MMP9 and retinal degeneration: Associations between MMPs and the IL-1 family have also been found in other retinal degenerations, with increased levels of MMP-1, MMP-9, MMP-12, and IL-1β found in the vitreous of patients with POAG (21), as well as elevated MMP-9 and IL-1Ra observed in the vitreous and tears of ROP infants (44).