Intraretinal Fibrosis in Macular Telangiectasia Type-2 (MacTel): Clinical and Multimodal Imaging Features.

Objective: To explore the clinical and multimodal imaging characteristics of Intraretinal Fibrosis (IRFib) in Macular Telangiectasia Type-2 (MacTel).

Methods: MacTel eyes with IRFib that had multimodal imaging with color fundus photography, multicolor (MC), blue reflectance, spectral-domain optical coherence tomography (OCT), OCT-angiography (OCTA) and fluorescein angiography.

Results: Seven eyes of 6 patients were included. Clinically, all cases had grayish-white fibrosis at macula, with retinal vessel tortuosity in two cases best characterized on MC. Two eyes each belonged to Gass and Blodi stages 3 and 4, three eyes were stage 5 MacTel. The mean lesion area at presentation was 1.36 ± 0.81 mm2 (range 0.56-2.99 mm2). The defining OCT finding for IRFib was hyper-reflective distortion intraretinally (involving different layers). Other accompanying findings in decreasing order were collapse sign (7 eyes); epiretinal membrane (6 eyes); pigment clumping and migration (5 eyes); serrated internal limiting membrane and outer-retinal hyper-reflectivity (4 eyes); and lamellar macular hole (1 eye). On OCTA, IRFib was associated with right-angled vessels, vascular invasion and distortion of foveal avascular zone (FAZ), and vessel dilatation and tortuosity in superficial vascular complex; telangiectasia, FAZ distortion and invasion, vessel drag, capillary looping, and abnormal vascular structures in deep capillary plexus; and nodular tuft or twig-like hyper-reflective vascular lesions in outer-retina choriocapillaris slab.

Conclusions: The incidence of IRFib on MC in our MacTel cohort was 1.75% with characteristic findings on OCT and OCTA. They are associated with advanced MacTel and probably implicate Müller cell dysfunction, activated glial cells, and vascular changes during the disease process.