ABSTRACT
PURPOSE: Retinal and choroidal microvascular changes can be related to renal impairment in hypertension and chronic kidney disease (CKD). The study examines the association between retinochoroidal parameters and renal impairment in hypertensive, non-diabetic patients. METHODS: This is a cross-sectional study on Caucasian patients with systemic arterial hypertension with different levels of renal function. All subjects were studied by blood chemistry, urine examination, microalbuminuria and blood pressure. Complete eye examination was completed with swept source optical coherence tomography (SS-OCT) and optical coherence tomography angiography (OCTA) scans of macular region. Patients were divided in groups: LowGFR and HighGFR and CKD- and CKD+, according to the value of glomerular filtrate (GFR) and albuminuria. LowGFR and CKD+ groups included patients with clinical kidney impairment. RESULTS: One hundred and twenty eyes of 120 hypertensive patients were evaluated. The mean retinal thickness was thinner in CKD+ versus CKD- group (p < 0.009). LowGFR and CKD+ groups showed thinner choroidal values than HighGFR (p < 0.02) and CKD- (p < 0.001) groups. OCTA showed lower density in LowGFR than in HighGFR group (p < 0.001) and in CKD+ versus CKD- group (p < 0.001). Albuminuria was inversely related to choroidal and retinal thickness measures (p < 0.001) and to the indices of superficial parafoveal (p < 0.05) and foveal (p < 0.05) vascular densities. CONCLUSIONS: CKD is associated with retinal thinning, eGFR and decreasing renal function with progressive reduction of choroidal and retinal vascular density. SS-OCT and OCTA documented close association between CKD and reduction of both choroidal thickness and paracentral retinal vascular density in hypertensive patients.
Subject(s)
Choroid/blood supply , Fluorescein Angiography/methods , Renal Insufficiency, Chronic/complications , Retinal Diseases/diagnosis , Retinal Vessels/pathology , Tomography, Optical Coherence/methods , Adolescent , Adult , Aged , Cross-Sectional Studies , Disease Progression , Female , Fundus Oculi , Humans , Hypertension/complications , Hypertension/diagnosis , Male , Middle Aged , Renal Insufficiency, Chronic/diagnosis , Retinal Diseases/etiology , Retrospective Studies , Young AdultABSTRACT
The introduction in the past few years of advanced optical coherence tomography (OCT) techniques has greatly increased our understanding of the choroid, which is the most important vascular layer of the eye. Our study aimed to assess choroidal thickness by using swept-source OCT (SS-OCT) in essential hypertensive patients (EHs) with and without early-stage chronic kidney disease (CKD). We enrolled 100 EHs, of whom 65 were without kidney damage, and 35 had stage 1-3 CKD. In all of the participants, SS-OCT and a routine biochemical workup were performed. Glomerular filtration rate (GFR) was estimated by the CKD Epidemiology Collaboration equation (eGFR). CKD was defined in agreement with the Kidney Disease Outcomes Quality Initiative Kidney Disease: Improving Global Outcomes 2002 guidelines. OCT measurements were performed according to the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol, which divides the macula into nine subfields. The circular grid consists of three concentric rings. EHs with CKD showed thinner choroidal thicknesses than those without it (all p < 0.05), even after adjustment for potential confounding factors. Overall choroidal thickness correlated significantly and directly with eGFR (r = 0.36) and negatively with urinary albumin excretion (r = -0.39). The association of choroidal thickness with CKD was confirmed in multiple logistic regression analyses once the effects of age and other confounding variables were accounted for. The odds ratio of having early-stage CKD associated with a standard deviation increase in overall choroidal thickness was 0.43 (0.24-0.75, 95% confidence interval; p = 0.007). In conclusion, our study confirms the close relationships between changes in ocular microcirculation and renal dysfunction.
