Epiretinal membrane formation and optic disc vascularisation in type 2A macular telangiectasia (MacTel)

To describe a rare clinical finding of epiretinal membrane (ERM) and abnormal optic disc vascularisation in type 2A macular telangiectasia (MacTel).

A 52-year-old asymptomatic healthy male was examined in the retina clinic. In both eyes, corrected visual acuity was 20/20, N6. Anterior segment examination and intraocular pressure were both normal in both eyes.

The right eye's dilated fundus examination revealed loss of retinal transparency and superficial intraretinal crystals. A thick ERM extending from the optic disc to the macula obscured the details of the underlying perifoveal region in the left eye fundus. The diagnosis of bilateral type 2 MacTel was confirmed by confocal blue reflectance imaging, fluorescein angiography (FA), and macular optical coherence tomography (OCT). The left eye macular OCT scan also revealed a thick ERM without causing significant retinal traction. Furthermore, FA of the left eye revealed early hyperfluorescence with intense late leakage at the inferior aspect of the optic disc, giving the impression of abnormal optic disc vascularisation. No other cause for the disc vascularisation could be identified. OCT scan through the area with the optic disc leakage revealed a tuft of irregular hyperreflective tissue lying over the ERM. OCT angiography imaging confirmed the vascularity within the tuft of hyperreflective tissue over the ERM. Over a two-year period, no changes in clinical or imaging features were observed.

In type 2A MacTel eyes, ERM formation and abnormal disc vascularisation are uncommon findings. More histopathologic research is needed to characterise these membranes.