Background/Aim: Diabetic retinopathy is a common ailment that causes visual impairment among adults, and evidence suggests that oxidative stress plays a significant role in its pathogenesis. The objective of this study was to examine the potential association between selenium deficiency and an increased risk of diabetic retinopathy among individuals with type 2 diabetes mellitus. Methods: This study was a prospective case-control study. 115 patients with a diagnosis of type 2 diabetes mellitus were included. The patients were divided into groups with and without retinopathy. No subgroups were made according to the level of retinopathy. The aim was to compare the serum selenium level of patients between groups. Therefore, other variables that may contribute to the development of retinopathy were also recorded. The duration of diabetes, medications used, and glycosylated hemoglobin levels were recorded. The retinopathy group included 47 patients, and the non-retinopathy group included 68 patients. Selenium levels were measured in plasma samples. Results: The mean selenium level of the retinopathy group (70.11 [17.28] μg/l) was significantly lower than that of the non-retinopathy group (80.20 [19.10] μg/l) (P=0.005). The median duration of diabetes mellitus was significantly higher in the retinopathy group than in the non-retinopathy group (10 [1-25] and 6 [1-21], respectively; P=0.002). Logistic regression analyses showed that higher levels of blood selenium were independent preventive factors against the occurrence of retinopathy (OR [95% CI]: 0.965 [0.939-0. 991]). The duration of diabetes mellitus was an independent risk factor for retinopathy occurrence [OR (95% CI): 1.131 (1.050-1.219)]. One unit increase in selenium level was associated with a unit decrease in diabetic retinopathy of 0.965 (0.939-0.991). Conclusion: Our research revealed a correlation between the duration of diabetes and the incidence of diabetic retinopathy. Furthermore, a notable difference was observed in blood selenium levels between patients with diabetic retinopathy and those without it. Specifically, patients with diabetic retinopathy had lower plasma selenium levels compared to the control group. These findings have potential implications for the treatment or prevention of diabetic retinopathy, but more research is needed to determine the efficacy of selenium supplementation for diabetic patients with or without microvascular complications. Future studies should investigate the effect of selenium deficiency on different subtypes of diabetic retinopathy and the impact of selenium supplementation in this patient population.

Background/Aim: The prevalence of hypertension increases with age and one out of every three adults over the age of 40 has hypertension. Hypertensive end-organ damage is an important predictive factor for patient morbidity and mortality. This study aimed to investigate the role of the renal resistive index (RI) in predicting retinopathy and nephropathy in hypertensive patients. Methods: This study was cross-sectional in design. Sixty hypertensive patients who were followed in Samsun Research and Training Hospital Internal Medicine outpatient clinic were included in the study. In all patients, a routine ophthalmological examination, including visual acuity, anterior segment examination, and dilated ocular fundus examination, was performed. Urinary albumin to creatinine ratio (mg/g) was measured in spot urine samples, and a level ≥30 mg/g was accepted as the presence of proteinuria. Renal Doppler ultrasonography was performed using Esaote mylab x 9 model sonography device vovex probe (C1-8) 3.5 MHz. RI values were measured using Xflow Doppler at the level of interlobular or arcuate arteries of both kidneys. First, the patients were divided into two groups (with or without retinopathy). The patients who had retinopathy were then divided into two groups according to their retinopathy degree. Hypertensive retinopathy was graded according to the Scheie classification. The patients were also divided into two groups according to their proteinuria status (with or without proteinuria). Results: The mean of renal RI was 0.59 (0.04) in patients without retinopathy (n=15), 0.63 (0.05) in patients with grade 1 hypertensive retinopathy (n=29), and 0.66 (0.04) in patients with grade 2 hypertensive retinopathy (n=15). The difference between groups was statistically significant (overall P=0.001). It has been shown that proteinuria develops more frequently in cases in which the renal value is above 0.7, and these results were statistically significant (P=0.034).  Conclusion: This study indicates that renal RI increase is a valuable tool for estimating retinopathy and proteinuria in hypertensive patients.