MMP9 and primary angle-closure glaucoma: The MMP9 rs3918249, rs3918242, and rs3918254 (not included in our study) polymorphisms were associated with a higher risk of developing POAG and primary angle-closure glaucoma in the North Indian [36] and Chinese populations [27], while rs3918249 may have a protective role for open-angle glaucoma in the Caucasian population [23,37].