It has been recognised that elevated intraocular pressure (IOP) exerts direct mechanical damage to the optic nerve head (ONH). Clinical implications, recent new advances in retinal vascular imaging (eg, optical coherence tomography angiography) and future research directions are also discussed.ĭespite the critical impact of glaucoma on global blindness, its aetiology is not fully characterised. This review summarises recent findings on the relationships between quantitatively measured structural retinal vascular changes with glaucoma and other markers of optic nerve head damage, including retinal nerve fibre layer thickness.

Several population-based and clinical studies have reported that changes in retinal vasculature (eg, retinal arteriolar narrowing and decreased fractal dimension) are associated with optic nerve damage and glaucoma, supporting the vascular theory of glaucoma pathogenesis. As the retinal vasculature is the only part of the human circulation that readily allows non-invasive visualisation of the microcirculation, a number of quantitative retinal vascular parameters measured from retinal photographs using computer software (eg, calibre, fractal dimension, tortuosity and branching angle) are currently being explored for any association with glaucoma and its progression. Vascular factors have been suggested to play a role in glaucoma development, based on numerous studies showing associations of glaucoma with blood pressure, ocular perfusion pressure, vasospasm, cardiovascular disease and ocular blood flow. However, visual field loss still progresses in some patients with normal or even low intraocular pressure. Elevated intraocular pressure is highly associated with glaucomatous optic neuropathy.

Despite the critical impact of glaucoma on global blindness, its aetiology is not fully characterised.

Review calibre 2018