Evaluation of near accommodation in type 1 diabetic patients

Aim: To evaluate accommodation in type 1 diabetic patients by PowerRef3 in our study. The PowerRef 3 can be used in studying the near triad of accommodation, vergence and pupil responses in healthy and clinical populations. Method: The accommodation of 14 patients (mean age: 33.14 ± 10.27) with type 1 diabetes and 16 control subjects (mean age: 35.81 ± 5.88) were measured by PowerRef3 at 30 cm with a standard accommodation target. The metabolic status of the diabetic patients and accommodation were compared with those of control subjects. Results: The mean accommodation, spherical equivalents and age was not significantly different between diabetic and control subjects.  The mean duration of diabetes was 13 ± 5.7 years (min: 7, max: 27). The mean accommodation was not significantly correlated with duration of diabetes and glycated hemoglobin levels, but it was significantly correlated with the spherical equivalents (p<0.05) and weakly correlated other metabolic parameters (fasting plasma glucose, cholesterol, low density lipoprotein, high density lipoprotein and triglyceride levels). Conclusion: The accommodation of type 1 diabetes patients at pre-presbyopic ages without diabetic retinopathy was similar to control subjects with PowerRef 3 measurements. This may reflect that good diabetes control, which will prevent retinopathy, may prevent the decrease in accommodation in type 1 diabetes patients

Evaluation of biochemical and clinical markers of endothelial dysfunction and their correlation with urinary albumin excretion in patients with type 1 diabetes mellitus

ABSTRACT Objective Endothelial dysfunction (ED) plays an important role in the pathogenesis of diabetic nephropathy. The purpose of the study was to determine flow mediated endothelial dependent vasodilatation (FMD) measurements and serum soluble (s) endothelin-1 (ET-1), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1) levels in patients with type 1 diabetes mellitus (T1DM) with or without increased urinary albumin excretion (UAE) and compare them with the healthy controls. Subjects and methods Seventy three patients with T1DM were enrolled. Patients were divided into two subgroups according to microalbumin measurements in 24-hr urine collections. The diabetic patients without microalbuminuria (41 patients) were defined as Group I and those with microalbuminuria (32 patients) were defined as group II. A hundred age and sex matched healthy subjects participated as the control group (Group III). Serum sET-1, sICAM-1, sVCAM-1 levels and FMD measurements were determined in all participants. Results Median FMD measurement was significantly lower in the diabetic groups compared with the control group (6.6, 6.4 and 7.8% in Group I, II and III, respectively) (p < 0.05). FMD was negatively correlated with age (p = 0.042). Median serum sICAM-1 level was higher in the patient groups compared to the control group (p < 0.05). Median serum sVCAM-1 level was higher in the group of patients with increased albuminuria compared to the normoalbuinuric and the control group (p < 0.05). Serum sVCAM-1 level was found to be positively correlated with degree of urinary albumin excretion (p < 0.001). Conclusion We assume that sVCAM-1 may be used as a predictive marker for risk stratification for nephropathy development and progression

Investigation of Oxidative and Antioxidative Status in Patients with Diabetic Cataracts

Aim: To investigate the oxidative and antioxidative status in diabetic patients with cataracts and nondiabetic patients with cataracts as compared to controls. Materials and methods: There were 149 subjects included in the present study. Blood was collected from type 2 diabetic patients suffering from cataracts (diabetic cataract; n = 42), senile nondiabetic patients suffering from cataracts (nondiabetic cataracts; n = 60), and healthy subjects of a control group (n = 47). Serum levels of total oxidant status (TOS), total antioxidant status (TAS), total thiol levels (TTLs), and paraoxonase 1 (PON1) were investigated in the samples. Results: TTLs were significantly reduced in diabetic cataract patients (444.8 mu mol/L) compared with both nondiabetic cataract patients (525.1 mu mol/L) and the control group (569.9 mu mol/L). Plasma PON1 levels also were significantly reduced in diabetic cataract patients (241.9 U/L) relative to the control group (178.3 U/L). There were no statistically significant differences between TAS and TOS levels among groups. Conclusion: The present study demonstrates a significant reduction in serum TTLs and serum PON1 activities in diabetic cataract patients compared with controls. These findings represent a failure in the antioxidant system, which may be related to the cataractogenic process.WoSScopu

Evaluation of Serum Fibrinogen, Plasminogen, α2-Anti-Plasmin, and Plasminogen Activator Inhibitor Levels (PAI) and Their Correlation with Presence of Retinopathy in Patients with Type 1 DM

Background. Diabetic retinopathy (DR) is the leading cause of blindness in the world. Retinopathy can still progress despite optimal metabolic control. The aim of the study was to determine whether different degrees of DR (proliferative or nonproliferative) were associated with abnormally modulated hemostatic parameters in patients with T1DM. Method. 52 T1DM patients and 40 healthy controls were enrolled in the study. Patients were subdivided into three categories. Group I was defined as those without retinopathy, group II with NPRP, and group III with PRP. We compared these subgroups with each other and the control group (Group IV) according to the serum fibrinogen, plasminogen, alpha2-anti-plasmin (α2-anti-plasmin), and PAI. Results. We detected that PAI-1, serum fibrinogen, and plasminogen levels were similar between the diabetic and control groups (P=0.209, P=0.224, and P=0.244, resp.), whereas α2-anti-plasmin was higher in Groups I, II, and III compared to the control group (P<0.01, P<0.05, and P<0.001, resp.). There was a positive correlation between serum α2-anti-plasmin and HbA1c levels (r=0,268, P=0.031). Conclusion. To our knowledge there is scarce data in the literature about α2-anti-plasmin levels in type 1 diabetes. A positive correlation between α2-anti-plasmin with HbA1c suggests that fibrinolytic markers may improve with disease regulation and better glycemic control

