Mitsumasa Wada

Plasma levels of vascular endothelial growth factor and pigment epithelium-derived factor before and after intravitreal injection of bevacizumab

Aims To determine the level of vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) in the plasma of patients with proliferative diabetic retinopathy before and after an intravitreal injection of bevacizumab. Methods Eleven patients with type 2 diabetes and control of 30 non-diabetic patients were studied. The 11 eyes of 11 patients received an injection of bevacizumab (1.25 mg). Samples of blood were collected just before the injection, and after 1 day, 7 days and 1 month. The concentrations of VEGF and PEDF in the plasma were measured by ELISA. Results The VEGF concentration before the injection was 114.0 pg/ml. It was significantly reduced to 9.7 pg/ml after 1 day, to 11.7 pg/ml after 7 days and to 25.9 pg/ml even after 1 month (p<0.001, p<0.001, p<0.001, respectively). The PEDF concentration before the injection was 7.2 μg/ml. It was significantly reduced to 5.8 μg/ml after 1 day, to 5.8 μg/ml after 7 days and to 6.3 μg/ml after 1 month (p<0.001, p<0.001, p>0.05, respectively). Conclusions The decreased levels of blood VEGF after an intravitreal injection of bevacizumab indicate that bevacizumab enters the general circulation and may also affect the PEDF levels. Thus, we should carefully examine patients for systemic changes and the fellow eye after an intravitreal injection of bevacizumab.

Effects of Intravitreally Injected Bevacizumab on Vascular Endothelial Growth Factor in Fellow Eyes

PURPOSE Whether an intravitreal injection of bevacizumab in 1 eye will have any effect on the fellow eye has been discussed. The aim of this study was to determine the level of vascular endothelial growth factor (VEGF) in the fellow eyes after an intravitreal injection of bevacizumab in 1 eye with proliferative diabetic retinopathy. METHODS Eight patients who had similar findings of proliferative diabetic retinopathy in both eyes were studied. Four patients had rubeosis (rubeosis group), and 4 patients did not have rubeosis (no-rubeosis group) in the anterior chamber. All patients received an intravitreal injection of bevacizumab (1.25 mg) in 1 eye. Samples of aqueous humor were collected from the injected eyes just before the injection of bevacizumab and 1 day after the first injection just before vitrectomy. Samples of aqueous humor from the fellow eyes were collected just before a second injection of bevacizumab in the fellow eye at 7 days after the first injection. The concentration of VEGF in the aqueous humor was measured by enzyme-linked immunosorbent assay. RESULTS After 1 day, the concentration of VEGF in injected eyes was significantly reduced from 3,230.3±2,136.8 to 3.1±3.6 pg/mL (P<0.05) in eyes with rubeosis and 465.0±78.8 to 0 pg/mL (P<0.05) in those without rubeosis. After 7 days, the VEGF level of the fellow eyes was still significantly lower than that in the injected eye just before the injection of bevacizumab (688.5±443.1 pg/mL) in the rubeosis group, and it was 7.8±13.2 pg/mL in the no-rubeosis group (P<0.05). CONCLUSIONS A single intravitreal injection of bevacizumab significantly reduced the VEGF concentrations in the aqueous humor of the fellow untreated eye. Thus, we need to be observant of the fellow eyes after a unilateral injection and also examine the patients for systemic changes.

Pars Plana Vitrectomy with Removal of Posterior Hyaloid Face in Treatment of Refractory Diabetic Macular Edema Resistant to Triamcinolone Acetonide

BackgroundTriamcinolone acetonide (TA) has recently been used to treat diabetic macular edema (DME) but its effectiveness is limited.CasesThree patients (three eyes) with unresolved diffuse DME who did not respond to a posterior sub-Tenons injection of TA underwent vitrectomy.ObservationsIntraoperatively, it was found that all of the eyes had a posterior hyaloid face that was adherent to a large area of the posterior pole retina, although this had not been detected by slit-lamp biomicroscopy or optical coherence tomography. After vitrectomy and removal of the posterior hyaloid face, there was a significant reduction in the central macular thickness of all three eyes and an improvement in the visual acuity of the patients.ConclusionsWhen TA treatment is not effective for DME, vitrectomy with the complete removal of the posterior hyaloid face, including removal of the internal limiting membrane, should be considered.

