Clinicopathology of non-infectious choroiditis: evolution of its appraisal during the last 2–3 decades from “white dot syndromes” to precise classification

Abstract

Choroidal imaging investigation techniques were very limited until 2–3 decades ago.Fluorescein angiography (FA) was not suited for the analysis of the choroidal compartment and B-scan ultrasonography did not provide enough accuracy. It was on this background that a purely phenomenological approach was attempted to classify these choroiditis diseases by regrouping them under the vague potpourri term of “white dot syndromes”. With the availability of precise investigational modalities of choroidal inflammation or choroiditis-induced lesions, such as indocyanine green angiography (ICGA), spectral domain optical coherence tomography (SD-OCT) and enhanced depth imaging optical coherence tomography (EDI-OCT) it became possible to better classify these diseases based on clinico-pathological mechanisms rather than on purely phenomenological observation.Recently OCT-angiography has implemented the armamentarium of diagnostic techniques possibly also contributing to the classification of choroidal inflammatory diseases.Based on pioneering pragmatism, the aim of this article was to give a clear classification of non-infectious choroiditis. 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.

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

“…Another crucial FA finding is late hyperfluorescence due to pooling. The origin of the fluid is probably a response from the inner retinal vasculature to the outer retina ischemia and is probably associated with the finding of inner retinal vessels dilatation seen on SD-OCT [1,5,61] (Figure 9b).…”

“…The disease is bilateral and limited to one episode. If recurrences occur, the disease should be classified in the mixed intermediary forms [61]. Patients describe a blurry vision with subjective scotomas with or without photopsias.…”

“…Fundus examination reveals posterior pole areas of whitish "placoid" lesions in both eyes. Involvement can be asymmetrical, and there can be a delay from one eye to the other [54,61] (Figure 2). Diagnosis is helped by multimodal imaging and its findings derive from choriocapillary nonperfusion at the base of findings [1,5,8].…”

“…Patients present with photopsias and decreased vision if the lesions are foveal or parafoveal and visual field changes. Fundus examination allows us to distinguish two categories of lesions: (1) punched out small chorioretinal scars in the posterior pole and mid-periphery and sometimes also in the periphery [72] from previous unnoticed episodes and (2) larger faint yellowish-white lesions localized in the posterior pole and mid-periphery resulting from a novel active acute MFC attack [1,5,61,70] (Figure 3).…”

“…Diagnosis is much easier, disease defining features more clearly established, and their monitoring more precise since multimodal imaging is available. During an active phase of the disease, ICGA reveals two types of lesions, (1) small areas remaining hypofluorescent during the whole angiographic sequence (hyperfluorescent on FA) imaging chorioretinal scars of previous episodes and (2) larger hypofluorescent areas from early to late angiographic frames, not visible on FA and delineating new areas of choriocapillaris non-perfusion [1,5,61,68] (Figure 3). FAF is very sensitive in MFC and presents with areas of hyperautofluorescence (active lesions) and hypoautofluorescent spots which correspond to the atrophic scars of previous episodes.…”