Multimodal Imaging in Iris Vascular Tumors: A Case Series

Abstract

Iris vascular tumors are very unusual and tend to affect middle-aged and older adults. We report a case series of four adult patients with vascular alterations of the iris. Two patients were diagnosed with simple iris arteriovenous malformation (IAVM) and two with iris microhemangiomatosis (IM). Although the diagnosis is typically clinic, multimodal imaging techniques, especially anterior segment fluorescein angiography (AS-FA), anterior segment optical coherence tomography (AS-OCT), and optical coherence tomography angiography (OCT-A), improve the accuracy and delimitation of their attributes and extension. Differential diagnosis with angle or iris neovascularization, melanoma, and other iris vascular tumors is essential to avoid unnecessary tests and treatments.

Keywords: diagnosis; iris arteriovenous malformation; iris microhemangiomatosis; iris vascular tumor; multimodal imaging.

Figure 1. First patient

Iris arteriovenous malformation under biomicroscopy (A) as a dilated tortuous iris vessel (black arrow) with a looping course in the iris periphery. Corresponding anterior segment optical coherence tomography (B) shows poorly defined hyporeflective spaces in the iris stroma (white arrow). Early fluorescein angiography (C) exposes a lesion that fills with contrast; it does not present leaking (white arrow).

Figure 2. Second patient

Iris arteriovenous malformation under slit-lamp photograph (A); there is a dilated tortuous iris vessel (white arrow) with a looping course from the periphery. An episcleral sentinel vessel (black arrow) is seen at that same level of the lesion. Corresponding anterior segment optical coherence tomography (B); the uniform vascular caliber and the serpentine course of the vessel are well visualized in the iris stroma (white arrow).

Figure 3. Fourth patient

Iris microhemangiomatosis. Slit-lamp examination (A) shows multiple small vascular dilations in the pupillary margin (black arrows) of the right eye and corticonuclear cataract. Fluorescein angiography presents many early hyperfluorescent spots in the pupillary margin (white arrow) (B), with minimal diffusion of dye in the late stage (C). Anterior segment optical coherence tomography (D) locates the lesions in the posterior stroma of the iris (white arrow).