Liu M, Lovern C, Lycett K, et al. - Findings provide stronger evidence for a link of inflammation with retinal venular than with arterial caliber. A potential druggable mechanism was indicated which contributes to microvascular damage that has been relatively overlooked in cardiovascular disease pathogenesis and management.

• Medline, Embase and PubMed were explored for relevant studies up to April 2021.

• Overall 4,783 studies were identified; 36 were eligible, and a meta-analysis comprising 11 C-reactive protein (CRP) studies (22422 participants) and six white blood cell count (WBC) studies (15,209 participants), as well as a narrative review of all studies, was conducted.

• Consistent evidence showing a modest relationship between CRP and venular caliber, but little evidence for a link between CRP and retinal arteriolar caliber, was found.

• Similarly, stronger associations of WBC with venular than with arteriolar caliber were evident.

• Consistent results were obtained via narrative review of other inflammatory markers.

• Little evidence for links between inflammation markers and other microvascular parameters, fractal dimension and tortuosity, was found.