Evaluation of Retinal Blood Flow in Glaucoma Patients Pre and Post Treatment using OCT angiography

Abstract

Purpose: To evaluate retinal blood flow changes in glaucoma after intraocular pressure (IOP) lowering and to determine whether a correlation exists with retinal capillaries blood flow with IOP changes using optical coherence tomography angiography (OCTA)

Materials and Methods: OCTA images were collected from 24 glaucomatous eyes for the macula and 21 eyes for the optic disc in a prospective, cross-sectional observational study. Microvascular changes were analysed at two retinal layers: deep vascular plexus (DVP) and the superficial vascular plexus (SVP) as well as choriocapillaries (CC), were compared pre and six weeks post intraocular pressure (IOP) lowering treatment.

Results: Retinal blood flow across the macula showed no statistical significance at: SVP (z-score = -0.887), DVP (z-score = -1.093) and CC (z-score = -1.423). Further, no statistically significant difference in retinal blood flow was observed across the disc: SVP (z-score = -0.918), DVP (z-score = -1.057) and CC (z-score = -0.295). While the IOP showed improvement (z-score = -5.049), visual acuity deteriorated (z-score= 1.686)

Conclusion: No statistical difference was found in the data for all layers of both the areas surrounding the disc and macula at 6 weeks. OCTA can detect microstructural defects and future longitudinal studies may provide further insight into effects of IOP lowering treatment on retinal blood flow in glaucoma patients in longer term.