Light Emission from Fe2+-EGTA-H2O2 System Depends on the pH of the Reaction Milieu within the Range That May Occur in Cells of the Human Body.

A Fe2+-EGTA(ethylene glycol-bis (ß-aminoethyl ether)-N,N,N',N'-tetraacetic acid)-H2O2 system emits photons, and quenching this chemiluminescence can be used for determination of anti-hydroxyl radical (•OH) activity of various compounds. The generation of •OH and light emission due to oxidative damage to EGTA may depend on the buffer and pH of the reaction milieu. In this study, we evaluated the effect of pH from 6.0 to 7.4 (that may occur in human cells) stabilized with 10 mM phosphate buffer (main intracellular buffer) on a chemiluminescence signal and the ratio of this signal to noise (light emission from medium alone). The highest signal (4698 ± 583 RLU) and signal-to-noise ratio (9.7 ± 1.5) were noted for pH 6.6. Lower and higher pH caused suppression of these variables to 2696 ± 292 RLU, 4.0 ± 0.8 at pH 6.2 and to 3946 ± 558 RLU, 5.0 ± 1.5 at pH 7.4, respectively. The following processes may explain these observations: enhancement and inhibition of •OH production in lower and higher pH; formation of insoluble Fe(OH)3 at neutral and alkaline environments; augmentation of •OH production by phosphates at weakly acidic and neutral environments; and decreased regeneration of Fe2+-EGTA in an acidic environment. Fe2+-EGTA-H2O2 system in 10 mM phosphate buffer pH 6.6 seems optimal for the determination of anti-•OH activity.

Concentration Dependence of Anti- and Pro-Oxidant Activity of Polyphenols as Evaluated with a Light-Emitting Fe2+-Egta-H2O2 System.

Hydroxyl radical (•OH) scavenging and the regeneration of Fe2+ may inhibit or enhance peroxidative damage induced by a Fenton system, respectively. Plant polyphenols reveal the afore-mentioned activities, and their cumulative net effect may determine anti- or pro-oxidant actions. We investigated the influence of 17 phenolics on ultra-weak photon emission (UPE) from a modified Fenton system (92.6 µmol/L Fe2+, 185.2 µmol/L EGTA (ethylene glycol-bis(ß-aminoethyl-ether)-N,N,N',N,-tetraacetic acid) and 2.6 mmol/L H2O2 pH = 7.4). A total of 8 compounds inhibited (antioxidant effect), and 5 enhanced (pro-oxidant effect) UPE at all studied concentrations (5 to 50 µmol/L). A total of 4 compounds altered their activity from pro- to antioxidant (or vice versa) along with increasing concentrations. A total of 3 the most active of those (ferulic acid, chlorogenic acid and cyanidin 3-O-glucoside; mean UPE enhancement by 63%, 5% and 445% at 5 µmol/L; mean UPE inhibition by 28%, 94% and 24% at 50 µmol/L, respectively) contained catechol or methoxyphenol structures that are associated with effective •OH scavenging and Fe2+ regeneration. Most likely, these structures can determine the bidirectional, concentration-dependent activity of some phenolics under stable in vitro conditions. This is because the concentrations of the studied compounds are close to those occurring in human fluids, and this phenomenon should be considered in the case of dietary supplementation with isolated phenolics.

Effect of Physiological Concentrations of Vitamin C on the Inhibitation of Hydroxyl Radical Induced Light Emission from Fe2+-EGTA-H2O2 and Fe3+-EGTA-H2O2 Systems In Vitro.

Ascorbic acid (AA) has antioxidant properties. However, in the presence of Fe2+/Fe3+ ions and H2O2, it may behave as a pro-oxidant by accelerating and enhancing the formation of hydroxyl radicals (•OH). Therefore, in this study we evaluated the effect of AA at concentrations of 1 to 200 µmol/L on •OH-induced light emission (at a pH of 7.4 and temperature of 37 °C) from 92.6 µmol/L Fe2+-185.2 µmol/L EGTA (ethylene glycol-bis (ß-aminoethyl ether)-N,N,N',N'-tetraacetic acid)-2.6 mmol/L H2O2, and 92.6 µmol/L Fe3+-185.2 µmol/L EGTA-2.6 mmol/L H2O2 systems. Dehydroascorbic acid (DHAA) at the same range of concentrations served as the reference compound. Light emission was measured with multitube luminometer (AutoLumat Plus LB 953) for 120 s after automatic injection of H2O2. AA at concentrations of 1 to 50 µmol/L and of 1 to 75 µmol/L completely inhibited light emission from Fe2+-EGTA-H2O2 and Fe3+-EGTA-H2O2, respectively. Concentrations of 100 and 200 µmol/L did not affect chemiluminescence of Fe3+-EGTA-H2O2 but tended to increase light emission from Fe2+-EGTA-H2O2. DHAA at concentrations of 1 to 100 µmol/L had no effect on chemiluminescence of both systems. These results indicate that AA at physiological concentrations exhibits strong antioxidant activity in the presence of chelated iron and H2O2.

