OCT of Outer Retinal Hyperreflectivity, Neovascularization, and Pigment in Macular Telangiectasia Type 2.

Purpose: To investigate whether outer retina hyperreflectivity (ORHR) and outer retina neovascularization (ORNV) are visible in eyes with macular telangiectasia type 2 (MacTel 2) before pigment proliferation is visible.

Design: Retrospective study in a cohort of patients from the MacTel Project.

Participants: Thirty-nine MacTel 2 eyes without pigment on color fundus photography (CFP) at presentation were studied over a mean of 36.6 months (range, 13.8-50.4 months; standard deviation, ±10 months).

Methods: All patients routinely underwent Snellen best-corrected visual acuity (VA) measurement, CFP, spectral-domain OCT, and OCT angiography (OCTA).

Main Outcome Measures: Pigment in the macula on CFP, best-corrected VA, presence of ORHR, presence of ORNV, presence and surface of ellipsoid zone (EZ) loss, and occurrence of ORHR, ORNV, and pigment.

Results: At presentation, 13 eyes showed no EZ loss, and no ORHR nor change was observed during the follow-up. In the 19 eyes with only EZ loss at baseline, ORHR appeared in 6 eyes, and one of them also showed visible pigment on CFP. Among the 7 eyes with ORHR and ORNV at baseline, pigment proliferation became visible in 4 eyes. Overall, at the end of follow-up, 14 eyes showed ORNV and 13 showed ORHR, of which 5 showed pigment on CFP. In all cases, ORHR on spectral-domain OCT corresponded to ORNV on OCTA. Hyperreflectivity and neovascularization developed within an EZ loss area or at its edge. At the end of follow-up, although the EZ loss area was larger in eyes with ORHR, pigment, or both than in eyes without any pigment migration (0.33 mm vs. 0.94 mm; P = 0.01), VA was similar in both groups (0.32 logarithm of the minimum angle of resolution [logMAR] vs. 0.35 logMAR; Snellen equivalent, 20/40 vs. 20/50; P = 0.64).

Conclusions: Spectral-domain OCT and OCTA showed that in MacTel 2 eyes, ORHR was associated with ORNV on OCTA and most often did not correspond to pigmentation on CFP. When ORNV developed, hyperreflectivity appeared along the abnormal capillary tracts after a mean follow-up of 36 months. In most cases, the presence of ORHR was not associated with rapid vision loss.