deviation (MD) on Humphrey Field Analyzer (HFA; 24–2 program) more than –6 dB (mean age: 59.5±9.6 year, average MD: –2.1±2.2 dB), 26 eyes of 26 high–risk glaucoma suspects with cup–disc ratio greater than 0.7 and normal visual fields (mean age: 58.8±10.8 year, average MD: 0.4±1.3 dB), and 29 eyes of 29 normal persons (mean age: 54.7±13.6 year, average MD: 0.8±1.3 dB) were studied. All subjects were experienced with automated perimetry and had corrected visual acuity of at least 1.0 with no ocular media opacity. The 24–2 program of HFA and Humphrey Matrix were performed on each subject. The results of MD, pattern standard deviation (PSD), and glaucoma hemifield test (GHT) were compared between these groups. To compare the extent of visual field defects, the differences in number of probability symbols of total deviation between the two perimeters (Humphrey Matrix – HFA) were also compared in the three groups. Results: The MD on Humphrey Matrix were –6.3±4.0 dB in early glaucoma group, –1.9±2.3 dB in glaucoma suspect group and –1.4±2.3 dB in normal group, with a significant difference between early glaucoma and normal groups (p<.0001). The PSD on Humphrey Matrix were 5.9±1.9 dB in early glaucoma group, 3.3±0.7 dB in glaucoma suspect group, 2.9±0.7 dB in normal group, with significant differences between early glaucoma and normal groups (p<.0001) and between glaucoma suspect and normal groups (p=.02). The sensitivities were 100% in early glaucoma group and 50% in glaucoma suspect group when abnormality was defined as less than 5% significance level for MD or PSD, or ‘outside normal limits’ for GHT; whereas the specificity was 86%. The differences in number of probability symbols were 10.2±11.9 in early glaucoma group, 4.4±6.5 in glaucoma suspect group and 3.8±6.2 in normal group, with a significant difference between early glaucoma and normal groups (p=.01). Conclusions: Humphrey Matrix is effective to detect early glaucoma. The difference in extent of visual field defect between Humphrey Matrix and HFA may predict future deterioration of visual field.

Keywords: visual fields • perimetry • clinical (human) or epidemiologic studies: systems/equipment/techniques