Mean concentrations of cytokines in aqueous humour in patients with neovascular AMD before the first and third ranibizumab injections were as follows (in pg/mL): CXCL1, 8.4 and 3.3; IP-10, 110 and 55; CXCL12, 480 and 240; CXCL13, 9.2 and 2.6; MCP-1, 620 and 220; CCL11, 7.1 and 2.8; IL-6, 5.9 and 1.6; IL-10, 0.15 and 0.015 (all p<0.0001), and MMP-9, 0.92 and 1.5 (p=0.0216), respectively.
Additionally, the possible protective effect of CC genetic variant in MMP-9-1562C/T polymorphism against progression of age-related macular degeneration was observed.
Only MMP-9 Rs3918242 (C->T) single nucleotide polymorphism was found to play a significant role in the development of AMD, and the effect was more pronounced at the age of less than 65 years.
Longer microsatellites in the promoter of MMP-9 are associated to the exudative form of AMD and to body mass index, a well-known risk factor for the disease.
The localization of MMP-2 and MMP-9 to the areas of new vessel formation and to the enveloping Bruch's-like membrane, respectively, suggests that MMP-2 and MMP-9 may be cooperatively involved in the progressive growth of choroidal neovascular membranes in AMD.