Chorioretinal Side Effects of Therapeutic Ocular Irradiation: A Multimodal Imaging Approach

Abstract

Radiation chorioretinopathy, radiation maculopathy, and radiation optic neuropathy are the major complications of ophthalmic radiotherapy. Optical coherence tomography (OCT) and OCT angiography (OCTA) are revolutionary imaging methods, allowing the visualization of the retinal cellular architecture and the retinal vascular system, respectively. In recent years this multimodal imaging approach has been applied to several retinal disease, but its role in the clinical characterization of retinal complications secondary to ophthalmic radiotherapy has not yet been defined. The purpose of this review is to critically evaluate the role of OCT and OCTA in the clinical assessment of radiation-induced chorioretinopathy, maculopathy, and optic neuropathy.

Keywords: ocular oncology; optical coherence tomography (OCT); optical coherence tomography angiography (OCTA); radiation chorioretinopathy; radiation maculopathy; radiation optic neuropathy; radiation retinopathy.

Figure 1

Color fundus photography showing a laser-treated radiation chorioretinopathy, characterized by chorioretinal atrophy, ischemia, ghost vessels, cotton wool spots, hard exudates and retinal hemorrhages; hemorrhages and hard exudates involve both the macular region (radiation maculopathy) and the optic nerve (radiation optic neuropathy).

Figure 2

Color fundus photography showing radiation maculopathy in an advanced stage, characterized by chorioretinal and retinal pigment epithelium atrophy in the macular area.

Figure 3

Color fundus photography showing radiation optic neuropathy, characterized by optic disc edema, peripapillary hemorrhages and peripapillary exudates. The treated uveal melanoma is visible as a pigmented lesion inferior to the optic nerve.

Figure 4

Fluorescein angiography showing chorioretinal atrophy, ischemia (capillary non-perfusion) and abnormal perifoveolar capillary network.

Figure 5

Color fundus photography of a patient treated by panretinal photocoagulation because of radiation retinopathy secondary to brachytherapy for uveal melanoma. The treated uveal melanoma is visible as a pigmented lesion (inferior nasal quadrant).

Figure 6

Fluorescein angiography imaging demonstrating retinal neovascularization along the inferior temporal vascular arcades bordering ischemic areas.

Figure 7

Optical coherence tomography angiography (OCTA) analysis demonstrating perifoveal neovascularization.

Figure 8

OCTA analysis of the choriocapillary vascular structure in a patient affected by radiation chorioretinopathy in his left eye (A). Choroidal vessels are rarefied and dilatated; “signal void” spots are recorded in the central area. The normal appearance of the choriocapillary vascular structure of the fellow-eye is showed in (B).

Figure 9

Macular OCT showing cystoid macular edema with limited subfoveal neuroretinal detachment secondary to radiation maculopathy.

Figure 10

Macular OCT scans of radiation maculopathy before (A) and after (B) intravitreal treatment by dexamethasone implant: Complete resolution of macular edema was documented two months after treatment.

Figure 11

(A) Macular OCT linear scan in a patient affected by radiation maculopathy. (B) Macular OCT linear follow-up scan performed after intravitreal treatment by dexamethasone implant, showing the resolution of macular edema. (C) Magnification of figure A, showing hyperreflective intraretinal foci (yellow arrows). (D) Magnification of figure B, showing the reduction of hyperreflective intraretinal foci (yellow arrows).

Figure 12

OCTA imaging of the superficial (A,B) and deep (C,D) plexuses showing foveal avascular zone enlargement in the treated eye (A,C) compared to the healthy eye (B,D) in a patient treated by brachytherapy because of posterior uveal melanoma.

Figure 13

OCTA imaging of the superficial (A) and deep (B) capillary plexuses showing capillary dropout.

Figure 14

OCT imaging of patients affected by radiation maculopathy at different disease stages. (A) A patient affected by a relatively early-stage radiation maculopathy characterized by evident cystoid macular edema, having the vertical thickness of the largest macular cyst of 208 μm, and by the absence of the IS/OS layer disruption and RPE central atrophy (C208, J0, A0). (B) A patient characterized by an advanced stage radiation maculopathy characterized by evident cystoid macular edema having the vertical thickness of the largest macular cyst of 443 μm and by the presence of both the IS/OS layer disruption and RPE atrophy (C443, J1, A1).

Figure 15

OCTA imaging of the peripapillary area. The radial peripapillary capillary plexus (RPCP) of an eye affected by radiation optic neuropathy (A). Note the presence of peripapillary RPCP dropout. The contralateral healthy eye is showed in (B).