Subclinical ocular microvascular involvement in primary antiphospholipid syndrome and antiphospholipid antibody...

Investigate the role of antiphospholipid antibodies (aPL) in determining subclinical microvascular alterations in patients with primary antiphospholipid syndrome (PAPS) and antiphospholipid carriers, using posterior segment optical coherence tomography angiography (OCTA) and spectral-domain OCT (SD-OCT).

In this monocentric, cross-sectional study, PAPS and aPL-carrier patients and age-matched and sex-matched healthy controls were enrolled. OCTA and OCT were performed to assess vessel density (VD) in the superficial and deep retinal capillary plexi and to obtain high-resolution sectional retinal images.

38 patients from the aPL-cohort (30 PAPS and 8 aPL-carriers) and 32 matched healthy controls were enrolled. OCTA revealed reduced superficial and deep whole en face VD, particularly at the parafoveal level. SD-OCT demonstrated thinning of the central and outer regions of peripapillary retinal nerve fibre layer and of the macular, inner and outer plexiform, nuclear and nerve fibre layers. Increased thickness was observed in the inner inferior and superior regions across all retinal layers. No significant associations were found between OCTA parameters and disease duration, thrombotic risk profile, lupus anticoagulant positivity, cumulative drug exposure or treatments with low-dose aspirin or vitamin K antagonists. However, the VD in the superficial whole en face and parafoveal regions remained significantly reduced in the aPL-cohort after adjustment for age and cardiovascular risk factors.

Subclinical microvascular and structural damage occurs in aPL positive patients without ocular symptoms. This study suggests a possible independent effect of aPL, making the eye a unique, non-invasive window into aPL-related pathogenic mechanisms for early detection and longitudinal monitoring.