The blood pressure-induced diameter response of retinal arterioles decreases with increasing diabetic maculopathy

Abstract

The diameter response was reduced in type 2 diabetic patients with retinopathy, whereas retinal thickness was increased in patients with diabetic maculopathy. This suggests that impairment of diameter response in retinal arterioles precedes the development of diabetic macular edema.

The relationship of retinal vascular calibre to diabetes and retinopathy: the Australian Diabetes, Obesity and Lifestyle (AusDiab) study

“…Our findings of wider arterioles in people with retinopathy corroborates findings in studies from Denmark [29,30] and Iceland that support a hypothesis that a disturbance in the autoregulation of retinal arterioles resulting in arteriolar dilatation may be the cause of hyper-fusion, haemorrhage and microaneurysm formation resulting in macular oedema [31][32][33].…”

The Systemic Blood Pressure and Oxygen Saturation in Retinal Arterioles Predict the Effect of Intravitreal Anti-VEGF Treatment on Diabetic Maculopathy

“…22,23 The amount of oxygen and other compounds exchanged between the central retinal arteriole and venule in the optic nerve will depend on the amount of blood per time unit exposed to the diffusion area between the vessels, and an increased arterial oxygen saturation in retinal vessels, therefore, can be interpreted as a consequence of increased flow rate in the central retinal vessels. A higher retinal blood flow combined with increased arterial blood pressure and impaired retinal pressure autoregulation 24 may increase the hydrostatic pressure in the capillaries and the stress on the walls may counteract the tightening effect of anti-VEGF medication on the blood-retina barrier. This may explain how increased systemic blood pressure and oxygen saturation in retinal arterioles can contribute to increasing CRT with a consequent reduction in visual acuity.…”

Biomarkers in Diabetic Retinopathy

“…Later in the retinal disease process, retinal arterioles dilate, which causes increased blood flow [98,100] and accelerated progression to diabetic macular edema (DME) and PDR [101]. Increased blood pressure induced by exercise, acute hyperinsulinemia, and the degree of diabetic retinopathy present can alter retinal vessel vasodilatory capacity, which can be measured at rest or after exercise [102][103][104].…”

“…With the advent of digital retinal photos and semi-automated software to grade retinal calibers, many cross-sectional and longitudinal studies, relating vessel caliber to retinal and renal outcomes, have been conducted (reviewed in [41,118,119]), including by the author and her colleagues [122][123][124]. Most studies of retinal caliber are at rest, but some investigators also evaluate the retinal vessel caliber response to exercise [102][103][104].…”

“…Reduced retinal arteriole caliber has also been associated with diabetic retinopathy [99,127] in a cross-sectional study, and in several prospective studies in type 1 diabetes [122,124]. In a longitudinal study of 64 type 2 diabetes patients (followed up over a mean of 6.8 years), resting retinal arteriole diameter decreased significantly in patients with improved diabetic retinopathy [102]. To the best of our knowledge, the longest longitudinal study to date is the 16-year Danish Cohort of Pediatric Diabetes study, in which wider veins and smaller arterioles were independent predictors of proliferative retinopathy, nephropathy, and neuropathy [126].…”