Severe tortuosity but not altered retinal vessel diameters in children and young adults with Familial Mediterranean Fever: a case-control study.

Familial Mediterranean Fever (FMF) is the most prevalent autoinflammatory disorder. The objective of the present study was to evaluate the potential association between retinal vascular abnormalities and an increased risk of cardiovascular disease in patients with FMF. A total of 42 patients with FMF and 43 age- and sex-matched healthy controls were enrolled in this study. All participants underwent bilateral fundus examination and fundus photography using a non-mydriatic fundus camera. Retinal microcirculation was evaluated by measuring the calibers quantitatively by calculating the central retinal artery and vein equivalent (CRAE and CRVE, respectively) and qualitatively by estimating the tortuosity. Furthermore, microcirculation was assessed with the measurement of Augmentation Index and the subendocardial viability ratio and macrocirculation was assessed via arterial stiffness by carotid–femoral pulse wave velocity and by carotid intima–media thickness. Both micro- and macrovascular indices were correlated with laboratory parameters and inflammatory markers. A significant difference in the prevalence of severe tortuosity was observed between FMF patients and controls (23.8% vs. 2.3%, respectively; p = 0.003), with similar results in the pediatric subgroup. In multivariable analysis using Firth penalized logistic regression, FMF status was independently associated with severe retinal tortuosity (adjusted OR 12.6, 95% CI 1.69–316.35, p = 0.009), after adjustment for amyloid, CRAE, and PAI-1. No statistical differences were identified between FMF and controls regarding retinal vessel diameters. These findings support those retinal vascular abnormalities—particularly severe tortuosity—may reflect early microvascular involvement and could serve as a non-invasive variable related to cardiovascular risk in patients with FMF. Although, more studies are needed to verify whether these alterations are also present in other children’s diseases, as well as their role in disease assessment and progression.