Microvascular Ocular Changes of Systemic Lupus Erythematous

Systemic inclusion criteria for SLE patients: * fulfill the 2019 European League Against Rheumatism (EULAR) / American College of Rheumatology (ACR) classification criteria for the diagnosis of SLE * age between 18 and 80 years * no disease activity (SLEDAI \<3) * no risk factors for drug toxicity Systemic inclusion criteria for control group: * no systemic diseases * age between 18 and 80 years Systemic exclusion criteria: * arterial hypertension (defined as systolic blood pressure higher than 140 mm Hg or diastolic blood pressure higher than 90 mm Hg) or medically treatment for hypertension * diabetes mellitus * nephropathy or other documented microvascular complications * secondary Sjögren syndrome * local or systemic inflammatory diseases (other than SLE) * smokers of more than 20 cigarettes a day * pregnancy. Ophthalmological inclusion criteria: * best-corrected visual acuity ≤ 0.3 LogMAR * intra-ocular pressure \<21 mm Hg on diurnal testing with measurements using Goldmann applanation tonometry * spherical equivalent refractive error between -6.0 and +4.0 diopters * open anterior chamber angle on slit lamp examination. Ophthalmic exclusion criteria: * established primary ocular diseases including a history of any retinal or optic nerve disease * presence of significant lens opacities (Lens Opacities Classification System III equal to or more stage 2) * retinopathy * high refractive error * ocular hypertension * previous intraocular surgery or trauma.