AIF1 and glaucoma: Furthermore, Bosco et al. (2011) and others reported that a peak of microglia clustering and IBA1 expression in the central retina and optic nerve head (ONH) was detected in the chronic inherited DBA2J mouse glaucoma model at 3 months of age, preceding detectable RGC degeneration [80–82]; by 12 months, microglial cells were drastically reduced in their numbers and levels of IBA1 expression were decreased in the retina and ONH.