“…4,5 Based on available evidence, the ocular manifestations of PAH including, uveal effusion syndrome, exudative retinal detachment, venous stasis retinopathy, central retinal vein occlusion, choroidal detachment, delayed choroidal perfusion on fluorescein angiography, are thought to be related to the venous hypertension, causing circulatory disorders and thrombotic events, primarily in choriocapillaries. [6][7][8][9][10][11][12][13][14] In a recent study, Nickel and colleagues reported that PAH may be associated with an increase in retinal microvascular tortuosity. 15 Although this recent evidence has shown that the vasculature of the retina and pulmonary circulation share some common characteristics, to our knowledge, no study has investigated the possible relationship and interaction between retinal microcirculation and hemodynamic measurements of pulmonary circulation in patients with PAH.…”