Diabetic retinopathy (DR) is widely recognized as a neurovascular disease. Retina, being a neuronal tissue of the eye, produces neurotrophic factors for its maintenance. However, diabetes dysregulates their levels and thereby may damage the retina. Among neurotrophins, brain derived neurotrophic factor (BDNF) is the most abundant in the retina. In this study, we investigated the level of BDNF in the serum of patients with DR and also in the serum and retina of streptozotocin-induced diabetic rats. The level of BDNF was significantly decreased in the serum of proliferative diabetic retinopathy patients as compared to that of non-diabetic healthy controls (25.5 ± 8.5-10.0 ± 8.1 ng/ml, p < 0.001) as well as compared to that of diabetic patients with no retinopathy (21.8 ± 4.7-10.0 ± 8.1 ng/ml, p < 0.001), as measured by ELISA techniques. The levels of BDNF in the serum and retina of diabetic rats were also significantly reduced compared to that of non-diabetic controls (p < 0.05). In addition, the expression level of tropomyosin-related kinase B (TrkB) was significantly decreased in diabetic rat retina compared to that of non-diabetic controls as determined by Western blotting technique. Caspase-3 activity was increased in diabetic rat retina after 3 weeks of diabetes and remained elevated until 10 weeks, which negatively correlated with the level of BDNF (r = -0.544, p = 0.013). Our results indicate that reduced levels of BDNF in diabetes may cause apoptosis and neurodegeneration early in diabetic retina, which may lead to neuro-vascular damage later in DR.

PPV with JLP for optic disc pit maculopathy had similar functional and anatomic outcomes compared with vitrectomy without JLP.

The aim of this study was to measure the levels of high-mobility group box-1 (HMGB1) in the vitreous fluid from patients with proliferative diabetic retinopathy (PDR) and to correlate its levels with clinical disease activity and the levels of vascular endothelial growth factor (VEGF), the angiogenic cytokine granulocyte-colony-stimulating factor (G-CSF), the endothelial cell angiogenic markers soluble vascular endothelial-cadherin (sVE-cadherin), and soluble endoglin (sEng). Vitreous samples from 36 PDR and 21 nondiabetic patients were studied by enzyme-linked immunosorbent assay. HMGB1, VEGF, sVE-cadherin, and sEng levels were significantly higher in PDR patients than in nondiabetics (P = 0.008; <0.001; <0.001; 0.003, resp.). G-CSF was detected in only 3 PDR samples. In the whole study group, there was significant positive correlation between the levels of HMGB1, and sVE-cadherin (r = 0.378, P = 0.007). In PDR patients, there was significant negative correlation between the levels of sVE-cadherin and sEng (r = −0.517, P = 0.0005). Exploratory regression analysis identified significant associations between active PDR and high levels of VEGF (odds ratio = 76.4; 95% confidence interval = 6.32–923) and high levels of sEng (odds ratio = 6.01; 95% confidence interval = 1.25–29.0). Our findings suggest that HMGB1, VEGF, sVE-cadherin and sEng regulate the angiogenesis in PDR.

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To evaluate outcomes of temporary silicone oil (SO) tamponade in patients with complex retinal detachment. A retrospective study of 184 eyes of 177 consecutive patients who underwent SO removal (SOR) by one surgeon between 2000 and 2010. Indications for the use of SO were proliferative vitreoretinopathy (56 eyes), difficult rhegmatogenous retinal detachment (RRD) (58 eyes), diabetic traction retinal detachment (DTRD) (29 eyes), RRD due to macular hole in highly myopic eyes (16 eyes), giant retinal tears (13 eyes), and RRD after penetrating trauma (12 eyes). All eyes underwent prophylactic 360° laser retinopexy and encircling buckle at the time of primary surgery. The mean duration of SO tamponade was 47 weeks, with a mean follow-up of 66.9 weeks after SOR. Anatomical success after SOR was achieved in 96.73 %. Final visual outcome of ≥20/200 was significantly higher in eyes with RRD compared to eyes with DTRD. Young age (≤16 years), performance of pars plana lensectomy at primary procedure and presence of pseudophakia at last follow-up were factors associated with good visual outcome in eyes with RRD. Factors predicting attached retina at last follow-up were older age (>16 years), normal intraocular pressure (IOP) at initial presentation and no relaxing retinotomy performed during the primary procedure in eyes with RRD. Complications were cataract (100 %) in phakic eyes, increased IOP (15.7 %), keratopathy (3.8 %), and hypotony (2.1 %). The low redetachment rate after SOR in the present study might be due to prophylactic 360° retinopexy and use of encircling buckles at time of primary retinal reattachment.