Light emission from the Fe2+ -EDTA-ascorbic acid-H2 O2 system strongly enhanced by plant phenolic acids.

Oxidative reactions can result in the formation of electronically excited species that undergo radiative decay depending on electronic transition from the excited state to the ground state with subsequent ultra-weak photon emission (UPE). We investigated the UPE from the Fe2+ -EDTA (ethylenediaminetetraacetic acid)-AA (ascorbic acid)-H2 O2 (hydrogen peroxide) system with a multitube luminometer (Peltier-cooled photon counter, spectral range 380-630 nm). The UPE, of 92.6 µmol/L Fe2+ , 185.2 µmol/L EDTA, 472 µmol/L AA, 2.6 mmol/L H2 O2 , reached 1217 ± 118 relative light units during 2 min measurement and was about two times higher (P < 0.001) than the UPE of incomplete systems (Fe2+ -AA-H2 O2 , Fe2+ -EDTA-H2 O2 , AA-H2 O2 ) and medium alone. Substitution of Fe2+ with Cr2+ , Co2+ , Mn2+ or Cu2+ as well as of EDTA with EGTA (ethylene glycol-bis(ß-aminoethyl ether)-N,N,N',N'-tetraacetic acid) or citrate powerfully inhibited UPE. Experiments with scavengers of reactive oxygen species (dimethyl sulfoxide, mannitol, sodium azide, superoxide dismutase) revealed the dependence of UPE only on hydroxyl radicals. Dimethyl sulfoxide at the concentration of 0.74 mmol/L inhibited UPE by 79 ± 4%. Plant phenolics (ferulic, chlorogenic and caffec acids) at the concentration of 870 µmol/L strongly enhanced UPE by 5-, 13.9- and 46.8-times (P < 0.001), respectively. It is suggested that augmentation of UPE from Fe2+ -EDTA-AA-H2 O2 system can be applied for detection of these phytochemicals.

Light Emission from the Fe2+-EGTA-H2O2 System: Possible Application for the Determination of Antioxidant Activity of Plant Phenolics.

Oxidative reactions can result in the formation of electronically excited species that undergo radiative decay depending on electronic transition from the excited state to the ground state with subsequent ultra-weak photon emission (UPE). We investigated the UPE from the Fe2+-EGTA (ethylene glycol-bis(ß-aminoethyl ether)-N,N,N',N'-tetraacetic acid)-H2O2 system with a multitube luminometer (Peltier-cooled photon counter, spectral range 380 to 630 nm). The UPE of 92.6 µmol/L Fe2+-185.2 µmol/L EGTA-2.6 mmol/L H2O2 reached 4319 ± 755 relative light units during 2 min measurement and was about seven times higher (p < 0.001) than the UPE of incomplete systems (Fe2+-H2O2, EGTA-H2O2) and medium alone. Substitution of Fe2+ with Cr2+, Co2+, Mn2+ or Cu2+ as well as of EGTA with EDTA (ethylenediaminetetraacetic acid) or citrate completely abolished UPE. Experiments with ROS scavengers revealed the dependence of UPE on hydroxyl radicals suggesting occurrence of oxidative attack and cleavage of the ether bond in EGTA backbone structure and formation of triplet excited carbonyl groups with subsequent light emission. Plant phenolics (ferulic, chlorogenic and caffec acids) at concentration 87 µmol/L and ascorbate at 0.46 mmol/L inhibited UPE by 90 ± 4%, 90 ± 5%, 97 ± 2% and 92 ± 1%, respectively. Quenching of UPE from Fe2+-EGTA-H2O2 system can be used for evaluation of antioxidant activity of phytochemicals.

