Schlötzer-Schrehardt et al. measured the activity and levels of MMP1, MMP2, MMP3, MMP7, MMP9, MMP12, TIMP1, and TIMP2 in the aqueous humor of patients with pseudoexfoliative glaucoma, primary open-angle glaucoma, and cataract [3]. Here, MMP1 is linked to open-angle glaucoma.