Elevated aqueous humour tissue inhibitor of matrix metalloproteinase-1 and connective tissue growth factor in pseudoexfoliation syndrome

Background/aims: Pseudoexfoliation syndrome (PXF) was recently found to be associated with increased expression of transforming growth factor β1 (TGFβ1) in the aqueous humour. As concern has been raised regarding anti-TGFβ therapy, which can potentially disrupt the maintenance of anterior chamber asso-ciated immune deviation, the authors explored the levels of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), matrix metalloproteinase-9 (MMP-9), and connective tissue growth factor (CTGF) in aqueous humour to determine if these may represent alternative therapeutic targets. Methods: Aqueous humour samples were collected from patients who underwent routine cataract surgery. All patients were categorised into three main groups—PXF, uveitis, and control. The PXF group was further subcategorised into three grades based on the density of the exfoliative material observed on biomicroscopy, as well as the presence or absence of glaucoma. TIMP-1, MMP-9, and CTGF levels were measured using specific enzyme immunoassays (ELISA). Results: Eyes with PXF had significantly higher aqueous humour TIMP-1 concentration (n = 56, mean (SE), 9.76 (1.10) ng/ml) compared with controls (n = 112, 5.73 (0.43) ng/ml, p