Bone metabolism assessment, bone metabolism index designation and the determination of its normal values range in young healthy women.

BACKGROUND: Bone metabolism assessment requires the determination of bone mass and quality. The bone metabolism was assessed with the modified bone scintigraphy using 99mTc-MDP. The elaboration of radioisotopic method and program allowed for the assessment of bone metabolism, index of bone metabolism assay and definition of its normal values range with the possibility of clinical application. MATERIAL/METHODS: We examined 70 healthy young women with normal BMI, in which bone system was assessed with scintigraphic and densitometric examinations, and bone turnover markers definition together with hormonal and biochemical blood tests were performed. Group exclusion examinations were also performed, including basic, biochemical and hormonal blood tests, bone turnover markers and densitometric examinations with DXA technique. The scintigraphic examinations were performed using a gamma camera after 99mTc-MDP injection. After the application of the BONS method and program, the normal values range was determined with the STATISTICA 8 program. RESULTS: The normal results of basic, biochemical, hormonal and vascular tests were obtained. The examinations of bone turnover markers confirmed the balance between bone formation and bone resorption processes. The normal results of densitometric examinations excluded osteopeny or osteoporosis. The normal values range of IBM in young healthy women was between 84.08 and 105. CONCLUSIONS: The elaborated BONS program and method allow for the quantitative assessment of bone quality and definition of IBM normal values range. The quantitative scintigraphic bone examinations provide an alternative to the bone markers examination for obtaining information about bone metabolism.

Influence of pharmacological treatment on blood flow and muscle perfusion in patients with obliterative atheromatosis assessed with isotopic methods. A pilot study.

BACKGROUND: Most of the methods don't give the comparison between blood flow at rest and after exercise. Nuclear medicine allows for such assessment and determination of muscle perfusion indexes. The aim of the study was the comparison of the radioisotopic assessment of lower limbs perfusion at rest and after exercise in patients with obliterative atheromatosis subjected to combined treatment with the standard vascular examinations. MATERIAL/METHODS: 35 patients with stage II according to Fontaine and claudication distance 30-500 m, subjected to the combined medical treatment were included to the study. Basic examinations, claudication distance measurements, standard vascular examinations, and radioisotopic examinations of lower limbs perfusion with Tc99mMIBI were performed in all patients. RESULTS: After 6 months of therapy the results of perfusion scintigraphy showed that combined pharmacological treatment caused the significant improvement of calf perfusion at rest (p<0.05), which justifies its application in chronic ischemia of lower limbs. Such improvement was not observed while analyzing the results of standard vascular indexes. CONCLUSIONS: The use of perfusion scintigraphy allows for precise definition of the state of the limbs perfusion and shows the improvement of lower limbs perfusion at rest after medical treatment. It is a more precise and sensitive examination, gives more information comparing to the standard vascular examinations, and completes standard vascular diagnostics in patients with obliterative atheromatosis.

The behaviour of bone mineral density and bone metabolism index in young and menopausal women with the consideration of body mass index.

BACKGROUND: The bone fractures in patients with osteopeny have broaden the risk factors by body mass index (BMI) and bone metabolism assessment defined with bone scintigraphy. The aim of the study was to evaluate the behavior of bone mineral density (BMD) and bone metabolism index (IBM) in both young women and those more than 50 years old, as associated with BMI. MATERIAL/METHODS: BMD and IBM were assessed in young women (group 1; n=66) and those after 50 (group II; n=67) with the allowance for BMI (< or =25 kg/cm(2) and >25 kg/cm(2)). Detailed densitometric and radioisotopic examinations were performed in all patients. The results of BMI, IBM and BMD were compared. RESULTS: In women with BMI >25, IBM was insignificantly lower than in women with BMI <25, independent of age (p>0.05). Comparing with the women with normal BMI, there was a slight increase of femoral bone neck and the whole skeleton BMD, thus IBM was insignificantly lower (p>0.05). A powerful positive correlation was observed between IBM and BMD of femoral bone neck and the whole skeleton. With BMI <25, there was a weak positive correlation of BMI and IBM. In young women with BMI >25 there was a powerful positive correlation of BMD and IBM. CONCLUSIONS: Independently of BMI, together with age increase, BMD was lower, yet, the dependency between BMI and BMD was increasing. We showed a strong statistical dependency between BMD and IBM.

Referral to radioisotope examination as a source of additional radiation exposure for staff.

