Título

MULTI-MODAL IMAGING IN A CASE OF ACUTE MACULAR NEURORETINOPATHY

Introdução / Purpose

Describe multi-modal imaging findings in a case of Acute Macular Neuroretinopathy (AMN).

Material e Método / Methods

Case report.

Resultados / Results

A 31-year old woman presented with acute onset of small scotoma in the right visual field. A review of her medications disclosed use of oral contraceptives. Examination showed corrected visual acuity of 20/20 and no changes on anterior segment biomicroscopy and ophthalmoscopy in both eyes. 10-2 visual field testing of right eye (OD) revealed a single scotoma point, consistent with her Amsler grid changes. Near infra-red (NIR) imaging of OD demonstrated a tear-drop shaped dark grey lesion. Spectral-domain optical coherence tomography (SD-OCT) showed subtle hyperreflectivity of the outer nuclear layer (ONL) and disruption of the underlying ellipsoid. There were no changes in fluorescein angiography and fundus autofluorescence. OCT Angiography (OCTA) was performed two months after the onset of the scotoma and revealed normal flow in all retinal capillary plexus and choriocapillaris.

Discussão e Conclusões / Discussion

AMN is a relatively rare condition with a presumable microvascular etiology. Main symptom is acute onset of paracentral scotomas. Ophthalmoscopy may show distinctive wedge shaped lesions or may have no clinically identifiable changes. NIR imaging in conjunction with SD-OCT may be the most sensitive imaging modality to diagnose AMN. AMN lesions appear hyporeflective with well-demarcated margins using NIR and are correlated with ellipsoid disruption on SD-OCT. OCT findings may also show hyper-reflectivity of the ONL or early hyper-reflective plaques at the border of the outer plexiform layer and ONL. While deep retinal capillary plexus ischemia has been proposed as the etiology of AMN, recent studies using OCTA suggest that choriocapillaris flow abnormalities may be associated with AMN. In our case, OCTA showed no changes; this may be related to a reperfusion of the region, or because ischemia may be located in intermediate retinal capillary plexus.

Palavras Chave

Acute macular neuroretinopathy; multi-modal imaging; ischemia; spectral-domain optical coherence tomography; near infra-red imaging; optical coherence tomography angiography