GFAP and glaucoma: Glaucoma optic nerve cross-sections from the same representative subjects as described above had significantly brighter GFAP fluorescence (48.64AU ± 7.406 vs 36.97 AU ± 5.397, p < 0.0001, CI 95% 9.048, 14.29) (Fig. 5A and B, Fig. 4A in red).