Abstract
Purpose :
Pulmonary arterial hypertension (PAH) is characterized by systemic inflammation, endothelial dysfunction, and smooth muscle cell hypertrophy. PAH is classically considered an isolated small vessel vasculopathy of the lungs with peripheral pulmonary vascular obliteration. Diagnosis and monitoring of PAH patients require frequent procedures, including invasive hemodynamics with an average time to diagnosis of over two years after symptom onset. Systemic manifestations of PAH are increasingly acknowledged, but data remains limited. We hypothesized that retinal vascular changes could be associated with markers of PAH severity.
Methods :
Using VESsel GENerational Analysis (VESGEN), a non-invasive, user-interactive computer software that assigns branching generation of large (1) to small (9) vessel.
Results :
We examined fluorescein angiograms from controls (n=6) and group 1 PAH subjects (n=9) and correlated retinal vessel parameters with pulmonary hemodynamic endpoints from right heart catheterization. The tortuosity of PAH retinal vessels increased compared to controls ( P<0.001). Retinal vessel area density, a vascularity indicator, correlated negatively with right heart catherization hemodynamics (right atrial pressure , (p=0.04, r=-0.50; mean pulmonary arterial pressure, p=0.02, r=-0.55; pulmonary capillary wedge pressure, PCWP, p=0.0017, r=-0.72. PCWP also negatively correlated with arterial density (p=0.04, r= -0.51). Smaller, more fragile vessels (generations 6-9) correlated positively with vessel area density, superior vena cava oxygen saturation (SVCO2) (p= 0.04, r= 0.53), and pulmonary arterial oxygen saturation (PAO2) (p=0.01;r= 0.70). Normal vessel tortuosity that typically ranges from 1 to 1.15 pixel/pixel was greater in PAH arteries (1.17 ± 0.041) and veins (1.17± 0.040).
Conclusions :
In conclusion, we show that 1) reduced retinal vascularity (density) was associated with worsening pulmonary hemodynamics and 2) higher than normal tortuosity in PAH subjects. This investigation suggests that retinal changes may be associated with PAH severity. Use of FA and VESGEN in PAH is feasible and may facilitate early, non-invasive detection of PAH by careful determination of changes in retinal vessel tortuosity.
This is a 2021 ARVO Annual Meeting abstract.