Multimodality imaging of retinal astrocytoma

Abstract

Purpose: Cross-characterization of retinal astrocytomas (RA) using ocular diagnostic imaging techniques.

Methods: Fundus photography, fluorescein angiography, optical coherence tomography, fundus autofluorescence images, and ultrasonography were used to define characteristics of RA.

Results: 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).

Conclusions: 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.