Oxidative stress impact on growth hormone secretion in the eye

Aim To evaluate the influence of oxidative stress on extrapituitary growth hormone (GH) secretion in the eye and to analyze the interdependence between eye and serum GH levels under normal and hypoxic conditions. Methods Pars plana vitrectomy (PPV) was performed in 32 patients with developed proliferative diabetic retinopathy (PDR) and 49 non-diabetic controls, both of whom required this procedure as part of their regular treatment in the period from April 2013 to December 2014. During PPV, vitreous samples were taken and blood was simultaneously collected from the cubital vein. GH levels in serum and vitreous samples were measured by electrochemical luminescence assay. Oxidative stress was measured by enzyme- linked immunosorbent assay of advanced oxidation protein products (AOPP) and lipid hydroperoxide (LPO) in serum and vitreous. Results Serum AOPP levels were significantly higher than vitreous levels in both groups (P < 0.001 for each group) and LPO levels were significantly higher only in PDR group (P < 0.001). There was a significant positive correlation between serum and vitreous LPO levels in PDR group (r = 0.909; P < 0.001). Serum GH levels were significantly higher than vitreous levels in both groups (P < 0.001 for each group). Serum GH levels were significantly higher in PDR group than in controls (P = 0.012). Vitreous GH values were slightly higher in PDR group, but the difference was not significant. Conclusion Our study confirms that GH production in the eye is autonomous and independent of oxidative stress or pituitary GH influence

Toxoplasmotic Retinochoroiditis: Case Report and Review of the Literature

Toksoplazmotski retinokoroiditis bolest je oka uzrokovana parazitom Toxoplasma gondii. U ljudskome oku infekcija toksoplazmom najčešće se očituje kao fokalni nekrotizirajući retinitis, uz sekundarni razvoj koroiditisa koji zahvaća unutarnje slojeve mrežnice, a očituje se kao fokalna žuto-bijela lezija s okolnim edemom mrežnice i upalnim infiltratom staklovine. Te promjene, uslijed reakcije preosjetljivosti na antigen, prate različiti oblici prednjega ili stražnjega uveitisa. Lezija obično cijeli unutar razdoblja od jednoga do četiri mjeseca uz formiranje oštro ograničenoga atrofičnog ožiljka pigmentiranih rubova. Liječenje u većini slučajeva nije potrebno. Ako je potrebno, klasično liječenje sastoji se od peroralne primjene pirimetamina, sulfadiazina i folinične kiseline. U liječenju toksoplazmotskoga retinokoroiditisa makularne lokalizacije dodatno se primjenjuju kortikosteroidi s ciljem smanjenja upalne reakcije i ubrzanja oporavka vida, što je prikazano u ovome slučaju.Toxoplasmotic retinochoroiditis is a disease of the eye caused by the Toxoplasma gondii parasite. In the human eye, toxoplasma infection mostly presents itself as a focal necrotizing retinitis with secondary choroiditis, involving the inner retinal layers and appearing as a focal yellow-white lesion with surrounding retinal edema and focal vitreous infiltrate. This is followed by varying degrees of posterior and anterior uveitis due to hypersensitivity reaction of antigens. The lesion usually heals within one to four months and is replaced with a sharply demarcated atrophic scar with pigmented borders. In most cases there is no need for treatment. When treatment is necessary, classic therapy consists of oral administration of pyrimethamine, sulfadiazine, and folinic acid. In treatment of ocular toxoplasmotic retinochoroiditis that affects the macular area, additional administration of corticosteroids to diminish inflammatory reaction and hasten visual acuity recovery has its place, as it is showed in this case

