Analiza i povezanost vaskularnih i strukturnih promena retine kod pacijenata sa primarnim glaukomom otvorenog ugla

Abstract

Glaucoma is a heterogeneous group of optic neuropathies with progressive loss of retinal ganglion cells (RGC), characterized with changes in the optic nerve head (ONH) and retinal nerve fibers (RNFL), consequently damaging the visual field. The aim of this study was to analyze the vascular and structural changes of the retina and determine their correlations in patients with different stages of primary open-angle glaucoma and the healthy population. This research is a prospective clinical study conducted on 196 adults examined at the Clinic for Ophthalmology Clinical Center of Nis. All subjects were classified into four groups: Group 1 – healthy patients, Group 2 – patients with first stadium of POAG, Group 3 – patients with second stadium of POAG and Group 4 – patients with the third stadium of POAG. All subjects underwent the standard ophthalmologic examination. Structural and vascular changes of the retina were analyzed using optical coherence tomography (OCT) and angiography (OCTA) on the Optovue device, the AngioVue Comprehensive Imaging system in different stages of glaucoma. OCT measured the thickness of RNFL, RNFL_sup and RNFL_inf; GCC, GCC_sup and GCC_inf. OCTA analyzed the vessel capillary density (VCD) and vessel density (VD) at the ONH level: whole image-wiVCD/VD, inside disc-idVCD/VD, peripapillary-ppVCD/VD, ppVCD_sup, and ppVCD_inf; foveal avascular zone (FAZ area and perimeter), foveal density (FD); as well as the macular vessel density (VD) in the superficial (VD SL) and deep (VD DL) retinal vascular plexus. Results of the OCT analysis showed that the average thickness of RNFL and the thickness of GCC was reduced in POAG eyes in comparison to healthy eyes, especially in cases of increased POAG severity. OCTA analysis found that VCD values in ONH, FD and VD macula also decreased with POAG progression, showing the lowest value in patients with advanced glaucoma. FAZ parameters (area and volume) were higher in POAG patients, especially in the later stages of the disease. In patients with POAG, there is a significant correlation between the structural and vascular changes, observed between RNFL thickness with VCD and VD at the ONH level, as well as GCC with VD in all layers and segments of the macula, with this correlation being stronger with disease progression. Significant vascular and structural changes of the retina at the level of ONH and macula were detected and their interrelationship in patients with POAG, using OCT and OCTA. Analysis of OCT and OCTA parameters can serve for noninvasive quantification of structural and vascular changes at the level of the optic nerve head and macula, showing a significant correlation with the presence and progression of POAG.