Blood Flow Velocity and Foveal Thickness in the Macula Before and After Vitreous Surgery for Epiretinal Membrane

Abstract

Purpose: : To compare blood flow velocity (BFV) in the perifoveal capillaries and foveal thickness (FT) before and after vitreous surgery for epiretinal membrane.

Methods: : Ten eyes with epiretinal membrane (Group E) and 16 eyes with normal subjects (Group N) were involved in this study. Fluorescein angiography(FA) was performed using scanning laser ophthalmoscope (SLO) and analyzed BFV by the tracing method. FT was measured by optical coherence tomography (OCT).

Results: : BFV was significantly slower in Group E before the surgery(1.05 ± 0.08 mm/sec) compared with the patients in Group N (1.49 ± 0.11 mm/sec ) (p<0.0001). BFV was significantly increased in Group E (1.30 ± 0.10 mm/sec) (p =0.0006) at 6 months after surgery. FT was significantly greater in Group E (316.2 ± 105.2 µm) compared with Group N (158.9 ± 16.9 µm)(p =0.0011). FT was significantly decreased in Group E (256.0 ± 64.1 µm)(p =0.0061) at 6 months after surgery. No significant correlation was found between BFV and FT before the surgery. On FA, Group E showed morphological abnormalities of the macular vessels, such as tortuous capillaries, occlusion, capillary aneurysms, and loop formation.

Conclusions: : In eyes with ERM, BFV was slower , and improved significantly after vitreous surgery. We conclude that BFV is decreased due to abnormalities of the capillaries caused by traction on the retinal vessels associated with contraction of the epiretinal membrane.

Keywords: macula/fovea • vitreoretinal surgery