Optical coherence tomography angiography (OCT-A) can detect preclinical ocular changes in the capillary density (CD) and thickness of the retina and the optic nerve head in patients with primary pulmonary hypertension (PPH), researchers found in a study published in Retina.
Since traditional eye exams cannot detect minor changes in the fundus and fluorescein fundus angiography is invasive, researchers sought to investigate ocular abnormalities in patients with PPH, compared with those without PPH, using OCT-A.
The study included 44 eyes of 22 patients with PPH and 44 eyes of 22 patients without PPH. The researchers noted fundus changes in 4 patients with PPH (group 1). However, 18 (group 2) showed no changes. Eye exams, OCT-A, and color fundus photographs were obtained for all participants. The patients without PPH were labeled group 3.
The optic-disc associated CD was significantly reduced in group 1 compared with group 3. The perifoveal VD in the superficial retina and the parafoveal and perifoveal VD in the deep retina were lower in group 2 than group 3. RNFL thickness and ganglion cell complex (GCC) thicknesses were both reduced in group 1 compared with the other groups (RNFL group 1 vs group 2: 79.42±22.56 µm vs 98.491±11.100 µm; P =.000; vs group 3: 79.42±22.56 µm vs 101.338±11.249 µm; P =.000).
Focal loss volume (FLV) and global loss volume (GLV) were increased in Group 1 compared with the other groups Differences in the macular-associated VD, optic nerve–associated CD, RNFL thickness, GCC thickness, FLV, and GLV between Groups 1 and 2 were also statistically significant.
“Parameters such as the macular-associated VD, optic disk–associated CD, RNFL thickness, and GCC thickness may be useful for the early detection of microvascular and neural impairments in PPH patients with or without fundus changes,” the study says. “Moreover, the deep VD, including the parafoveal and perifoveal VD, and the RNFL and GCC thickness, may be sensitive predictors of ocular impairment in PPH patients without fundus abnormities.”
Gu S, Li Z, Zhang Y, et al. Optical coherence tomography angiography findings of microvascular and neural changes in primary pulmonary hypertension. Retina. 2021;41(4):784-792. doi:10.1097/IAE.0000000000002940