Assessing Retinal Microvascular Perfusion in Systemic Sclerosis

Retinal microcirculatory impairment can be demonstrated in patients with systemic sclerosis (SSc) and no ophthalmologic symptoms using optical coherence tomography angiography (OCTA), according to the results of a small, proof-of-concept, case-control study. Findings from the analysis were published in the Annals of the Rheumatic Diseases.

The investigators sought to evaluate retinal microvascular blood flow in patients with SSc and no clinical signs of retinal involvement, with the use of OCTA. The age-matched, sex-matched case-control study was performed in a total of 24 eyes of 12 patients with SSc and 12 healthy matched control participants, all of whom were examined with OCTA and underwent basic ophthalmologic and rheumatologic examinations.

OCTA is a noninvasive technique that generates angiographic images based on motion contrast imaging to high-resolution volumetric blood flow information. The technique permits the quantification of perfused and nonperfused areas of the retina in primarily ocular pathologies, but it also mirrors vascular involvement in such systemic diseases as systemic lupus erythematosus. The OCTA device uses a modified, full-spectrum amplitude decorrelation algorithm to generate angiograms of the full retina, as well as the automatically segmented slabs of both the superficial retinal plexus (SRCP) and the deep retinal capillary plexus (DRCP). For each participant, perfusion values from both eyes were averaged.

The results of the study showed that patients with SSc had a significantly lower retinal perfusion compared with patients with healthy eyes (29% vs 32%, respectively; P =.037). According to substructure analysis, these differences were located primarily in the SRCP (21% vs 25%, respectively; P =.006) rather than in the DRCP (38% vs 40%, respectively; P =.061).

Moreover, in patients with SSc, the perfusion in the full retina slab correlated significantly with macular volume (P =.041), as well as with mean arterial pressure (P =.041). Furthermore, best-corrected visual acuity was associated significantly with perfusion in the SRCP (P = .018) and the DRCP (P =.023) slabs.

The investigators concluded that OCTA-based analysis of retinal perfusion might provide a new quantitative metric that is much quicker to obtain and is also more independent with respect to classification compared with nailfold capillaroscopy. Additional multicenter analyses are warranted that include a larger number of participants and greater clinical diversity to validate these findings.

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Reference

Rothe M, Rommel F, Klapa S, et al. Evaluation of retinal microvascular perfusion in systemic sclerosis: a case-control study [published online January 3, 2019]. Ann Rheum Dis. doi:10.1136/annrheumdis-2018-214541