Macular and peripapillary microvascular changes in open angle glaucoma and ocular hypertension: A longitudinal study using optical coherence tomography angiography (OCT‐A)

Abstract

Purpose: To investigate prospectively macular and peripapillary microvascular changes in patients with glaucoma and ocular hypertension. Methods: A 12‐month prospective longitudinal study was performed with 124 open‐angle‐glaucoma‐eyes (GE), 111 ocular‐hypertension‐eyes (OHE) and 98 gender and age matched control‐eyes (CE). Glaucomatous progression was defined as a decrease of ≥5 μm in average or ≥7 μm in a sector of RNFL thickness. OMAG OCT microangiography (Angioplex, HD OCT, Cirrus 5000, Zeiss) was used to analyse optic disc and macular regions. The statistical analysis was performed using Mann–Whitney‐Test with the SPSS version 23.0 statistical package (SPSS Inc., IL). Results: Among OHE and GE groups, 21.7% of eyes showed progression, being the decrease of Peripapillary Flux Index (PFI), Macular Vessel Density (MVD) and Macular Capillary Perfusion Density (MPD) greater (−0.0067; −0.696 mm/mm2 and −1.56%) compared to non‐progressive eyes (+0.0038; 0.527 mm/mm2 and 1.55%) being the nasal and inferior sectors for PFI, and the superior and temporal sectors for both MVD and MPD, the ones that showed greater differences [p = 0.015 and p < 0.001 for the last two]. Furthermore, Peripapillary Perfusion Density (PPD) showed non‐significant greater decrease (−0.347) compared to non‐progressive eyes (−0.324) [p = 0.775]. Characteristics as increased vertical cup to disc ratio (CDV) (0.64 vs. 0.57), elevated intraocular pressure (IOP) (18.25 vs. 15.40 mmHg), thinner central corneal thickness (CCT) (520.18 vs. 541.67 μm) and lower ocular perfusion pressure (OPP) (47.81 vs. 48.95 mmHg) were significantly different in those progressive OHE and GE [p < 0.05 for all]. Nevertheless, minimum ganglion cell layer thickness (GCLM) was only significantly lower in progressive GE (58.51 vs. 73.98 μm) [p = 0.036]. Conclusions: Data showed that when glaucomatous progression took place, stronger microvascular changes occurred in the macular and peripapillary areas, as greater decrease of MVD, MPD and PFI, especially in superior and temporal sectors for the macular area, and in nasal and inferior sectors for the peripapillary area. Nevertheless, further research with larger population and larger follow‐up is needed to obtain stronger results.