Relationship between vascular endothelial growth factor and macular edema in retinal vein branch obstruction.

PURPOSE: Vascular endothelial growth factor (VEGF) plays an important role in branch retinal vein occlusion (BRVO) with cystoid macular edema (CME). Monitoring changes in VEGF is crucial for evaluating treatment but requires vitreous or aqueous humor sampling, which hampers its clinical application. We investigated the correlation between VEGF and protein concentration in the aqueous humor (flare) and whether this could be used to monitor treatment-related VEGF changes. DESIGN: This retrospective observational study involved 19 previously untreated patients with BRVO. Aqueous humor was obtained, and intravitreal ranibizumab (IVR) injection was administered to these patients. The correlation between VEGF and flare, central retinal thickness (CRT), and best-corrected visual acuity (BCVA) was investigated. Differences in these values were considered between pre-IVR and 1 week and 1-3 months post-IVR. Moreover, in patients with recurrence who received additional IVR, further changes in VEGF were examined. MAIN OUTCOME MEASURES: The end point of this study was BCVA, flare, and CRT at the fovea. RESULTS: Significant improvement was seen in BCVA and CRT at all time points and in Flare at 1 vs 3 months post-IVR; nevertheless, additional IVR was necessary in 94% of cases. In a patient with recurrence, CRT did not improve, even though VEGF decreased. CONCLUSION: Flare may be effective for estimating VEGF levels in aqueous humor pre-IVR. Inflammation-related molecules other than VEGF may be related to recurrence.

Effect of lipid-hydroperoxide-induced oxidative stress on vitamin E, ascorbate and glutathione in the rabbit retina.

BACKGROUND: It is possible that oxidative stress causes several retinal diseases. However, the natural biogenic role of antioxidants in the retina is not clear. PURPOSE: This study investigates the change in concentration of vitamin E (VE), ascorbate and glutathione (GSH) in the retina following vitreous injection of 600 mug 18:2 linoleic acid hydroperoxide (LHP) in male New Zealand rabbits. METHOD: LHP was injected above the retinal surface. The animals were sacrificed and the eyes enucleated before LHP injection, 1, 3, 6, 12, 24 h and 4 and 7 days after LHP injection. Retinas were removed, VE and ascorbate measured by HPLC, and GSH determined by a fluorometric method. RESULTS: The concentration of VE in the retina decreased from pretreatment levels of 154.6 +/- 29.7 nmol/g wet weight (n = 7) and was lowest at 6 h (61.1 +/- 18.1 nmol/g wet weight, n = 4, p < 0.05), then increased gradually, returning slowly to pre-LHP levels by 7 days. The concentration of ascorbate in control retinas decreased at 6 h from pretreatment levels of 7.33 +/- 0.93 micromol/g wet weight (n = 7) to 2.74 +/- 0.16 micromol/g wet weight (n = 4, p < 0.05) and returned to pretreatment levels rapidly by 24 h after injection. The concentration of GSH in retinas decreased from baseline levels of 109.53 +/- 8.19 microg/g wet weight (n = 9), was lowest at 12 h (72.40 +/- 11.17 microg/g wet weight, n = 5, p < 0.05) and returned to pretreatment levels by 7 days. CONCLUSION: The results suggest that intravitreous LHP injection is a contributor to oxidative stress in the rabbit retina by causing a reduction in antioxidant capacity.

Effects of green tea fractions on oxygen-induced retinal neovascularization in the neonatal rat.

This study aimed to investigate the preventive effects of green tea fractions (GTFs) on rat model of oxygen-induced retinopathy (OIR). Neonatal Sprague-Dawley rats were exposed to daily cycles of 80% oxygen (20.5 h), ambient air (0.5 h), and progressive return to 80% oxygen (3 h) until postnatal day 12 (P12), then the rats were placed in ambient air until P18. The green tea was fractionated by DM-A50, DM-W, M-B, and M-W. The rats were treated once daily from P6 to P17 by gastric gavage of GTFs (0.05 or 0.01 g/ml) or distilled water (DW) at 50 microl/10 g body weight. On P18, the rats were sacrificed and the retinal samples were collected. The retinal neovascularization (NV) was scored and avascular areas (AVAs) were measured as a % of total retinal area (%AVAs) in ADPase stained retinas. The NV scores in 0.01 g/ml M-W were significantly lower than those in DW. The %AVAs in 0.05 g/ml DM-A50 and in 0.05 g/ml and 0.01 g/ml M-W were significantly lower than those in DW. There were less catechins, and less caffeine in M-W fraction compared with other GTFs, suggesting components of green tea except for catechins and caffeine might suppress the neovascularization in rat model of OIR.

[The effect of Sairei-to on oxygen-induced retinal neovascularization in the neonatal rat].

PURPOSE: To study the effect of Sairei-to (ST), a Japanese traditional medicine, on oxygen-induced retinopathy (OIR) in rats. METHODS: OIR was induced by maintaining Sprague-Dawley neonatal rats in 80% oxygen for 12 days. The rats were treated once daily with oral administration of 0.75 g/kg (n = 9), 1.5 g/kg (n = 13) of ST in water, or water alone (WA, n = 13) at 5 mL/ kg body weight from day 6 to day 17. On day 18, retinal samples were collected. Retinal neovascularization (NV) was assessed by the NV score, and by the percentage of avascular area (% AVA), using a method previously reported. The number of severe retinal NV cases (NV > or = 9) was compared. The retinal vascular endothelial growth factor (VEGF) concentrations were measured with an immunoassay kit, at 0, 12, 24, 72 and 144 hours after oxygenation. RESULTS: NV score and % AVA decreased in the ST treated group compared to the WA group. However, severe NV was seen in five cases of WA and in one case of the ST treated group. Thus severe NV was inhibited significantly by ST treatment (p = 0.0185). Retinal VEGF did not differ between groups at any time points. CONCLUSION: These data suggest that severe NV in OIR is inhibited by ST treatment.