Spontaneous remission of acute zonal occult outer retinopathy: follow-up using adaptive optics scanning laser ophthalmoscopy.

PURPOSE: The purpose of this study was to report a case of acute zonal occult outer retinopathy (AZOOR) with spontaneous remission that was followed up using adaptive optics scanning laser ophthalmoscopy (AO-SLO).

METHODS: The right eye of a 31-year old myopic man diagnosed with AZOOR was followed up. The patient underwent a full ophthalmologic examination, spectral-domain optical coherence tomography (SD-OCT), multifocal electroretinography (mfERG) and imaging with prototype AO-SLO systems (Canon Inc) at the first visit, 1 month after, and 2 months after. Images focused on the photoreceptor layer were recorded in the area, and a montage of AO-SLO images was created.

RESULTS: The patient presented with acute onset of a blind spot and photopsia in his right eye. On AO-SLO, focal dark areas could be observed on the right eye but not on the left eye at the first examination (cone density 8,589/mm(2), mosaic regularity of cone photoreceptors 38.5 %, cone spacing 0.567). The dark areas on AO-SLO corresponded to areas of disrupted inner segments and outer segments (IS/OS) line or ellipsoid of the IS and abnormal area in mfERG. After 1 and 2 months, his symptoms tended to disappear gradually without any treatment. IS/OS line and mfERG could be nearly normalized. Furthermore, normal cone mosaic could be observed in areas where some focal dark spots could be observed at the first examination (cone density 10,112/mm(2), mosaic regularity of cone photoreceptors 39.9 %, cone spacing 0.606).

CONCLUSION: AO-SLO is a useful tool of diagnosis and follow-up of AZOOR. This study might suggest reversible cone damage could occur in some cases of AZOOR with spontaneous remission.