EN FACE OPTICAL COHERENCE TOMOGRAPHY (OCT) AND OCT ANGIOGRAPHY FINDINGS IN RETINAL ASTROCYTIC HAMARTOMAS

To report spectral-domain optical coherence tomography, en face optical coherence tomography (OCT), and optical coherence tomography angiography findings in retinal astrocytic hamartomas.

Four cases of retinal astrocytic hamartomas, with small white or yellowish typical retinal mass, were imaged with fundus photography, intravenous fluorescein angiography, fundus autofluorescence, spectral-domain OCT, en face OCT, and OCT angiography.

The tumor was solitary in all cases and involved the posterior pole. It was idiopathic in three cases and was related to tuberous sclerosis complex in one case. The OCT findings included intralesional lucencies in two cases with no exudation. The tumor was within the retinal nerve fiber layer or deeper, usually overlying the inner plexiform layer providing a protusion in the vitreous cavity. Vitreous changes were present in all cases, corresponding to thickening and adhesion of the vitreous facing the lesion (two cases), apparent interdigitation with vitreous (one case), and marked condensation of the vitreous with interdigitations (one case). En face OCT imaging at the level of the retinal pigment epithelial zone showed a hyporeflective, round, well-delineated mass. A peripheral poorly defined hyperreflectivity with a central hyporeflectivity was observed at the level of mid-retina, likely because of shadowing effect. The OCT-A reveals a dense vascular network within the tumor.

Retinal astrocytic hamartomas may be well characterized by non-invasive imaging using spectral-domain OCT, en face OCT, and OCT angiography. The OCT angiography seemed to show tumor vascularity, which may represent dilated disorganized and anastomotic superficial and deep plexus capillaries. The tumor is often unique, peripapillary, small in diameter, and dome-shaped on spectral-domain OCT protruding into the vitreous cavity, responsible for vitreous changes facing the lesion.