Interestingly, Maruichi et al. measured the intravitreal enzymatic activity of chymase and angiotensin-converting enzyme (ACE), both of which are related to angiotensin II (Ang II) generation, and revealed that chymase and ACE were activated in idiopathic macular diseases (i.e., macular hole and ERM) and PDR, respectively14. Here, ACE is linked to macular holes.