MMP9 and Keratoconjunctivitis sicca: Examining the level of MMP-9, a common dry eye marker [12], pre-OP (8.81 ± 8.20 pg/mL), 5 days post-OP (2.01 ± 3.53; p = 0.088), and 90 days post-OP (8.32 ± 11.17; p = 0.986), revealed no significant differences between these examination points (Figure 2A).