MMP2 and dry age related macular degeneration: In studies on ARPE-19 cells, repeated exposure to a non-lethal hydroquinone concentration (100 μM) or a single-dose of 100 μM hydroquinone for 6 or 18 h reduced the activity of MMP-2 and increased the accumulation of ECM proteins, effects which were associated with the progression of dry AMD [49, 50].