BACKGROUND: Every exposure of human to ionizing radiation increases the likelihood of deterministic sequelae. At the same time, it is associated with the risk of stochastic effects. Consequently, this can lead to cancer, mainly of the hematopoietic system. Organs or tissues show a different affinity for gamma radiation. There are many technical and organizational measures which minimize the impact of this radiation on people and especially on the staff of the nuclear medicine laboratory. MATERIALS AND METHODS: The study was based on 208 referrals to the scintigraphic laboratory, which were executed between 26.09.2018 and 13.11.2018 in the Department of Nuclear Medicine of Military Medical Academy Memorial Teaching Hospital of the Medical University of Lodz - Central Veterans` Hospital. Referrals concerned scintigraphic tests of bones, salivary glands, parathyroid glands, myocardial perfusion, somatostatin receptor analogues, renoscintigraphic and lymphoscintigraphic tests. In case of each referral, radiation power was measured at a distance of approx. 10 cm with the use of a calibrated Geiger-Muller detector. Measurements were performed immediately after the end of the last examination each day. Daily measurement of the background radiation dose was also a standard procedure. For calculations, this value was averaged to 0.18µSv/h. Based on the above measurements, a statistical analysis of all data was performed. Obtained data was also analysed after it was ascribed to the person complexing radiopharmaceuticals on a given day. The annual dose for a radiopharmacist is 0.12 mSv, for a technician 0.35 mSv and for a doctor 0.45 mSv. RESULTS: The average radiation dose received every working day by the staff was 11.49 µSv/h. After considering the average distance from the potential source of exposure (50 cm), this power decreased to 0.46µSv/h. In order to calculate the quarterly and annual radiation dose, it was assumed that the employee worked 250 days a year. CONCLUSIONS: Medical records may pose an additional personnel exposure to ionizing radiation. Physicians are the most vulnerable group of employees. The way of radiopharmacists work contributes to the contamination of medical records.

The assessment of testosterone and radioisotopic index of bone metabolism and bone mineral density in men with testosterone deficiency after one year of testosterone therapy.

BACKGROUND: Testosterone deficiency in men is characterized by typical symptoms of hypogonadism and negative influence on the preservation of bone mass. In this study, we analysed the relationship between testosterone concentration and bone metabolism. Moreover, we assessed the impact of one-year compensation of testosterone deficiency in elderly men on bone metabolism and bone mineral density. Radioisotopic methods of bone metabolism assessment provide new research opportunities. MATERIALS AND METHODS: Men with total testosterone concentration (TT) ≤ 3 ng/ml were included into this study. Patients with disorders or injuries of bone system, elevated prostate-specific antigen (PSA), enlarged prostate, disorders of thyroid and liver, diabetes mellitus or a history of chemotherapy as well as those treated for a long time with antibiotics were excluded from this study. The results of 50 men aged 57.52 ± 6.71 years obtained before the treatment (I test) and after one year of oral testosterone supplementation (test II) were analysed in this study. The following examinations and analyses were performed: interview and physical examination, orthopaedic, neurological and urological consultations, blood biochemistry, determination of hormones levels, assessment of Testosterone Deficiency Syndrome (TDS), densitometric and radioisotope assessment of bone metabolism. Moreover, radioisotopic index of bone metabolism was calculated. Testosterone therapy with oral preparation Undestor Testo Caps (Organon) containing 40 mg of testosterone lasted for 12 months. Statistical analysis was performed using Statistica 12 and Excel 2010 programs. Correlations between results before and after treatment were analysed. RESULTS: After 12 months of treatment, testosterone concentration increased by mean 78% and the level of luteinizing hormone (LH) decreased by 62%. TDS index increased from 0.53 ± 0.21 (in test I) to 1.91 ± 0.60 (in test II). After the therapy this index was significantly higher in all men (p < 0.0001). Moreover, BMD was also improved following therapy, however, the difference between test I and II was statistically insignificant. The greatest change was found in case of IBM (Index of Bone Metabolism). We observed a positive correlation between IBM and BMD before treatment (r = 0.7991), however, its strength decreased after one-year therapy (r = 0.6757). CONCLUSIONS: In our opinion, IBM is more sensitive than other methods of the assessment of changes occurring in bone system under the influence of testosterone therapy. The observed changes in IBM were proportional to changes in testosterone concentration. Testosterone level, TDS and radioisotopic assessment of bone metabolism may be used as prognostic and therapeutic factors of osteoporosis and bone fractures in elderly men.

