Background/Purpose:

Rheumatoid arthritis (RA) is associated with a chronic inflammatory state, accelerated atherosclerosis and excess cardiovascular risk. Quantification of morphological changes in the retinal microvasculature has emerged as a novel biomarker for cardiovascular health¹. These include narrower retinal arterioles, wider venules and a decrease in their ratio (retinal arteriovenous ratio, AVR), which represents an important parameter as it is widely used, can be objectively measured, and adjusts for both arterioles and venules. The present study examines retinal AVR for the first time in patients with RA, particularly in regard with systemic inflammation and subclinical atherosclerosis.

Methods:

Consecutive RA patients and age-, gender- and blood pressure-matched volunteers underwent nonmydriatic digital fundus photography with a NIDEK AFC-230/210 camera. Images were processed using a validated computerized semi-automated system, which measures vessel width in arterioles and venules, to obtain central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE), respectively, as well as their ratio (AVR)². Carotid ultrasound (Aloka Prosound A7) was used to assess subclinical atherosclerosis by measurement of carotid intima-media thickness (cIMT) in each common carotid artery.

Results:

A total of 129 individuals, 87 RA patients and 42 controls, with a mean age of 58.8±10.9 years, were studied. Patients exhibited narrower retinal arteriolar caliber (78.8±8.9 vs 93.9±8.0 μm, p<0.001), whereas retinal venular caliber did not differ compared to controls (115.0±14.8 vs 112.7±11.9 μm, p=0.381); accordingly, AVR was significantly decreased in RA patients (0.69±0.09 vs 0.84±0.09, p<0.001). Subclinical atherosclerosis was more pronounced in RA patients, who presented increased cIMT compared to controls [0.67 (0.60 – 0.77) vs 0.59 (0.55 – 0.67) mm, p=0.006]. In the univariate analysis, AVR inversely correlated with both C-reactive protein (CRP) (r=–0.449, p<0.001) and cIMT (r=–0.232, p=0.035) in the RA group. On the contrary, disease duration and activity appeared to have no effect on AVR in patients with RA. In the linear regression analysis accounting for age, sex, and hypertension, the association between AVR and cIMT was no longer significant (p=0.453), whereas CRP was identified as an independent prognostic factor of AVR (p=0.045).

Conclusion:

Quantitative evaluation of the retinal vessel morphology in our study revealed that patients with RA exhibit lower AVR compared to controls, mainly as a result of narrower arterioles. The heightened inflammatory state in these patients appears to be the biological link for the observed association between AVR and subclinical atherosclerosis.

References

1. Sun C, et al. Retinal vascular caliber: systemic, environmental, and genetic associations. Surv Ophthalmol 2009;54:74-95.

2. Manikis G, et al. An Image Analysis Framework for the Early Assessment of Hypertensive Retinopathy Signs. International Conference on e-Health and Bioengineering; November 24–26, 2011; Iasi, Romania. Available at: http://www.ics.forth.gr/~zabulis/EHB11_Retina_Analysis.pdf Last accessed June 11, 2017.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/retinal-vessel-morphological-associations-with-systemic-inflammation-and-subclinical-atherosclerosis-in-patients-with-rheumatoid-arthritis/