Differences in retinal vascular parameters between pediatric patients with inflammatory bowel diseases and healthy controls measured by optical coherence tomography angiography

Introduction
Crohn’s disease and ulcerative colitis, chronic inflammatory bowel diseases, can lead in some patients to extra-intestinal manifestations within the eye. Due to coagulation abnormalities in the course of inflammatory bowel disease (IBD), severe impairment in retinal blood vessels and circulation can be present.

Aim of the study
To assess the vascular network parameters in retinal and choroidal vessels with optical coherence tomography angiography (OCTA) in pediatric IBD patients and compare the obtained results with healthy controls.

Material and methods
Eighteen pediatric patients diagnosed with IBD in the remission state and 10 healthy controls were enrolled in the study. The near and distant visual acuity, cycloplegic refraction, intraocular pressure, and anterior and posterior eye segment were examined in every child. OCTA retina images in the 3 × 3-mm square centered on the fovea were obtained using the Optovue RTVue XR Avanti. The superficial capillary plexus layer (SL) and deep capillary plexus layer (DL), and the size of the superficial (SFAZ) and deep foveal avascular zone (DFAZ) were calculated. Whole image, foveal and parafoveal vessel density for the superficial and deep plexus of the retina (SVD-Whole, SVD-Fovea, SVD-Pfovea; DVD-Whole, DVD-Fovea, DVD-Pfovea) were calculated.

Results
A statistically significant difference was found in the foveal avascular zone (FAZ) area within the deep plexus. The vascular density in the whole image was significantly higher in the IBD group compared to the control group in the superficial plexus. The flow area in the superficial capillary plexus was increased considerably.

Conclusions
Superficial microvasculature parameters differ in pediatric IBD patients from healthy controls. The microvascular circulation in the posterior eye segment is changed in the course of IBD even though there is no clinical manifestation.