Clinical and Multimodal Imaging of Acute Outer Retinopathy Expanding the Spectrum of Acute Annular Outer Retinopathy.

Purpose: To describe the clinical features, multimodal imaging findings, natural history, and treatment outcomes of acute outer retinopathy (AOR), which represents an expanded spectrum of acute annular outer retinopathy (AAOR).

Design: Retrospective, observational, longitudinal, multicenter case series.

Participants: Twenty-three patients (15 female, 8 male) with a mean age of 41.8 ± 18.6 years (range: 14-86 years) and a mean follow-up duration of 3.7 ± 1.5 years (range: 1-12 years).

Methods: Clinical characteristics, multimodal imaging findings, laboratory evaluations, genetic testing, natural history, therapeutic management, and outcomes were reviewed and analyzed.

Main outcomes measures: Specific multimodal imaging signatures of AOR were identified, including findings from ophthalmoscopy, fundus autofluorescence (FAF), fluorescein angiography (FA), indocyanine green angiography (ICGA), and optical coherence tomography (OCT). Humphrey visual field testing, full-field electroretinography (ERG), and multifocal ERG were analyzed. Baseline features and the natural course of the disease were delineated.

Results: Thirty-eight eyes from 23 patients were analyzed. Presenting symptoms included photopsia (87%), blurred vision (57%), and scotoma (57%). On ophthalmoscopy, AOR was acutely characterized by yellow-greyish outer retinal lesions corresponding to hyperautofluorescent changes on FAF and the angular sign of Henle fiber layer hyperreflectivity (ASHH) on OCT. FAF imaging revealed ring-like hyperautofluorescent lesions surrounding the optic disc in 18% of eyes. Additional lesion patterns on FAF included perivenular (53%), sectoral (16%), and spot-like distributions (13%). FA and ICGA findings were mostly unremarkable. Lesion progression primarily occurred within the initial weeks following presentation and stabilized in size beyond this period in the majority of eyes. Over time, affected areas progressed to outer retinal atrophy with pigmentary changes. Foveal sparing was observed in 68% of the eyes. None of the therapeutic interventions appeared effective in halting the progression to complete outer retinal atrophy or preventing lesion enlargement.

Conclusions: AOR is characterized by early photoreceptor disruption, evidenced by ASHH on OCT, leading to rapid outer retinal atrophy and subsequent degeneration of the retinal pigment epithelium within the damaged zones. Although distinct patterns of lesion distribution were observed, their consistent features on multimodal imaging support their inclusion within a unified disease spectrum termed acute outer retinopathy.