Clinical features of acute macular neuroretinopathy

Abstract

Objective To observe the clinical features of acute macular neuroretinopathy (AMN). Methods Six patients (11 eyes) with AMN were included in this study, with every 2-week follow-ups till six months. Among them, five had preceding dengue fever (83.3%), one had history of head trauma (16.7%). All patients received routine examination, fundus photography, infrared reflectance (IR) imaging, spectral-domain optical coherence tomography (SD-OCT) scanning and fluorescein fundus angiography (FFA) initially, and fundus photography, IR, SD-OCT during follow-up. Results Sudden onset of central/paracentral scotoma in one eye or both eyes was the main visual symptom. There were 1 eye with normal fundus, 2 eyes with wedge-shape lesions, 8 eyes with yellow-white or brown sheet lesion. IR imaging demonstrated localized areas of hypo-reflection in the macula. SD-OCT scanning through these areas revealed hyper-reflection in the photoreceptor layer and disruption of its normal reflective structures. Subsequent SD-OCT demonstrated that the hyper-reflection of the photoreceptor layer regressed gradually, followed by thinning of the outer nuclear layer. The external limiting membrane and ellipsoid zone became continuous; however, the interdigitation zone was not restored. There was no remarkable findings of the AMN lesions on FFA. The scotomas persisted in all 6 patients (11 eyes) by the last visit. Conclusions IR imaging demonstrated localized areas of hypo-reflection in the macula. SD-OCT revealed hyper-reflection in the photoreceptor layer in acute stage and the interdigitation zone was not restored in late stage. AMN has a relative poor prognosis with persistent scotomas through at least 6 months. Key words: Macula lutea/injuries; Retinal diseases/ diagnosis; Disease attributes