Purpose: To evaluate whether retinal vascular density, measured using optical coherence tomography angiography (OCTA), can differentiate healthy, ocular hypertensive (OHT), and mild-to-moderate primary open-angle glaucoma (POAG) eyes, and to examine its correlation with retinal nerve fibre layer (RNFL) thickness and visual field changes. Materials and Methods: A cross-sectional study of 54 eyes (19 normal, 18 OHT, 17 POAG) was conducted using swept-source (SS) OCTA to image the optic disc region (3 mm × 3 mm scans). Vessel density was measured in the optic nerve head, papillary, peripapillary and superior and inferior papillary areas using ImageJ Fiji. RNFL thickness was assessed with SS-OCT and visual fields were evaluated using Humphrey perimetry. Comparisons were analysed using ANOVA, Bonferroni post hoc tests and receiver operating characteristic analysis. Results: Vascular density showed a significant descending trend: Normals > OHT > POAG ( P 72.42% (Normal), 62.16–72.42% (OHT) and <62.16% (POAG). RNFL thickness and mean deviation (MD) correlated positively with vessel density, with decreasing vascular density associated with reduced RNFL thickness ( r = +0.61, P < 0.01) and MD ( r = +0.55, P < 0.01). Early inferior RNFL thinning was seen in OHT eyes, even though mean RNFL thickness was normal. Conclusion: OCTA-derived retinal vessel density measurements demonstrate significant associations with RNFL thickness and visual field indices and show potential in differentiating normal, OHT and early POAG eyes, with inferior papillary and peripapillary regions showing greatest accuracy. Reduced vessel density was significantly associated with RNFL thinning and visual field changes, highlighting its potential role in pre-perimetric glaucoma detection. However, given the cross-sectional design and modest sample size, these findings should be interpreted as preliminary. The proposed vessel density cut-offs are exploratory and require external validation before clinical implementation. Longitudinal studies are needed to clarify the temporal relationship between vascular and RNFL changes in glaucoma.
Kumar et al. (Wed,) studied this question.