The role of retinal microcirculation disorders in the progression of glaucomatous optic neuropathy
Purpose - to assess the progression of primary open-angle glaucoma (POAG) and to study the role of retinal microcirculation in its progression. Material and methods. In this 2-year prospective study, the rate of POAG progression was determined using perimetry (ROP1) and spectral domain optical coherence tomography (SD-OCT) by thinning of retinal nerve fiber layer (RNFL) (ROP2) and ganglion cell complex (GCC) (ROP3). The vessel density of parafoveal superficial plexus (VD parafovea) and peripapillary retina (VD ppr) was assessed using OCT angiography, peripheral resistance index (RI), and blood flow velocity in the posterior short ciliary arteries (PSCA) and central retinal artery (CRA) with the use of color Doppler mapping. The predictive properties of each parameter were calculated using the area under receiver operating curve (AUC). Results. Progression was detected in 9.8% cases by perimetry and in 19.7% cases by OCT. The combination of these two methods increased the detection up to 32.8%. Circulatory parameters - VD parafovea (AUC 0.70±0.07), VD ppr (0.715±0.07), PSCA RI (0.801±0.12), CRA RI (0.798±0.11) - had similar high predictive properties as IOP max (0.79±0.05), corneal hysteresis (0.755±0.07), thickness of inner parafoveal layers (0.728±0.07) and RNFL (0.692±0.06). The study revealed the following correlations: ROP1 with maximum IOP (p=0.01), ROP2 with blood flow velocity in PSCA (p=0.01), VD parafovea with corneal hysteresis (p=0.01), and GCC thickness with ocular perfusion pressure (p=0.01). Conclusion. The obtained data demonstrates the importance of combining perimetry with OCT for detecting the progression of glaucoma and indicates its relationship with reduced ocular hemoperfusion.