Purpose: To examine progressive visual field loss in relation to disc hemorrhage (DH) and enlarged nerve fiber layer defects (NFLDs) in normal-tension glaucoma (NTG).
Subjects and methods: There were 106 eyes of 106 NTG patients (mean follow-up: 9.1 years) with well-defined NFLD borders and at least 3 years of follow-up. Examination was performed on their rate of visual field loss (MD slope and hemifield TD slope) and their rate of NFLD angle enlargement. For the NFLD angle, we took color fundus photographs and converted color photos into black-white photos extracted the blue ingredient. The midpoint between the fovea and the disc center was determined. The center was established as the disc, and the distance to the midpoint was established as the radius of a circle. The NFLD angle was defined as the angle formed by the two points where this circle intersected the NFLD and a third point which was the disc center.
Results: DH was seen in 51/106 (48.1%)cases and it occurred 1.28 +/- 1.99 times. In the DH group, the MD slope was -0.30 dB/year, indicating a significantly faster rate of visual field loss than that of the non-DH group (-0.13 dB/year); the rate of NFLD enlargement was 1.90 degrees/year, indicating a significantly faster rate than that of the non-DH group at 0.64 degrees/year. As the occurrence of DH increased, the TD slope (r = -0.263, p = 0.0056) and the rate of NFLD enlargement (r = 0.410, p<0.0001) increased significantly.
Conclusion: Examination was performed on NTG eyes with well-defined NFLD borders which were divided into the groups of with and without DH. The DH eyes had a faster rate of NFLD enlargement and faster progression of visual field loss compared with the non-DH eyes. In addition, the rate of NFLD enlargement and progression of visual field loss increased in the cases with frequent DHs.