Multimodality imaging of retinal astrocytoma.

Abstract

Cross-characterization of retinal astrocytomas (RA) using ocular diagnostic imaging techniques. Fundus photography, fluorescein angiography, optical coherence tomography, fundus autofluorescence images, and ultrasonography were used to define characteristics of RA. Thirteen patients had sporadic RA and 12 had tuberous sclerosis. Of the latter, 1 patient had multiple (n = 14), bilateral tumors and was excluded so as not to skew the analysis. Of those patients with a solitary RA, 63% were juxtapapillary. All were white to yellow. A mulberry-shaped surface was observed in 33%. Fluorescein angiography revealed intrinsic tumor vessels and late diffuse tumor staining in 42%. Optical coherence tomography revealed cells spreading from the tumor surface into the vitreous (75%), intraretinal fluid (25%), and multiple, ovoid hypolucencies within the tumor stroma (54%). Fundus autofluorescent imaging revealed that hypolucencies were hyperautofluorescent and solid tumor stroma appeared hypoautofluorescent. B-scan imaging revealed moderate to high internal tumor reflectivity (100%) with orbital shadowing (46%). Optical coherence tomography revealed a mean tumor thickness of 0.8 mm. Ultrasound imaging showed a mean thickness of 1.4 mm (range 1.0-1.7). Of the 21 patients subsequently followed in our centers, no tumor growth was noted (mean 54 months, range 1-96). This study reveals unique characteristics of RA and suggests that RA were most commonly amelanotic, moderate to high echoic, ≤1.7 mm in thickness, near the optic disc, and nonprogressive. When observed, a mulberry-shaped surface was pathognomonic.