Radioisotopic assessment of bone metabolism of the operated vertebra after inter-process stabilizer implantation in the lumbar segment of the spine.

INTRODUCTION: Lack of efficacy of pharmacotherapy and physiotherapy in spinal pain syndrome is an indication for intervertebral stabilizer implantation between the processes in the lumbar segment of the spine. MATERIAL AND METHODS: The group consisted of 32 patients qualified after radioisotopic single-photon emission computed tomography/computed tomography (SPECT/CT) examinations with assessment of bone metabolism and mineral density. For comparative purposes, the L2 vertebra was defined as normal. Parameters defined in the area of operated vertebrae were comparable to L2. Imaging examinations and a pain intensity test were performed before and 12 months after the procedure. RESULTS: In SPECT, osteotropic isotope (OI) activity in spinous bodies and processes was close to L2 values. Density assessed in CT of analysed vertebrae was close to L2. In the control examination, activity of OI in spinous bodies and processes was higher in the procedure area. Under the stabilizer, there was a strong positive correlation with the L2 parameters. The differences were statistically significant (p = 0.0002). The increase of OI activity in the elements above the stabilizer was variable. In the control examination, there was higher density of spinous processes and bodies above and under the stabilizer. The difference, compared to the L2 density, was statistically significant. CONCLUSIONS: The radioisotopic method with SPECT/CT allows for the precise assessment of bone metabolism in the spine. After the procedure, a negative correlation was observed between bone metabolism changes and pain intensity test results.

The own method and program of isotope quantitatively assessment of perfusion in muscles of upper limbs (initial report).

BACKGROUND: The issue of blood flow in muscles has been dealt with for many years. However, most often it was assessed qualitatively with standard vascular examinations. The quantitatively perfusion assessment is indispensable in the normal and pathological conditions. Some diseases impair the perfusion mainly in the area of upper limbs. It can be observed in Raynaud's disease, vascular occlusive diseases, neurological disturbances, and thermal injuries. Hyperhidrosis of upper limbs after sympathectomy of thoracic part of sympathetic trunk may bring closer the diagnosis statement. Nuclear medicine has the markers and methods that allow for the assessment of the volume of perfusion in muscles. The aim for creating this method and program was the development of radioisotope method allowing for quantitative assessment of perfusion in muscles of upper limbs. This should lead to calculating the perfusion index and its range of normal values in a greater group of patients and to using this method both in the healthy and pathological conditions. MATERIAL AND METHODS: 20 patients, age 30.4 ± 7.1 years, who underwent following examinations: qualification to the group, medical history, subject examinations, USG of upper limb vessels, anthropometric examinations, biochemical and hormonal blood tests, the assessment of upper limbs with USG Doppler and FMD (flow mediated dilatation), radioisotope examinations with gamma camera BrightView XCT by own program RAPUL (Radioisotope Assessment Perfusion of Upper Limb). Acquisitions were started five minutes after intravenous injection of 99mTc-MIBI (metoxyisobutylnitrite). The whole body scintigram and scintigrams of arm and forearm muscles in A-P projections were taken. RESULTS: In the examined patients, the results of anthropometric, biochemical and hormonal test were within the range of normal values. In radioisotope quantitative assessment of perfusion, perfusion indexes of left arm were 20 < PI(_left) < 11.90 and of the right arm 7.00 < PI(_right) <12.30. The dependency correlation PI(_left) vs. PI(_right) was strong r = 0.92036.The values of perfusion symmetry index (IPS) had a normal distribution and were within the following range: 0.9231 < IPS < 1.1019. CONCLUSIONS: The RAPUL method and program allow for quantitative assessment of perfusion in muscles of upper limbs. Developed program has a high repeatability of results. The results in the bigger group will allow for defining the range of normal values of perfusion index in muscles of upper limbs at rest. These will be diagnostically used both in healthy (sports medicine, military services) and pathological conditions.

Reliability of different radioisotopic techniques in diagnosing solitary hot spots in the spine of patients with malignant neoplasm.

