Classification of Non-Infectious and/or Immune Mediated Choroiditis: A Brief Overview of the Essentials

Abstract

The choroid was poorly accessible to imaging investigation until the last decade of the last century. With the availability of more precise imaging methods such as indocyanine green angiography (ICGA) and, later, optical coherence tomography (OCT), enhanced depth OCT (EDI-OCT), and OCT angiography (OCTA), appraisal of choroidal inflammation has substantially gained in accuracy. This allowed to precisely determine which structures were touched in the different non-infectious choroiditis entities and made it possible to classify this group of diseases, ICGA signs, mainly hypofluorescent lesions, were identified and described. Previous publications have divided angiographic findings into two main sets of signs: (1) irregular “geographic” hypofluorescent areas corresponding to choriocapillaris non-perfusion and (2) round more regular, hypofluorescent dark dots more evenly distributed in the fundus corresponding to more deep choroidal stromal foci. These distinct findings allowed to subdivide and classify choroiditis into choriocapillaritis and stromal choroiditis. Additional signs were identified from EDI-OCT and OCTA examination supporting the classification of choroiditis into choriocapillaritis and stromal choroiditis. Results: Diseases involving principally the choriocapillaris included Multiple Evanescent White Dot Syndrome (MEWDS), Acute Posterior Multifocal Placoid Pigment Epitheliopathy (APMPPE), Idiopathic Multifocal Choroiditis (MFC), and Serpiginous Choroiditis (SC) as well as mixed forms. Diseases primarily involving the choroidal stroma included HLA-A29 Birdshot Retinochoroiditis (BRC), Vogt-Koyanagi-Harada disease (VKH), Sympathetic Ophthalmia (SO), and Sarcoidosis chorioretinitis (SARC). Thanks to new imaging investigations of the choroid, it is now possible to classify and understand the diverse clinicopathological mechanisms in the group of non-infectious choroiditis entities.

Reactivation of Vogt-Koyanagi-Harada disease under control for more than 6 years, following anti-SARS-CoV-2 vaccination

“…Vogt-Koyanagi-Harada (VKH) disease is a primary stromal choroiditis [ 1 , 2 ] caused by an autoimmune reaction against melanocyte associated proteins [ 3 , 4 ]. Eye involvement is associated with systemic manifestations including inflammation of the meninges (CSF mononuclear pleiocytosis) and auditory disturbances [ 5 , 6 ].…”

Long-Term Clinical and Multimodal Imaging Findings in Patients with Disseminated Mycobacterium Chimaera Infection

“…Ocular involvement in patients with sarcoidosis is common and has been previously reported in 15–25% of the cases [ 20 ]. The ocular signs seen in sarcoidosis, if choroidal involvement is present, are not specific for sarcoidosis and can also be seen in other granulomatous involvement such as ocular tuberculosis [ 21 ]. Posterior segment involvement occurs in up to one-third of the patients with ocular sarcoidosis, anterior uveitis, vitreous inflammation and cystoid macular edema, and usually leads to blurry vision.…”

“…Despite tuberculostatic therapy, progression of the number and size of choroidal lesions was observed. The ocular lesions reflected systemic disease activity, and ultimately this patient died of splenic rupture and disseminated mycobacterial infection [ 21 ].…”

Acute posterior multifocal placoid pigment epitheliopathy (APMPPE)

“…The late hyperfluorescence is the result of the change in the polarity of the RPE, affected by ischaemia, resulting in a deficit of pumping that interferes with the movement of the fluid from the retina to the choroid. Another hypothesis has been put forward indicating that profound ischaemia of the outer retina could produce reactionary hyperpermeability and exudation from retinal vessels [36,37]. Healed lesions may demonstrate hyper and hypofluorescence throughout the exam, reflecting RPE disturbance, namely window defect due to RPE atrophy and pigmentary changes.…”