Objective: To analyze the glutathione antioxidant defense system changes in the tear and serum of patients with hypertensive retinopathy (HR) and to establish whether there is an interdependence between their levels and HR degree. Methods: 90 patients were split into three groups according to the Keith-Wagner-Barker grading of HR: GI–36 patients; GII–35 patients; GIII–19 patients. The concentration of reduced glutathione (GSH) and activities of glutathione peroxidase (GPx) and glutathione reductase (GR) in tear and serum were measured. Results were analyzed by ANOVA, followed by Bonferroni post hoc test. The Spearman correlation coefficient was calculated (p≤0.05 statistically significant). Results: In serum, the GSH level and GPx activity were not statistically changed between groups with HR degree advancement, unlike the GR activity that was statistically diminished (p=0.018). The values of the studied markers in the tear showed a decrease with the progression of the HR degree. Only serum GSH level correlated with the tear one (r=-0.361, p=0.000), while the enzymes activity did not. A correlation of GPx and GR activity (r=0.417, p=0.000) was identified in tear, while in serum - of GPx activity and GSH level (r=409, p=0.000). Tear GPx and GR levels correlated significantly but with low power with HR degree (r=0.299, p=0.004/ r=0.299, p=0.004). Conclusion: Statistically significant elevation in tear GPx and GR activity and a tendency of GSH level increase was revealed, being attested, and a direct correlation between GPx and GR activity, as well as of their activity with the HR degree. In serum, the GSH level and the GPx activity did not change accurately, while the GR activity diminished significantly, the identified decrease being correlated with the HR degree. Abbreviations: HR = hypertensive retinopathy, HTN = hypertension, GSH = reduced glutathione, GPx = glutathione peroxidase, GR = glutathione reductase, GGR = gamma-glutamyl transferase, ROSs = reactive species of oxygen, OS = oxidative stress

Background. Hypertension (HTN) is a preventable risk factor for morbidity and mortality worldwide. Hypertensive retinopathy (HR), its ocular complication, is characterized by progressive metabolic disorders and structural damage of the retina. Lipids play an essential role in retina homeostasis, so an alteration of lipid metabolism specific for HTN may be of great significance in the development of hypertensive retinal injury. The study aimed to investigate the association between HR, traditional lipid biomarkers changes, and the atherogenic index, as well as to highlight a possible role of lipid metabolism markers in HR diagnosis and prognosis. Methods. A total of 90 hypertensive patients from the Republic of Moldova, admitted to the Ovisus Medical Center, Chisinau, Republic of Moldova, for a vision check and firstly diagnosed with HR were recruited in our study. The enrolment period is between February 2018 and December 2019. They were divided into three groups based on fundoscopy, using Keith-Wagner-Barker grading system of HR-GI: 36 patients; GII: 35 patients; GIII: 19 patients. The level of serum lipids: triglycerides, total cholesterol, LDL-Chol, and HDL-Chol was determined, followed by the calculation of the atherogenic index of plasma. Results are displayed as the median and interquartile range (IQR). Kolmogorov-Smirnov and Shapiro-Wilk normality tests were used, followed by Levene's homogeneity of variance test. The groups were compared using the non-parametric Kruskal-Wallis and Mann-Whitney tests. The Spearman correlation coefficient was calculated (SPSS 23.0): p < 0.05-statistically significant. Results. It was attested a statistically significant increase of serum total cholesterol levels between the groups as the HR advanced (p = 0.017). In paired group comparisons, the total cholesterol level in GII significantly enhanced compared to GI 5.63 (IQR 0.69) mM/L vs. 5.49

