Distinctive mechanisms and patterns of exudative versus tractional intraretinal cystoid spaces as seen with multimodal imaging.

Abstract

Purpose : To determine clear-cut distinctions between tractional and exudative intraretinal cystoid spaces subtypes.

Methods : A cohort of patients diagnosed with intraretinal cystoid spaces and imaged with optical coherence tomography (OCT), fluorescein angiography (FA), blue fundus autofluorescence (BFAF), en-face OCT and OCT-angiography (OCT-A) was included in the study. All images were qualitatively and quantitatively evaluated (Figure 1).

Results : In this study were included 72 eyes of 69 patients. Exudative intraretinal cystoid spaces (36/72 eyes, 50%), displayed a “petaloid” morphology as seen with en-face OCT, FA and BFAF. Tractional intraretinal cystoid spaces (24/72 eyes, 33.3%), displayed a radial “spoke- wheel” en-face OCT pattern). There was no leakage with FA and BFAF did not reveal specific patterns. Eyes with full-thickness macular hole (FTMH, 12/72 eyes, 16.7%) displayed a “sunflower” en-face OCT appearance. FTMH showed OCT, OCT-A and BFAF features of both exudative and tractional cystoid spaces, but without any FA leakage. INL thickness was significantly lower in tractional cystoid spaces (p<0.001). There were a greater number of INL cystoid spaces in both the exudative and FTMH subgroups (p=0.001). The surface area of INL cystoid spaces was significantly lower in the tractional subgroup (p<0.001). There was a significant reduction of the microvascular density in eyes with exudative versus tractional (p=0.002) and FTMH (p<0.001) subgroups.

Conclusions : Exudative and tractional intraretinal cystoid spaces displayed characteristic multimodal imaging features and they may represent two different pathologic conditions with equally different clinical implications, as illustrated in Figure 2.

This is a 2020 ARVO Annual Meeting abstract.

 

Figure 1. En-face OCT analysis.
A. En-face 3x3mm segmented at the outer retina in Irvine-Gass syndrome, tractional lamellar macular hole and full-thickness macular hole. B. Automated thresholded image. C. Automated binarization. D. Automated quantitative analysis. E. Intraretinal cystoid spaces patterns.

 

Figure 2: Pathophysiological differences between cystoid spaces.
A, B. Exudative: the increase in capillary permeability and fluid expansion displace Müller cells and the surrounding architecture. C,D. Tractional: traction creates anatomical spaces filled with interstitial fluid. E. Full-thickness macular hole: the retina is hydrated at the edge of the hole.