Epiretinal Neovascularization: A Novel OCT Angiography Finding in Macular Telangiectasia Type 2

Purpose: To report a novel finding of epiretinal neovascularization (ERN) in cases of macular telangiectasia (MacTel) type 2 and describe its clinical and multimodal imaging features.

Design: Retrospective chart review.

Participants: Patients attending the retina clinic from January 2017 through April 2018. Those diagnosed with MacTel by clinical and imaging findings were included.

Methods: Best-corrected visual acuity in logarithm of minimum angle of resolution units, anterior segment examination, slit-lamp biomicroscopy, fundus photography, spectral-domain OCT, autofluorescence imaging, fundus fluorescein angiography, and OCT angiography (OCTA) were performed in all MacTel patients. Length of ellipsoid zone disruption, external limiting membrane disruption, area of the ERN in square millimeters, and central macular thickness in micrometers were noted.

Main outcome measures: The finding of an epiretinal membrane on spectral-domain OCT and a corresponding well-defined vascular complex on the vitreoretinal interface on OCTA in MacTel patients was considered to be evidence of epiretinal neovascular membrane (ERNM).

Results: Sixty-eight MacTel eyes underwent multimodal imaging, of which 7 eyes of 4 patients were identified as having ERN or ERNM. The ratio of men to women was 1:1 (n = 4); 1 patient had unilateral disease and 3 patients had bilateral disease. Mean age was 56.75 ± 10.71 years. Mean best-corrected visual acuity was 0.74 ± 0.39 logarithm of the minimum angle of resolution. Retinal pigment and dipping venules were present in 100% of eyes. Diffuse thinning and collapse sign were seen in all eyes. OCT angiography revealed a vascular membrane owing to the ERNM at the vitreoretinal interface. Mean area of the ERNM was 0.44 ± 0.248 mm². This vascular membrane showed a demonstrable communication with the intraretinal abnormal vascular plexus in 6 of 7 eyes. None of the eyes showed a choroidal neovascular membrane.

Conclusions: Epiretinal neovascularization is a novel finding in MacTel type 2. These neovascular membranes are visualized best using OCT and OCTA. They are associated with retinal pigment and diffuse retinal thinning. Histopathologic studies are needed to characterize these membranes further.