The Imaging Correlation between outer retina-associated hyperreflectivity and outer retinal and choroidal microvascular changes in Macular Telangiectasia type 2.

PURPOSE: To elucidate outer-retinal choroidal microvascular abnormalities (ORCMA) observed in Macular Telangiectasia type 2 (MacTel 2), particularly in association with outer retina-associated hyperreflectivity (ORaH).

METHODS

Retrospective analysis of 60 eyes with MacTel 2 having ORaH was conducted. OCT and OCTA images were meticulously reviewed to identify ORCMA patterns.

RESULTS

All 60 eyes exhibited hyperreflective foci (HRF), with varying incidences of subsidence, ellipsoid zone (EZ) loss, pigment clumps, cystoids, and double-layer sign (DLS). Vascular invasion, retinochoroidal anastomosis (RCA), and macular neovascularization (MNV) were observed, with all cases demonstrating ORaH. OCTA revealed microvascular changes. Subsidence correlated significantly with invasion (P=0.009), while pigment clumps, cystoids, and DLS were not significant. RCA was associated with pigment clumps, cystoids, and DLS (P<0.05), whereas MNV correlated with subsidence (P=0.022).

CONCLUSION

The study delineates ORCMA in MacTel 2, identifying three patterns: vascular invasion, RCA, and MNV. Vascular invasion affects the outer retina, potentially leading to subsidence. RCA, a pre-proliferative stage, involves anastomosis between retinal and choroidal microvasculature, associated with pigment clumps, cystoids, and DLS. MNV, an advanced stage, exhibits extensions below the RPE and exudation, suggesting a continuum from invasion to neovascularization. Recognizing these stages aids in diagnosis, prognosis, and intervention development for MacTel 2.