INTRODUCTION: Early diagnosis of spinal metastases is of key importance in further therapeutic management. OBJECTIVES: The aim of the study was to assess the reliability of single-photon emission computed tomography (SPECT) or SPECT and computed tomography (SPECT/CT) in the diagnosis of solitary hot nodules in the spine identified by scintigraphy. PATIENTS AND METHODS: In this retrospective study, 70 patients with neoplastic disease and a solitary nodule detected in the spine were analyzed. Using a SPECT/CT γ-camera, the type and site of the foci in the vertebra were analyzed. Bone scintigraphy, SPECT, and CT were performed. Reliability of the results was assessed depending on the applied technique. RESULTS: In malignant lesions, increased isotope uptake was observed in the vertebral body with the posterior arch (89%), the body and both arches (67%), and the body alone (14%). In benign lesions, increased uptake was observed in the body area or in the joint area. Using SPECT, 25 of 27 cases (93%) of foci were properly classified as malignant. Using SPECT/CT, malignant lesions were observed in 26 of 27 cases (96%). Using SPECT, 19 of 43 cases were identified as benign (44%), and using SPECT/CT, 31 of 43 were identified as benign (72%). The agreement between SPECT and SPECT/CT was higher for malignant lesions (89%) than for benign lesions (67%). The use of CT in SPECT/CT examinations allowed to change the SPECT diagnosis of malignant lesions to that of benign lesions in 50% of the cases. CONCLUSIONS: The criteria used in the diagnosis of solitary nodules in the spine direct the diagnosis largely towards noncancerous lesions. Reliability of positive assessment was significantly lower than that of negative one - 51% in SPECT and 68% in SPECT/CT. A hybrid SPECT/CT camera is more reliable than SPECT alone in the assessment of spinal lesions.

Correlation of the severity of diabetic retinopathy and the heart muscle perfusion in patients with type 2 diabetes.

OBJECTIVE: The objective was to investigate whether microvascular disturbances in patients with type 2 diabetes (DM) as defined by retinal examination predict the existence of macrovascular disturbances found on radioisotopic perfusion examinations of the heart muscle. MATERIALS AND METHODS: A total of 100 patients with type 2 DM and an additional cardiovascular risk factor were enrolled in the study. All patients underwent comprehensive ophthalmologic examination, including fundus color photography and fluorescein angiography, and were divided into three groups: group 1 (NoDR): met the inclusion criteria but had no diabetic retinopathy; group 2 (NPDR): had signs of nonproliferative diabetic retinopathy; group 3 (PDR): had signs of preproliferative or proliferative diabetic retinopathy. After collecting general medical history and clinical data, patients underwent heart muscle perfusion studies. All patients followed a 48-h protocol heart muscle perfusion examination in the rest state as well as after the standardized exercise test. Single photon emission computed tomography examination was performed. RESULTS: In the PDR group, the impairment of the heart muscle perfusion at stress and rest was more frequent than in the NPDR and NoDR groups. Analysis of the heart muscle perfusion results for the three groups showed a significant relationship with the severity of microvascular complications observed in eye fundus examinations. CONCLUSIONS: Comprehensive ophthalmologic assessment of the progression of diabetic retinopathy in patients with type 2 DM may be an indicator of heart muscle perfusion disturbance.

Progression of diabetic retinopathy correlated with muscle perfusion disturbances of the lower limbs, with clinically important diagnostic recommendations.

INTRODUCTION: The objective of this study was to investigate the relationship between microvascular and macrovascular disturbances in patients with type 2 diabetes, as shown by results of ophthalmological examination and by vascular and perfusion examinations of the lower limbs. MATERIAL AND METHODS: A total of 85 patients with type 2 diabetes and an additional cardiovascular risk factor were enrolled in the study. All patients underwent complex ophthalmological examination, including fundus colour photography and fluorescein angiography, and were divided into two groups: group I with signs of diabetic non-proliferative retinopathy (NPDR), and group II with signs of diabetic proliferative retinopathy (P/PDR). After collection of the general medical history and analysis of medical data, patients underwent vascular and muscle perfusion examination of the lower limbs. RESULTS: In the P/PDR group, disturbances of lower-limb perfusion were more frequent than in the NPDR group. Analysis of the blood flow and results of lower-limb muscle perfusion for the two groups showed a significant relationship with the severity of microvascular complications observed in examination of the fundus. CONCLUSIONS: Ophthalmological assessment of the progression of diabetic retinopathy in patients with type 2 diabetes is a reliable indicator of the changes in peripheral vessel systems and perfusion defects in the lower limbs.