MULTIZONAL OUTER RETINOPATHY AND RETINAL PIGMENT EPITHELIOPATHY (MORR): A Newly Recognized Entity or an Unusual Variant of AZOOR?

PURPOSE: To describe specific clinical, multimodal imaging, and natural history features of an unusual variant of acute zonal occult outer retinopathy. METHODS: Retrospective, observational, longitudinal, multicenter case series. Patients exhibiting this unusual clinical condition among cases previously diagnosed with acute zonal occult outer retinopathy were included. Multimodal imaging, laboratory evaluations, and genetic testing for inherited retinal diseases were reviewed. RESULTS: Twenty eyes from 10 patients (8 females and 2 males) with a mean age of 54.1 ± 13.3 years (range, 38–71 years) were included. The mean follow-up duration was 13.1 ± 5.3 years (range, 8–23 years). Presenting symptoms were bilateral in 7 patients (85% of eyes) and included scotomata and photopsia. All patients had bilateral lesions at presentation involving the peripapillary and far peripheral retina. Baseline optical coherence tomography showed alteration of the retinal pigment epithelium and photoreceptor layers corresponding to zonal areas of fundus autofluorescence abnormalities. Centrifugal and centripetal progression of the peripapillary and far-peripheral lesions, respectively, occurred over the follow-up, resulting in areas of complete outer retinal and retinal pigment epithelium atrophy. CONCLUSION: Initial alteration of photoreceptors and retinal pigment epithelium and a stereotypical natural course that includes involvement of the far retinal periphery, characterize this unusual condition. It may represent a variant of acute zonal occult outer retinopathy or may be a new entity. We suggest to call it multizonal outer retinopathy and retinal pigment epitheliopathy.