[Angioarchitecture of small retinoblastomas: the role of optical coherence tomography angiography]

Optical coherence tomography angiography (OCTA) is a non-invasive diagnostic method used in children and adults. Features of angioarchitecture of small retinoblastoma are not sufficiently covered.

The study investigated the angioarchitecture of small retinoblastomas using OCTA.

The study included 10 children with binocular retinoblastoma aged 2.7±0.5 months with small tumors of central localization (10 foci). The tumors were divided into 3 groups: group 1 (n=4) - tumor thickness 0.8±0.2 mm; group 2 (n=3) - 1.6±0.5 mm; group 3 (n=3) - 2.4±0.8 mm. OCTA was performed on Spectralis HRA+OCT (2460 scans in total). Vessels were identified in the superficial, deep and outer layers of the tumor on En Face images. Their average number was estimated by visualization of yellow pixels in the superficial layers on 10 sagittal sections. Statistical analysis was done using Microsoft Excel, Statistica 8.0. The Kruskal-Wallis H test was used for comparative analysis of independent variables with more than two samples.

Retinal vessels with feeding anastomoses connecting them to multiple small tortuous tumor vessels in the superficial layers were identified in group 1. Number of yellow pixels - 16.5±0.5. In the deep layers - single chaotic vascular arcades. In flat small retinoblastomas the vascular component was not evaluated. In group 2 in the superficial layers of the tumor we found multiple geniculate vessels of large and small caliber anastomosing between themselves and the retinal vessels. Number of yellow pixels was 21±0.8. A few vessels were identified in the deep and outer layers. In group 3 we identified single convoluted vessels in the superficial layers with glow and quantity increasing in the deep layers. In the deep layers - emergence of a small number of vessels. The maximum number of multiple own tumor vessels was determined in the outer layers. Number of yellow pixels - 10±0.8.

The obtained results confirm the possibility to preclinically identify the angioarchitecture of small retinoblastomas in order to determine the activity of tumor growth and serve as a marker of neoplasm regression in the future, after organ-preserving treatment.