Effectiveness and Safety of Coadministration of Intravitreal Dexamethasone Implant and Silicone Oil Endotamponade for Proliferative Diabetic Retinopathy with Tractional Diabetic Macular Edema

Astaxanthin Ameliorates Diabetic Retinopathy in Swiss Albino Mice via Inhibitory Processes of Neuron-Specific Enolase Activity

Retinopathy is one of the most common complications of diabetes mellitus. Diabetic retinopathy (DR) occurs due to microvascular damage in retinal tissues provoked by high blood sugar levels. The available drugs for DR are limited. Astaxanthin (AST) has anti-hypertensive, anti-obesity, and anti-diabetic properties. However, the therapeutic effect of AST on DR remains elusive. The present study is designed to investigate the effects of AST on DR via inhibition of neuron-specific enolase (NSE) activity. DR was induced by the administration of streptozotocin (STZ, 35 mg/kg: intraperitoneal; and 20 μL of STZ: intravitreal) in mice. AST (10 and 20 mg/kg) was administered orally (p.o.) for 21 days. The DR associated visual changes were assessed at different time intervals via optokinetic motor response (OMR) and penta-maze (PM) tests. Blood glucose level as well as retinal catalase, lactate dehydrogenase (LDH), & neuron-specific enolase (NSE) were estimated. The reference drug i.e., dexamethasone (DEX, 10 mg/kg; p.o.) was administered for 21 days. The administration of AST showed significant ameliorative potential in DR. Hence, AST can be used as a natural medicine for the management of DR due to its potential antioxidant, anti-diabetic, and NSE inhibitory properties.

Clinical Features and Vitreous Biomarkers of Early-Onset Type 2 Diabetes Mellitus Complicated with Proliferative Diabetic Retinopathy

PURPOSE

To compare the clinical features and vitreous biomarkers of proliferative diabetic retinopathy (PDR) between patients with early-onset and late-onset type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

This case-control study analyzed the clinical data of 74 patients with PDR who underwent vitrectomy. The patients were divided into the early-onset (T2DM diagnosis age ≤ 40 years, n = 39) and late-onset (T2DM diagnosis age > 40 years, n = 35) groups. Thirty-six specimens were collected, and the liquid chip technology was used to detect the content of 27 types of cytokines in the vitreous. Differences in clinical features and cytokine levels between the two groups were evaluated. Bonferroni correction was applied for multiple comparisons.

RESULTS

Compared with the late-onset group, the levels of hemoglobin A1c (HbA1c) and total cholesterol were significantly higher in the early-onset group (P < 0.001 and P = 0.009, respectively). Patients with early-onset T2DM PDR had worse visual prognoses and a higher rate of postoperative recurrent vitreous hemorrhage. The results of cytokine detection showed that the levels of interleukin-4 (IL-4), IL-6, IL-8, IL-9, granulocyte colony-stimulating factor, interferon-γ, interferon-inducible 10 kDa, monocyte chemotactic protein 1, macrophage inflammatory protein (MIP)-1α, and MIP-1β in the early-onset group were significantly higher than those in the late-onset group (p < 0.0026). Age at diabetes diagnosis and HbA1c, IL-4, and regulated upon activation, normal T cell expressed and secreted levels were independent risk factors for visual acuity after undergoing vitrectomy.

CONCLUSION

Early-onset T2DM PDR patients had poor blood glucose and lipid metabolism, higher levels of inflammatory factors, and worse visual prognosis. Stricter metabolic management and earlier anti-inflammatory interventions may be required for patients with early-onset T2DM.

Comparison of Intraocular Cytokine Levels of Choroidal Neovascularization Secondary to Different Retinopathies

Purpose: To investigate and compare the aqueous concentrations of vascular endothelial growth factor (VEGF) and other inflammatory cytokines in various choroidal neovascularization (CNV) diseases and types.

Methods: This observational study included 127 naive eyes with CNV and 43 control eyes with cataracts. Aqueous humor (AH) samples were obtained prior to intravitreal anti-VEGF injection or cataract surgery. Multiple inflammatory cytokines, including VEGF, interleukin (IL) 6, IL-8, IL-10, interferon-inducible protein 10 (IP-10), and monocyte chemotactic protein 1 (MCP-1) levels, were measured using a multiplex bead assay. The angiogenesis index was defined as the ratio of IP-10 to MCP-1. In addition, the relationship among AH cytokine levels, central macular thickness (CMT), and CNV size on optical coherence tomography angiography (OCTA) was evaluated.

Results: Except in the myopic CNV group (P = 0.452), the AH concentration of VEGF was significantly higher in all other CNV groups than in the control group (P < 0.05 for all comparisons). IL-8, IL-10, IP-10, and MCP-1 levels (P < 0.05 for all groups) were significantly higher in all CNV diseases except those with neovascular central serous chorioretinopathy. The angiogenesis index was significantly higher in all CNV diseases (P < 0.05 for all comparisons). The VEGF level may be associated with the size of the CNV on OCTA (p = 0.043).

Conclusions: The level of intraocular inflammatory cytokines varied among different CNV diseases and CNV types. Therefore, the angiogenesis index may be a more sensitive indicator of angiogenesis.