Acute annular outer retinopathy: initial insights into clinical course variations with multimodal imaging.

Objective: To describe the clinical course and provide initial imaging perspectives in acute annular outer retinopathy (AAOR) by reviewing multimodal imaging (MMI) findings.

Methods: Observational case series study. Methods: Nine patients (12 eyes) with AAOR. Methods: Review clinical charts and MMI findings. Methods: Clinical medical records and multimodal imaging features via fundus photographs, optical coherence tomography (OCT), fundus autofluorescence (AF) and OCT angiography (OCTA), as applicable.

Results: Twelve eyes of nine patients (18-39 years) were identified. The clinical course was subdivided acutely progressive stage (APS), stationary stage (SS) and atrophic stage (AS) (1-3 weeks, 3 weeks to 3 months and >3 months, respectively). During APS, advancement of peripapillary annular band was noted in all eyes, accompanied by absent ellipsoid zone, increased choroidal thickness (ChT) and thinned outer nuclear layer (ONL) within the affected area. During SS, annular band disappeared on fundus photograph with improved ONL with improved ONL. During AS, affected area became depigmented with scattered pigmentation, exhibiting hyper-AF or mixed AF. Other manifestations included retinal atrophy and decreased ChT. OCTA revealed an enlarged foveal avascular zone in each stage, especially in AS. Seven eyes of 5 patients showed no macular involvement with best corrected visual acuity (BCVA) of 20/20, while 5 eyes of 5 patients showed macular involvement with poorer BCVA of HM-20/400 at the last visit.

Conclusions: AAOR mostly occurs in young individuals with unilateral involvement, especially in those with mild to moderate myopia. The observed variations in the clinical course of AAOR, documented through MMI, aid in the prompt recognition and understanding of this rare entity.