Author: Catarina Ferreira (Portugal)
Co-authors: Catarina Cunha Ferreira, Ricardo Machado Soares, Joana Silva Fernandes, Teresa Shiang, Dália Meira, Lígia Ribeiro
Pulmonary hypertension (PH) is a rare disease characterized by an elevation in pulmonary artery pressure, leading to right heart failure and subsequent increase in systemic venous pressure. Adverse functional and structural changes in multiple organs may occur, and ocular involvement has been described. The suggested underlying mechanism for ocular complications in acute settings is retinal and choroidal congestion as a result of elevated venous pressure in the superior vena cava and, consequently, ophthalmic and ocular veins. These are considered rare events and affect mainly the posterior segment. In fact, the available literature on ocular involvement in PH consists mainly of case reports. In this study, an analysis of the retinal and choroidal vasculare in patients with PH using optical coherence tomography angiography (OCT-A) is made and compared with that of healthy sex and age-matched control subjects.
Ophthalmology Department, Centro Hospitalar Vila Nova de Gaia/Espinho, Vila Nova de Gaia, Portugal.
A cross-sectional study was performed at a tertiary practice Ophthalmology department. Patients with PH from the Pulmonology outpatient clinic and healthy control subjects were recruited. All participants underwent a comprehensive ophthalmological examination and an en face OCT-A using 15ºx15º macular scans (Spectralis, Heidelberg Engineering Inc.). OCT-A images were automatically segmented, and images from the superficial vascular plexus (SVP), intermediate capillary plexus (ICP), deep capillary plexus (DCP), choriocapillaris and choroid were retrieved. For a quantitative comparison of retinal and choroidal OCT-A imaging, vessel density, junction density and average vessel length were analyzed using AngioTool software (Center for Cancer Research, National Cancer Institute). A comparative case-control analysis was performed, and a correlation between disease duration and OCT-A parameters was made in the study group.
A total of 16 PH patients and 16 control subjects were enrolled. All PH patients had an established diagnosis and were under systemic treatment at the time of the study. Namely, 13 patients were classified as World Health Organization PH Group 1 and 3 patients as Group 4. Eyes in the study group had a significantly lower vessel density in both SVP and ICP compared to the control group (44.0%, interquartile range [IQR] 42.6 – 46.1% in the study group, 46,2%, IQR 44.5 – 47.6% in the control group, p=0.015; and 46.0%, IQR 45.0 - 47.0% in the study group, 47.1%, IQR 46.2 - 47.9% in the control group, p=0.035; respectively). Junction density in SVP layer was also significantly lower in the study group (0.0012, IQR 0.0011 - 0.0015 in the study group, and 0.0014, IQR 0.0012 - 0.0016 in the control group, p=0.047). No other significant differences were found between both groups in the analyzed vascular layers. No correlation was found between disease duration and OCT-A quantitative parameters in the study group.
To our knowledge, this is the first study to analyze the retinal and choroidal vasculature with OCT-A in PH. Small but significant differences were found between the study and control groups. In PH patients vessel density was lower in SVP and ICP, and junction density was lower in SVP. Although mostly described in acute settings, our preliminary OCT-A research suggests that retinal microvasculature is affected in PH even in patients with chronic and stabilized disease.
No financial disclosures.