We first examined the global relationship between GCL soma density and GC-IPL capillary density in all 12 subjects (
Fig. 2). Among the six control subjects, the average GCL soma density decreases across the macula from 4 to 5 cell layers deep at 3°T (25,058 ± 4649 cells/mm
2), to 2 to 3 layers at 6°T (15,551 ± 2301 cells/mm
2), to a monolayer at 12°T (3891 ± 1105 cells/mm
2; see
Fig. 2A).
17 Subjects with glaucoma followed the same trend but had lower GCL soma density than control subjects across all three locations: 3°T (12,799 ± 7747 cells/mm
2), 6°T (9370 ± 5572), and 12°T (2134 ± 1494; see
Fig. 2A). The difference between mean control and glaucoma GCL density was significant at each eccentricity (
P value < 0.05). The GC-IPL capillary density also decreased as a function of eccentricity in a similar trend among subjects with glaucoma and control subjects (
Fig. 2B). The capillary density was 0.27 ± 0.03 (3°T), 0.22 ± 0.03 (6°T), and 0.19 ± 0.03 (12°T) for subjects with glaucoma and 0.30 ± 0.04 (3°T), 0.26 ± 0.04 (6°T), and 0.18 ± 0.03 (12°T) for control subjects. The difference between mean control and glaucoma GC-IPL capillary density was not significant at any eccentricity (
P value = 0.10, 0.06, and 0.89).
Figure 2C shows the global relationship between GCL soma density and GC-IPL capillary density in control subjects and subjects with glaucoma not accounting for eccentricity or soma size. The coefficient of determination was relatively high for control subjects (pseudo R
2 = 0.59) and much lower for subjects with glaucoma (pseudo R
2 = 0.22).