Background. Hypertension (HTN) is one of the leading causes of morbidity and mortality worldwide. A prompt diagnosis and treatment of hypertensive retinopathy (HR), the leading complication of HTN is pivotal for a better visual outcome. Increased blood pressure on its own cannot fully clarify the development of retinal alterations, therefore an additional pathogenetic mechanism, such as oxidative stress, might be inquired. The aim of the study was to evaluate the changes in the level of ischemia modified albumin (IMA) in the serum and tears of HR patients in order to establish the predictive value of IMA for the HR progression. Methods. Serum and tear samples for the measurement of IMA were collected from 90 patients detected primarily with HR, who were not taking any antihypertensive or other drug that could influence the results of the study, divided according to the Keith-Wagener classification into GI ‒ 36 patients with HR grade I, GII ‒ 35 with HR grade II and GIII ‒ 19 with HR grade III. Serum and tear IMA levels were assessed using the Co2+ binding method (Gudumac V. et al., 2009) and expressed as median and interquartile range. Kruskal-Wallis and Mann-Whitney nonparametric tests were used to compare the groups and the Spearman correlation coefficient was calculated (SPSS 23.0), with p<0.05 being statistically significant. Results. The groups showed a statistically significant difference in serum IMA (p=0.006), the values increasing in parallel with the progression of HR. The serum IMA level in GII increased compared to GI (+3%; 239.06 µM/L (IQR 75.58) vs 231.77 µM/L (IQR 104.09), p=1.00), as well as in GIII patients compared to GII (+17%; 277.67 µM/L (IQR 88.72) vs 239.06 µM/L (IQR 75.58), p=0.04). There were no differences in IMA content (p=0.160), between groups in the tears. No correlations were found between serum and tear IMA levels (p=0.134), but serum IMA showed a significant moderate strength, positive correlation with the degree of HR (r=0.307**, p=0.003). Conclusion. A progressive enhancement in serum IMA level as HR advanced was identified. Thereby, the results suggest the potential relevance of serum IMA as a sensitive and early biomarker useful for grading and optimal treatment of the patients with HR.

Background. Diabetic retinopathy (DR) is the most common ocular complication of diabetes mellitus, as well as the most prevalent cause for irreversible vision loss in working-age population. The aim of the study was to analyze the association between DR in patients with type 1 diabetes mellitus (T1DM), some lipid biomarkers changes, as well as to highlight the possible correlation. Methods. A total of 72 T1DM patients were included in this study. The enrolled participants were assigned into three groups, based on the results of fundus photographs as following: 1st group - no DR, 2nd group - non-proliferative diabetic retinopathy (NPDR), and 3rd group - proliferative diabetic retinopathy (PDR). Serum lipids: triglycerides (TG), total cholesterol (TC) and lipoprotein (a) (Lp (a)) were measured at the baseline. Results. The data revealed no difference in TG serum levels in patients of the 1st and 2nd groups. The increase of TG serum levels was identified with the progression of the DR in the 3rd group (+121%, p=0.018). TC also rose in patients in the 3rd study group (+19%, p>0.05 compared to the 1st and 2nd study groups). An increase of Lp (a) was highlighted with the evolution of DR: in the 2nd group (+73%, p>0.05) and in the 3rd group (by about 320%, p=0.019) compared to 1st study group. The correlation analysis revealed a weak positive correlation between the grade of DR and Lp (a) levels (rs=0.319, p=0.006), and TG (rs=0.239, p=0.043). Conclusion. Our study exposed statistically significant modifications of the TG and Lp (a) levels correlated with the DR grade and a non-significant increase in TC level in T1DM persons. Our data indicate a likely involvement of lipid metabolism disorders in the progression of DR.

The objective was to determine the changes in SOD and catalase activity, markers of oxidative stress/antioxidant balance in serum and tear of patients with hypertensive retinopathy and to identify whether there was a correlation between their levels and HR degree of hypertensive retinopathy (HR). Material and Methods — 90 hypertensive patients were divided in three groups, according to the Keith-Wagener classification: GI-36, GII-35 and GIII-19. SOD was assessed using the Dubinina and Matyushin method and catalase according to Koroliuk, both in modification of Gudumac V. The results were presented by median and interquartile range. The groups were compared using Kruskal-Wallis and Mann-Whitney nonparametric tests, and the Spearman correlation coefficient was calculated (SPSS 23.0). Results — Showed a statistically significant difference of SOD in serum (p=0.035) and tear (p=0.027) between groups. SOD decreased from GI until GIII in serum (-8%, p=0.032) and tear (-16%, p=0.031). In addition, it showed a weak significant negative correlation with the HR degree both in serum (r=-0.246, p=0.019) and tear (r=-0.284, p=0.007), while the correlation attested between serum and tear SOD levels was significant moderate and positive (r=0.336, p=0.001). It was noted a significant catalase elevation in the tear (p=0.033). In serum it was not correlated with HR degree, while in tear showed a significant weak strength, positive correlation (r=0.261, p=0.013). No correlations were found between serum and tear catalase levels. Conclusion — A progressive significant decrease in SOD levels and a tendency to increase of catalase activity was identified as HR advanced both in serum and in tear. The enhancement in the severity of HR was correlated with decreased SOD activity in tear and serum and increased catalase level in tear.