Characteristics of visual field defects in primary angle-closure glaucoma

Abstract

To determine the difference of visual field defects between acute angle-closure glaucoma (AACG) and chronic angle-closure glaucoma (CACG) and to analyze the difference in the changes of visual field between primary angle-closure glaucoma (PACG) and primary open angle glaucoma (POAG). This retrospective case series study consisted of 53 patients with CACG,42 with AACG, and 42 with POAG. Visual field tests were examined using the 30-2 threshold program of the Humphrey Visual Field Analyzer. All cases with eligible visual fields were scored from 1 to 11 with the modified criterion used by Advanced Glaucoma Intervention Study (AGIS scores, mild groups: 1-5 and moderate groups: 6-11). An upper hemifields, lower hemifields, nasal area and overall field, mean defect (MD) and pattern standard deviation (PSD) were calculated and compared among the three glaucoma groups. The difference in central 10 degrees (12 points) of visual field damage, the nasal area, and the most defect quadrant of static visual field in each groups were evaluated. All analyses were performed with SAS 9. 1 software. The factor analysis was used to analyze significant differences in mean defect (MD), pattern standard deviation (PSD), VF scores of nasal area and overall field among the three glaucoma groups. Analysis of variance were assessed differences between VF scores of the superior hemifield and the inferior hemifield. The differences in central 10 degrees of visual field damage, the nasal area and the most defect quadrant of static visual field in each groups were examined using a chi-square test. P < 0.05 were considered to be statistically significant. (1) VF scores with inferior hemifield in POAG were lower than in CACG (t = 4.24, P = 0.0000) and in AACG (t = 3.28, P = 0.0013); There were no significant differences of VF scores between the superior hemifield and the inferior hemifield in CACG (t = 1.35, P = 0.1808) and AACG (t = 0.55, P = 0.5824). There was found a significant differences of VF scores between the superior hemifield and the inferior hemifield in POAG (t = 6.52, P = 0.0000). The CACG cases had a significantly greater amount of PSD than acute angle-closure glaucoma (P < 0.05). (2) There was found a significant differences in the number of patients with central visual field damage among the three glaucoma groups (chi2 = 10.385, P = 0.006). The POAG cases had the greatest rate of central visual field damage (52.38%), followed by acute angle-closure glaucoma (47.62%), the central visual field of CACG is the least suffered (22. 64%). (3) The nasal area was the most commonly involved area in the early stage of glaucoma. There were no significant differences among three groups (chi2 = 2.518, P = 0.641). There were no different distribution in the most defect quadrant of static visual field in different types of glaucoma (chi2 = 1.573, P = 0.954). Using AGIS scores, AACG had more diffused visual field damage than CACG and had more severe defect of the central visual field, while the damage of superior and the inferior hemifield in PACG are similar to POAG.