Analysis of changes in structural and hemodynamic parameters of the retina and foveolar avascular zone in patients with primary open-angle glaucoma and diabetes mellitus observed in long-term follow-up

Abstract

PURPOSE. To study the changes in structural and hemodynamic parameters of the retina and foveolar avascular zone (FAZ) over time in patients with primary open-angle glaucoma (POAG) and diabetes mellitus (DM) observed in long-term follow-up.MATERIALS AND METHODS. The study included 258 patients (258 eyes) divided into five groups: group 1 — 58 patients (58 eyes) with stage I POAG and DM; group 2 — 50 patients (50 eyes) with stage I POAG; group 3 — 50 patients (50 eyes) with stage III POAG and DM; group 4 — 50 patients (50 eyes) with stage III POAG; group 5 — 50 patients (50 eyes) with DM. Patients underwent comprehensive ophthalmological examination, spectral domain optical coherence tomography (SD-OCT), optical coherence tomo-graphy angiography (OCT-A) of the macular region. The follow-up lasted 24 months.RESULTS. Analysis of the initial parameters in groups of patients with comorbidities showed the lowest values compared to controls, which were progressively worsening. MD in the group with DM + stage I POAG had reliably decreased after 12 months (by 5.05%), after 24 months by 12.12% (p≤0.05). The speed of GCL+IPL loss in groups 1 and 3 during the first year of observation was almost equal for initial and advanced glaucoma — 1.35 (-2.03%) and 1.32 (-2.36%) µm/year, but in group 3 the loss had doubled after two years (2.48 (-4.44%) and 1.41 (2.12%) µm/year). Deterioration of hymodynamic parameters in the macular region in groups 1 and 3 was noted primarily in the inner sectors (whole image vessel density in parafovea (PF wiVD) -0.79% during the first, and -2.57% during the second year in initial glaucoma, -0.6% and -1.24% in advanced, whole image vessel density in parafovea (PF wiVD) -0.2% and -1.22%, -0.66% and -1.56%, respectively). Parameters of FAZ had changed significantly after 2 years in patients with stage I POAG and DM: its area size had increased by 10.2%, perimeter by 4.49%, circularity index had decreased by 3.17%.CONCLUSION. Comorbidity of POAG and DM is accompanied by development and quick progression of significant changes in structural and hemodynamic parameters of the retina as observed by this long-term follow-up.