Decreased UV-filtering ability of corneal epithelium may be the cause of stromal pathologies in keratoconus

Annual Meeting of the Association-for-Research-in-Vision-and-Ophthalmology (ARVO) -- MAY 07-11, 2017 -- Baltimore, MDYILDIRAN, Fatma Azize BUDAK/0000-0001-7031-6834;WOS: 000432170306360…Assoc Res Vis & OphthalmolTurkish Scientific and Technical Research InstituteTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)Support Turkish Scientific and Technical Research Institut

Evaluation of the correlation between quantitative measurement of the foveal avascular zone and retinal vessel density and outer retinal disruptions in diabetic patients

Background/aim: The aim of the current study was to evaluate the correlation between the integrity of the outer retinal layers on optical coherence tomography (OCT) and objective parameters of retinal microvascular perfusion on optical coherence tomography angiography (OCTA). Materials and methods: A total of 105 eyes of 54 diabetic patients were included in the study. Integrity of the outer retinal layers including the external limiting membrane (ELM), ellipsoid zone (EZ), and interdigitation zone (IZ) was assessed by spectral-domain optical coherence tomography. The foveal avascular zone (PAZ) area and vessel density (VD) measurements in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in all the Early Treatment Diabetic Retinopathy Study (ETDRS) sectors were evaluated by OCTA. Associations between the quantitative measurement of the PAZ and retinal VD measurements and outer retinal disruptions were evaluated. Results: The FAZ area was correlated with outer retinal layer disruption both in the superficial plexus (r 0.244, 0.228, 0.212, P= 0.013, 0.02, 0.031 for the ELM, EZ, and IZ, respectively) and the deep capillary plexus (r = 0.298, 0.234, 0.197, P = 0.002, 0.019, 0.048 for the ELM, EZ, and IZ, respectively). A significant relationship was also found between the VD measurements in the SCP and DCP in ETDRS sectors and the outer retinal layers disruption. Conclusion: The results of the current study show a significant relationship between the quantitative OCTA parameters and the integrity of the outer retinal layers. This finding reveals a correlation between retinal capillary nonperfusion and outer retinal disruption in eyes with diabetic retinopathy

Effect of vitamin D deficiency on ocular blood flow

Aim: In this study, we aimed to evaluate the effects of vitamin D deficiency (VDD) on retrobulbar blood flow in healthy eyes.Material and Methods: In this prospective study, thirty eyes of 30 patients with VDD (Group 1) and 25 eyes of 25 individuals without VDD (Group 2) were included. The peak systolic flow velocity (PSV), end-diastolic flow velocity (EDV) and vascular resistance index (RI) were obtained from the ophthalmic artery (OA) with color doppler imaging. Multiple linear regression was performed for the covariate-adjusted comparison.Results: Mean ages were 37.83 +/- 9.89 years in Group 1 and 35.32 +/- 9.61 years in Group 2, (p = 0.347). Mean values of serum 25(OH)D3 level were 11.38 +/- 3.85 ng/dl in Group 1 and 26.80 +/- 10.03 ng/dl in Group 2 (p < 0.001). PSV and EDV were significantly higher in Group 2 than in Group 1 (p<0.001, p=0.001, respectively). RI was slightly higher in Group 1 than in Group 2, but this difference was not statistically significant. In multivariate linear regression, PSV and EDV were positively correlated with OPP, and negatively affected by the presence of VDD.Discussion: VDD can be an important factor in reducing ocular blood flow

Transscleral Delivery of Bevacizumab-Loaded Chitosan Nanoparticles

asik, Mehmet/0000-0001-9154-2697;WOS: 000460555500017PubMed: 30841975Purpose: The aim of this study was to synthesize bevacizumab-loaded nanoparticles and evaluate their effects on the treatment of posterior segment diseases via subtenon injections. Methods: Bevacizumab-loaded chitosan nanoparticles (BLCNs) were synthesized by the ionic gelation method, and their physicochemical characteristics and in vitro release profile were studied. The BLCNs were characterized using atomic force microscopy (AFM), FTIR spectroscopy, dynamic light scattering, and scanning electron microscopy. The BLCNs were delivered into rabbits' eyes via posterior subtenon injections. An immunohistochemical evaluation of the ocular tissues was performed, and the vitreous humor and serum bevacizumab levels were measured by ELISA. Results: Bevacizumab-loaded chitosan nanoparticles with a diameter of 80 to 380 nm were prepared and characterized. In vitro studies showed that after the first 5 days of the experiment, a significant increase in the drug release maintained the desired drug dosage for 3 weeks. Immunohistochemical in vivo studies revealed that there were BLCNs penetrating through the sclera. Furthermore, the intravitreal bevacizumab concentration reached a maximum concentration of 18 mu g/ml, and it decreased to 6 mu g/ml after only a week. Conclusion: The results revealed that subtenon injection of BLCNs is a promising alternative to intravitreal injections. In addition to the ELISA studies, immunohistochemical experiments confirmed that BLCNs enable transscleral bevacizumab penetration, and BLCN usage may provide the required bevacizumab levels for the treatment of posterior segment diseases.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111 S 292 1002]This research was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) grants 111 S 292 1002 Short Term R&D Funding Program