Choroidal Thickness and Urinary Albumin Excretion in Type 2 Diabetic Patients without Retinopathy

Abstract

The role of retinal vasculature’s dysfunction in the physiopathology of Diabetic Retinopathy (DR) has been extensively described. Recently, the existence of a diabetic choroidal vasculopathy has been proposed. The purpose of this study was to compare choroidal thickness (CT) in nondiabetic patients and in type 2 diabetic patients without retinopathy, using EDI SD-OCT. Additionally, considering the diabetic patient group, compare CT in patients with and without microalbuminuria. This retrospective study selected patients sent from primary health-care centers as part of the national screening of diabetic retinopathy. Inclusion criteria were diagnosis of type 2 diabetes mellitus, absence of diabetic retinopathy, and a 24 hours urinary albumin measurement in the last 3 months at the primary health-care center. Nondiabetic patients were selected from a database in the ophthalmology department, and only healthy patients were included. At the screening visit, all patients performed a complete ophthalmologic examination by the same examiner. All eyes were examined with SD- OCT, and all scans were performed in the EDI mode. Measurements were made at three points: subfoveal, 1500 μm temporally and nasally to the foveal center. We included 110 eyes of 110 diabetic patients without diabetic retinopathy and 30 eyes of 30 healthy controls. Mean subfoveal CT was greater in diabetic patients without retinopathy (with normoalbuminuria or microalbuminuria) when compared with nondiabetic patients (p<0.05). In diabetic patients without retinopathy, the subfoveal and temporal choroid was thicker among patients with microalbuminuria when compared with those of normoalbuminuric patients (p<0.05). The subfoveal and temporal choroid was thicker among diabetic patients with microalbuminuria compared with nondiabetic patients. (p<0.05). This study suggests that choroidal changes are present in type 2 diabetic patients even before the clinical development of retinopathy.

Choroidal thickness in relation to urinary albumin excretion rate in type 2 diabetes mellitus without retinopathy

“…Microalbuminuria was significantly correlated with a reduction in choroidal thickness and volume in diabetic patients without retinopathy [ 28 ]. On the contrary, Oliveira-Ferreira et al [ 18 ] in their retrospective study stated that the SFCT was higher in diabetic patients without DR when compared to nondiabetic patients. Microalbuminuria was accompanied by thickening of the subfoveal and temporal choroid in diabetic patients without DR when compared with normoalbuminuric diabetics and non-diabetics [ 18 ].…”

“…On the contrary, Oliveira-Ferreira et al [ 18 ] in their retrospective study stated that the SFCT was higher in diabetic patients without DR when compared to nondiabetic patients. Microalbuminuria was accompanied by thickening of the subfoveal and temporal choroid in diabetic patients without DR when compared with normoalbuminuric diabetics and non-diabetics [ 18 ]. These controversial results might be attributed to the manual measurement of CT in specified points rather than obtaining a map.…”

Early choroidal changes detected by swept-source OCT in type 2 diabetes and their association with diabetic kidney disease

“…Oliveira-Ferreira et al compared patients with T2D with normoalbuminuria or microalbuminuria, without DR, with healthy controls, and also found an increase of mean subfoveal CT in diabetics as well as thicker subfoveal CT and temporal CT in patients with T2D with microalbuminuria compared both with controls as normoalbuminuric patients. 24 In contrast, a recent meta-analysis suggested that subfoveal choroidal thickness is thinner in diabetic eyes compared with controls, and that the ratio of Pathophysiology/complications luminal areas (corresponding to the choroidal vascular lumens) is lower in diabetic eyes of patients without clinically detectable DR compared with control eyes. 25 26 Likewise, Ashour et al, in a study whose aim was to understand the effect of microalbuminuria on diabetic choroid, had found that patients with T2D have thinner CT compared with non-diabetic controls.…”

“…Oliveira-Ferreira et al compared patients with T2D with normoalbuminuria or microalbuminuria, without DR, with healthy controls, and also found an increase of mean subfoveal CT in diabetics as well as thicker subfoveal CT and temporal CT in patients with T2D with microalbuminuria compared both with controls as normoalbuminuric patients. 24 …”

Early Choroidal and Retinal Changes Detected by Swept-Source Oct in Type 2 Diabetes and Their Association with Diabetic Kidney Disease: A Longitudinal Prospective Study

“…Malerbi et al (2018) reported increased subfoveal choroid thickness in T1D with microalbuminuria vs normal UAE [20]. Oliveira-Ferreira et al (2020) also found thicker subfoveal and temporal CT in T2D patients with microalbuminuria compared to diabetics with normal UAE and healthy controls [23]. Increase of CT in the early stages followed by decrease were observed both in T1D as T2D patients [24] , [25].…”