Differences in structural optical coherence tomography and infrared enface images between non-exudative macular neovascularizations secondary to AMD and pachychoroid disease

Purpose: To provide an analysis of structural optical coherence tomography (OCT) and enface infrared reflectance (IR) differences between non-exudative macular neovascularizations (NE MNVs) secondary to age-related macular degeneration (AMD) and NE MNVs secondary to pachychoroid spectrum. Methods: Patients diagnosed with NE-MNV documented by OCTA and dye angiography in the context of either AMD or pachychoroid spectrum were retrospectively included in AMD group and PACHY group respectively. Only treatment-naïve NE MNVs showing persistence of non-exudative status for at least 1 year after diagnosis were considered. Availability of good quality structural OCT B scan and IR enface acquisitions both at baseline and at 1 year follow up was also required. Results: The study population included 15 eyes of 15 patients in AMD group and 13 eyes of 13 patients in PACHY group. AMD group showed at baseline a significantly wider pigment epithelium detachment (PED) apex angle (p = 0.02), higher homogeneity of the PED (p = 0.015), higher PED shadowing(p = 0.03). Both groups experienced a widening of apex angle (flattening of the PED) during follow-up. Ten (76.9%) patients in PACHY group showed a hyporeflective halo at the margins of the PED at baseline compared to 3/15 (20.0%) patients in AMD group (0.007), with no significant changes at 1 year follow up (p = 0.47). Conclusion: NE-MNVs in pachychoroid eyes are characterized by sharper and more inhomogeneous PEDs with a lighter choroidal shadowing compared to NE-MNVs in AMD eyes. Moreover, they often show a hyporeflective halo around the lesion with IR imaging.