Papillary optical coherence tomography angiography in optic neuropathies.

Aim: to describe and analyze peripapillary microvascular changes in eyes with optic neuropathies using optical coherence tomography angiography (OCTA).
Methods: In this cross-sectional observational study, 63 eyes of 48 patients with different causes of optic neuropathy and 36 healthy control eyes were evaluated by optical coherence tomography (OCT) and OCTA (Topcon DRI OCT; Triton) between January 2018 and December 2018 at the Fattouma Bourguiba ophthalmology department in Monastir.
Results: Vascular changes were more frequent in acute non arteritic anterior ischemic optic neuropathy (NAION) than in optic neuritis. Eyes with optic atrophy had capillary rarefaction corresponding to the area of thinning of the peripapillary optic fiber layer (RNFL). The peripapillary vascular density (PVD) was lower (p=0.036) in case of optic atrophy compared to normal eyes. For non arteritic ischemic optic neuropathy and for chronic retrobulbar optic neuritis (NORB), a positive correlation between visual acuity and PVD was observed (p<0.05). An inversely proportional correlation between the PVD and the duration of evolution was noted. In the multivariate study, high blood pressure was a systemic factor correlated with peripapillary microvascular damages.
Conclusion: OCTA showed a reduction in PVD and greater vascular changes in acute non-arteritic ischemic optic neuropathy than in edematous optic neuritis. At the atrophic stage, the PVD was reduced. Hypertension was an independent factor correlated with peripapillary microvascular damages.