Acute Zonal Occult Outer Retinopathy; Revisited

Multicolor imaging: Current clinical applications

Multicolor (MC) imaging is an innovative pseudocolor fundus imaging modality based on confocal scanning laser ophthalmoscopy. It effectively scans the retina at different depths to create a composite image. The green reflectance image depicts the middle retinal while blue reflectance image provides images of the retinal surface. The infrared reflectance image depicts retinal structures at the level of outer retina and choroid. We systematically analyze published case reports, case series, and original articles on MC imaging where it has helped in discovering additional clinical features of retinal diseases not readily apparent on conventional color fundus photography and played a role in monitoring the response to treatment.

Acute Zonal Occult Outer Retinopathy in a Patient Suffering from Epilepsy: Five-Year Follow-Up

We report an unprecedented case of a young patient with epilepsy coexisting with acute zonal occult outer retinopathy (AZOOR), a rare white dot syndrome of unknown etiology, associated with damage to the large zones of the outer retina. Recently, it has been established that epileptic episodes contribute to an inflammatory response both in the brain and the retina. A 13-year-old male patient with epilepsy was referred by a neurologist for an ophthalmologic consultation due to a sudden deterioration of visual acuity in the left eye. The examination, with a key role of multimodal imaging including color fundus photography, fluorescein angiography, indocyanine green angiography (ICGA), fundus autofluorescence (FAF), swept-source optical coherence tomography (SS-OCT) with visual field assessment, and electroretinography indicated AZOOR as the underlying entity. Findings at the first admission included enlargement of the blind spot in visual field examination along a typical trizonal pattern, which was revealed by FAF, ICGA, and SS-OCT in the left eye. The right eye exhibited no abnormalities. Seminal follow-up revealed no changes in best corrected visual acuity, and multimodal imaging findings remain unaltered. Thus, no medical intervention is required. Our case and recent laboratory findings suggest a causative link between epilepsy and retinal disorders, although this issue requires further research.

Two case reports of acute zonal occult outer retinopathy (AZOOR): Importance of multimodal diagnosis

A presentation is made of two cases of acute zonal occult outer retinopathy (AZOOR); one a young man of 19 years, and the other a 42-year-old woman. The young man complained of unilateral scotoma and photopsia. The woman presented with bilateral visual loss and photopsia. Multimodal imaging, including fundus photography, fluorescein angiography, fundus autofluorescence, spectral-domain optical coherence tomography, and visual field testing, supported the diagnosis of AZOOR. The differential diagnosis is complicated, since it has clinical features in common with other retinopathies. This means that it is essential to use modern imaging tests, especially those where the characteristic trizonal pattern is shown, such as in autofluorescence and OCT.

The role of optical coherence tomography in the diagnosis of afferent visual pathway problems: A neuroophthalmic perspective

Optical coherence tomography (OCT) is a noninvasive ocular imaging technique that has become a standard tool in neuroophthalmic practice. Specifically, OCT captures retinal manifestations of neuroaxonal injury caused by lesions along anterior and posterior regions of the afferent visual pathway, in patients presenting with vision loss. More recently, the advent of OCT angiography (OCTA) has enabled evaluation of the choroidal and retinal microvasculature, thus informing our understanding regarding vascular mechanisms associated with optic nerve and retinal injuries. Much of our longitudinal experience with OCT in the field of neuroophthalmology has been acquired from the study of optic neuritis (ON) caused by inflammatory disorders of the central nervous system (CNS). Over the past two decades, OCT has emerged as a surrogate endpoint for CNS neuroaxonal injury in multiple sclerosis (MS) research trials. On a more pragmatic level, OCT is used in the clinical arena to diagnose ON associated with: MS, neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein (MOG) antibody associated disease (MOGAD). Subsequent advancements in swept-source (SS) and enhanced depth imaging (EDI) have established OCT as the new "gold standard" in the diagnosis of optic disc drusen. Recent studies have highlighted pathognomonic OCT features that distinguish cases of true papilledema from pseudopapilledema, in patients presenting with undifferentiated optic disc elevation. Preoperative OCT measures of neuroaxonal integrity have shown prognostic value in predicting postoperative visual outcomes for patients with compressive anterior visual pathway lesions. Finally, OCT is indispensable in differentiating optic neuropathies from retinal diseases in patients with visual loss and a nondiagnostic fundus examination. An in-depth discussion regarding the technical aspects of OCT is beyond the scope of this chapter. Instead, we wish to highlight the value OCT brings to the diagnosis and management of common neuroophthalmic conditions, with emphasis on optic neuropathies and retinal disorders.

Long term follow-up and effect of immunosuppression in acute zonal occult outer retinopathy

Acute zonal occult outer retinopathy (AZOOR) is a rare syndrome characterized by sudden onset of photopsia, scotomas, and abnormal electrophysiological tests, predominantly affecting young women. Although its pathogenesis remains unknown, auto-reactivity to retinal components is thought to mediate tissue damage. A 42-year-old woman presented with symptoms and examination consistent with the diagnosis of AZOOR. She was treated with azathioprine for 5 years. In spite of the immunosuppressive treatment, clear progression in the visual field, autofluorescence, electrophysiological tests and optical coherence tomography was observed. Treatment with intravenous immunoglobulins (IVIg) and subcutaneous Abatacept was subsequently started with little efficacy. Hereby, we present a case of progressive AZOOR despite aggressive immunosuppression with 10-year follow up. Currently, there is no consensus regarding management of AZOOR, and the convenience of administering aggressive immunosuppression remains uncertain.