Retinal Neurovascular and Choroidal Changes in Pediatric Patients with Cyanotic Congenital Heart Disease: A Multimodal Analysis

Background: To compare retinal capillary density, foveal avascular zone (FAZ) area, and the thicknesses of the peripapillary retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), and choroid between children with cyanotic congenital heart disease (CCHD) and healthy controls using multimodal optical coherence tomography±angiography (OCT/OCTA). We also examined correlations between these ocular metrics and hemoglobin, hematocrit, and oxygen saturation. Methods: This prospective, age- and sex-matched case–control study enrolled 21 children with CCHD and 21 healthy controls. Retinal capillary density in the superficial and deep capillary plexuses (SCP/DCP) and FAZ area were quantified with OCTA. Peripapillary RNFL, GCC, and choroidal thicknesses were measured with spectral-domain OCT (SD-OCT). To avoid inter-eye correlation, only right-eye data were analyzed. Results: Compared with controls, children with CCHD had a thinner choroid subfoveally and at 1,500 µm nasal and temporal to the fovea (all p<0.001), lower global peripapillary RNFL thickness (p=0.018) with a pronounced inferior-sector deficit (p<0.001), and reduced vessel density in both SCP and DCP (p=0.001 and p<0.001, respectively). In correlation analyses, higher oxygen saturation was associated with greater choroidal thickness at all locations (subfovea p<0.001; nasal 1,500 µm p=0.002; temporal 1,500 µm p=0.001), higher global (p=0.033) and inferior-sector (p<0.001) RNFL thickness, and higher vessel density in SCP and DCP (p=0.003 and p<0.001, respectively). Conversely, higher hemoglobin and hematocrit were associated with a thinner choroid (hemoglobin: subfovea p<0.001, nasal p=0.003, temporal p<0.001; hematocrit: subfovea p<0.001, nasal p=0.002, temporal p<0.001), lower global (hemoglobin p=0.017; hematocrit p=0.012) and inferior-sector (both p<0.001) RNFL thickness, and lower vessel density in both plexuses (SCP: hemoglobin p=0.004, hematocrit p<0.001; DCP: both p<0.001). The FAZ area was inversely associated with oxygen saturation (p=0.009) and positively associated with hemoglobin (p=0.048). GCC thickness did not differ between groups. Conclusions: In pediatric CCHD, retinal capillary density is reduced, the choroid is thinner, and peripapillary RNFL thickness is decreased-while GCC is preserved. Oxygen saturation shows positive associations with these ocular measures, whereas hemoglobin and hematocrit show negative associations. These findings indicate that multimodal OCT/OCTA can detect subclinical ocular involvement and may serve as a noninvasive adjunct for longitudinal monitoring.