Diagnosis and Treatment of Primary Inflammatory Choriocapillaropathies (PICCPs): A Comprehensive Overview

Abstract

Purpose: Primary inflammatory choriocapillaropathies (PICCPs) belong to a group of intraocular inflammatory diseases with the common characteristic of inflammatory choriocapillaris hypo- or non-perfusion as the main clinicopathological mechanism. The purpose of our article is to describe clinical characteristics and multimodal imaging, that can help the diagnosis and treatment of PICCPs. Methods: Narrative review with multimodal imaging analysis. Results: Choriocapillaris non-perfusion can affect the end-choriocappilaries, at the benign end of the PICCP spectrum (MEWDS), to larger choriocapillaris vessels or precapillary vessels at the origin of more severe forms such as acute posterior multifocal placoid pigment epitheliopathy (APMPPE), idiopathic multifocal choroiditis (MFC) and Serpiginous Choroiditis (SC). Diagnosis is mostly based on multimodal imaging and especially on indocyanine green angiography (ICGA), fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (SD-OCT)/OCT-angiography (OCT-A). ICGA shows the typical pattern of patchy lobular hypofluorescence reflecting hypo- or non-perfusion of the choriocapillaris that can also take the aspect of geographic areas in the more severe forms. Treatment depends on the severity of the disease and goes from observation in MEWDS and some mild cases of APMPPE, to oral corticosteroid and/or immunomodulator agents in the more severe conditions of APMPPE and MFC and SC cases. Close multimodal monitoring is crucial in order to introduce or adjust treatment. Conclusion: PICCPs are resulting from one common clinicopathological mechanism, inflammatory choriocapillaris hypo- or non-perfusion. ICGA findings are essential for the diagnosis and follow-up of PICCPs, but non-invasive methods such as FAF and SD-OCT/OCT-A also have their role especially in follow-up of the diseases. Treatment should be individualized according to the pathology and the evolution of lesions.

Diagnosis, Mechanisms, and Differentiation of Inflammatory Diseases of the Outer Retina: Photoreceptoritis versus Choriocapillaritis; A Multimodal Imaging Perspective

“…The choriocapillaritis entities have been well-defined, although some divergent views still exist as far as MEWDS is concerned [ 4 , 14 , 15 , 16 , 17 , 18 ]. These disorders are generated by choriocapillaris non-perfusion of diverse severity and extension depending on the size of the choriocapillaris vessels involved in the process [ 4 ].…”

“…The choriocapillaritis entities have been well-defined, although some divergent views still exist as far as MEWDS is concerned [ 4 , 14 , 15 , 16 , 17 , 18 ]. These disorders are generated by choriocapillaris non-perfusion of diverse severity and extension depending on the size of the choriocapillaris vessels involved in the process [ 4 ]. For MEWDS, small end-capillary low-flow vessels are involved, not detected by OCT-A, except for more pronounced cases that can produce choriocapillary drop-out [ 19 ].…”

“…Among choriocapillaritis entities, multiple evanescent white dot syndrome (MEWDS) and idiopathic multifocal choroiditis (MFC) have a similar, moderately severe involvement of the choriocapillaris; this is quite homogenous between cases, and the pathophysiology can therefore be analysed comprehensively. MEWDS produces less ischaemia as it results from end-choriocapillary closure and as a result, photoreceptors recover faster, whereas in MFC the vessel closure is more proximal, and choriocapillary non-perfusion areas are slightly larger and can produce chorioretinal scars due to RPE damage [ 4 ]. Other choriocapillaritis entities such as acute posterior multifocal placoid pigment epitheliopathy/acute multifocal choriocapillaritis (APMPPE/AMIC), because of the great variability and diverse severity from one case to another, are less suited to determine the nature of events of the lesion processes by multimodal imaging.…”

Benefits and Limitations of OCT-A in the Diagnosis and Follow-Up of Posterior Intraocular Inflammation in Current Clinical Practice: A Valuable Tool or a Deceiver?

“…The OCT-A findings within the 6 × 6 mm window analyzed correlate well with the hypofluorescent zones demonstrated by ICGA. Furthermore, outer retinal alterations on SD-OCT co-localize with the zones of choriocapillaris drop-out on OCT-A [ 28 , 29 ]. OCT-A is useful as part of the multimodal imaging in the follow-up of APMPPE within its limited field of view and can play a more important monitoring role because it can be repeated easily as it is non-invasive.…”

“…Both conditions will be discussed together. ICGA has been shown to be the most reliable imaging modality to globally identify the extent of lesions and monitor the evolution of the disease and the response to therapy [ 28 ]. OCT-A was shown to supplement other imaging techniques, such as ICGA and EDI-OCT [ 30 ].…”