Oxidathive system factor imbalance impact on vascular endothelial growth factor

Povezanost između unutarstanične hiperglikemije, promjene u oksidacijskoredukcijskoj homeostazi, pojavnost oksidativnog stresa, smanjenje antioksidativne obrane i povećano stvaranje vaskularnoga endotelnog faktora rasta (VEGF), ključni su događaji u patogenezi proliferativne dijabetičke retinopatije (PDR). Ciljevi istraživanja: 1. Utvrditi koncentracije: VEGF-a, markera oksidativnog stresa i antioksidativnog sustava u staklastom tijelu i serumu. 2. Utvrditi korelaciju tih parametara u staklastom tijelu i serumu. 3. Temeljem rezultata korelativnog odnosa mjerenih pokusnih parametara, predvidjeti mogućnost dijagnostike retinopatičnih promjena mjerenjima serumskih vrijednosti. Metode istraživanja: ispitivane varijable mjerene su u uzorcima staklastog tijela i seruma bolesnika i eksperimentalnih životinja s izraženom proliferativnom dijabetičkom retinopatijom te u istim uzorcima bolesnika i eksperimentalnih životinja bez pojavnosti oksidativnog stresa, kao kontrola. Svi parametri analizirani su standardiziranim laboratorijskim metodama, a dobivene vrijednosti statistički obrađene. Korelacije podataka između promatranih skupina prikazane su Spearmanovim koeficijentima korelacije. Rezultati su pokazali povišene markere oksidativnog stresa u oku i u sistemskoj cirkulaciji, smanjen antioksidativni kapacitet u staklastom tijelu, te povišene vrijednosti u serumu kod dijabetičara s PDR-om. Zaključak: U dijabetičara, praćenjem serumskih parametara (lipidne peroksidacije, superoksid dismutaze i VEGF-a), moguće je indirektno procjenjivati oksidativni status unutar oka, a time i nastanak/napredovanje dijabetičke retinopatije i prije nego što promjene u oku postanu klinički očite.The relationship between intracellular hyperglycemia, changes in oxidative - reductive homeostasis, the onset of oxidative stress, reduction of antioxidant defense and increased production of VEGF are considered to be key events in the pathogenesis of diabetic retinopathy. Research goals: 1. To determine concentrations of: vascular endothelial growth factor, markers of oxidative stress and antioxidant system in the vitreous humor and serum. 2. To determine the correlation between these parameters in the vitreous and serum. 3. Based on the results of the correlation of the measured experimental parameters, predict the ability to diagnose retinopathy changes based on serum values. Research Methods: The examined variables were measured in samples of vitreous and serum of patients and experimental animals with pronounced proliferative diabetic retinopathy and of control group of patients and experimental animals without incidence of oxidative stress. All parameters were analyzed by standardized laboratory methods and the obtained values were statistically evaluated. Data correlations between observed groups were presented by the Spearman correlation coefficient. Results: The results showed elevated markers of oxidative stress in the eye and systemic circulation, reduced antioxidant capacity in the vitreous humor and increased antioxidant capacity in diabetic patients with PDR. Conclusion: In diabetic patients, monitoring of serum parameters (Lipid Peroxidation, Superoxide Dismutase and VEGF), can be used to indirectly evaluate the oxidative status inside the eye, and thus the formation/progression of diabetic retinopathy before clinical manifestation of changes in the eye

Levels of selected oxidative stress markers in the vitreous and serum of diabetic retinopathy patients

PURPOSE In diabetes, an impaired antioxidant defense system contributes to the development of diabetic retinopathy. The main objective of this paper was to find correlations of oxidative stress parameters within and between the vitreous and serum in patients with type 2 diabetes who had developed proliferative diabetic retinopathy. ----- METHODS The study included and compared two groups of patients who underwent vitrectomy: 37 patients with type 2 diabetes and proliferative retinopathy (PDR), and 50 patients with non-diabetic eye disorders (NDED). Vascular endothelial growth factor (VEGF), advanced oxidized protein product (AOPP), and oxidative stress markers (direct lipid hydroperoxidation (LPO), malondialdehyde (MDA), total superoxide dismutase (SOD), and glutathione (GSH)) were measured in the vitreous and serum of both groups and correlated with one another, between humoral compartments and with gender, age, and serum glucose levels. ----- RESULTS In the vitreous of PDR patients, VEGF, LPO, and MDA (p<0.05) were increased and SOD values were slightly lowered (p<0.05) than in NDED patients. Vitreous AOPP and GSH showed no differences between the groups. In the serum, AOPP, MDA, and SOD were increased (p<0.05) and VEGF was slightly increased (p<0.05) in the PDR group compared to NDED. With regard to gender, similar changes were recorded for both groups, except for the lower serum MDA in males than females in the NDED group. Advanced age showed no significant effect on changes of measured parameters in the vitreous. In the serum, VEGF was positively correlated (p<0.05) and MDA and SOD negatively correlated (p<0.05) with increasing age. Among measured parameters within and between the vitreous and serum, several correlative links occurred in the PDR group that were not present in the NDED group. The most prominent correlation changes were between serum LPO and vitreal LPO, serum SOD and vitreal LPO, serum LPO and serum SOD, and vitreal VEGF and serum SOD. ----- CONCLUSIONS Among the selected oxidative stress markers, SOD and LPO were highly correlative in both the vitreous and serum in PDR compared to patients without metabolic disorders. Their correlations suggested that monitoring their mutual alterations might be informative during PDR development and should be considered in further research

Rituximab, Intravitreal Bevacizumab and Laser Photocoagulation for Treatment of Macrophage Activation Syndrome and Retinal Vasculitis in Lupus: A Case Report

Systemic lupus erythematosus (SLE) most commonly manifests as mild to moderate disease with severe manifestations such as diffuse alveolar hemorrhage, central nervous system vasculitis, macrophage activation syndrome (MAS) or retinal vasculitis (RV) with visual disturbances occurring in a significantly smaller proportion of patients, most of whom have a poor outcome. Macrophage activation syndrome and RV are insufficiently early and rarely recognized presentations of lupus—consequently there are still no treatment recommendations. Here we present the course of diagnosis and treatment of a patient with an SLE flare that resulted in both life-threatening disease (MAS) and vision-threatening disease (RV). The patient was successfully treated with systemic immunosuppressives, a high dose of glucocorticoids and rituximab (RTX), in parallel with intraocular therapy, intravitreal bevacizumab (BEV) and laser photocoagulation