Trans-Tenon's retrobulbar injection of triamcinolone acetonide for diffuse diabetic macular edema

PurposeTo determine whether a trans-Tenons retrobulbar injection of triamcinolone acetonide (TA) is a safe and effective treatment for diffuse diabetic macular edema.MethodsThirty-nine eyes of 30 diabetic patients with persistent macular edema were treated with 20 mg of TA injection. Central macular thickness (CMT) determined by optical coherence tomography (OCT) and visual acuity were evaluated before the injection and at 1, 2, 3, and 6 months, and up to 1 year in some eyes, after the injection.ResultsThe CMT decreased significantly from 478 ± 129 µm (mean ± SD) before injection to 316 ± 102 µm at 1 month, 307 ± 104 µm at 2 months, and 275 ± 89 µm at 3 months after a single injection of TA. A 20% reduction of CMT from the initial value was maintained by a single injection of TA in 27 of 39 eyes (69.2%) at 3 months, in 14 of 22 eyes (63.6%) at 6 months, and in 5 of 7 eyes at 12 months. A recurrence of macular edema was observed in 10% of the eyes at 3 months, and in 22.7% at 6 months. The 17 eyes in which vitrectomy had been carried out had a more significant improvement in CMT than the eyes without vitrectomy.ConclusionA 20-mg trans-Tenons retrobulbar TA injection is a safe and effective treatment for diabetic macular edema. Jpn J Ophthalmol 2005;49:509–515

Senescence in cultured trabecular meshwork cells

Background: It has been suggested that replicative senescence might be involved in the pathophysiology of age-related diseases. Aim: To study the process of senescence in trabecular meshwork (TM) cells. Methods: Porcine TM tissues were obtained and placed in primary cultures with Dulbecco’s modified Eagle’s medium/Ham’s F-12 medium. After 2–3 weeks, migrated and proliferated TM cells were trypsinised and cultured in serial passages, and identified with fluorescein-labelled low-density lipoprotein (DiI-Ac-LDL), a marker of TM cells. Staining for senescence-related β-galactosidase activity was performed at population doubling level (PDL) 2, 8 and 16 at pH 6. Terminal restriction fragment (TRF) length was examined by Southern blot analysis using a 32P-labelled telomere-specific sequence (TTAGGG)3 at each PDL. Results: DiI-Ac-LDL staining revealed that most (nearly 100%) of the cells in the culture were TM cells, which were flattened in shape and positive for senescence-related β-galactosidase staining at PDL 16. Reduction of TRF length as a function of population doubling was also shown. Conclusions: TM cells exhibited characteristics of senescence at PDL 16 in vitro. The results demonstrated that cellular senescence may be related to the pathophysiology of primary open-angle glaucoma.

Characteristics of age-related macular degeneration in patients with diabetic retinopathy

PurposeThe purpose of this study was to determine the clinical characteristics of age-related macular degeneration (AMD) in patients with diabetic retinopathy (DR).MethodsRetrospective, consecutive case series. Twenty-six eyes of 25 Japanese patients were studied. All patients were diagnosed as having exudative AMD with DR. Patients with no apparent DR, dry AMD, neovascular maculopathy associated with high myopia, and age <50 years were excluded. The clinical characteristics of AMD in patients with DR, e.g., gender, age, stage of DR, and type of AMD were evaluated.ResultsIn the 26 eyes, 2 eyes (7.7%) were classified as mild nonproliferative DR (NPDR), 7 (27.0%) with moderate NPDR, 16 (61.5%) with severe NPDR and 1 eye (3.8%) with PDR. Of the 26 eyes with exudative AMD, 21 eyes (80.8%) were classified as neovascular AMD, 4 (15.4%) as polypoidal choroidal vasculopathy and 1 eye (3.8%) as a retinal angiomatous proliferation. Among the eyes with neovascular AMD, 9 eyes (42.9%) were classified as predominantly classic choroidal neovascularization (CNV).ConclusionsThere is a predominance of men, neovascular AMD and predominantly classic CNV in Japanese AMD patients with DR. The exudative AMD in patients with DR may have different clinical characteristics from those without DR.

Vascular Endothelial Growth Factor Promotes Experimental Choroidal Neovascularization in Monkey Eyes

PURPOSE To evaluate the effect of vascular endothelial growth factor (VEGF) on experimental choroidal neovascularization (CNV) in monkey eyes through clinical, morphometric, and histological observations. METHOD CNV was induced in both eyes of 6 rhesus monkeys by intense photocoagulation by red krypton laser. Immediately after photocoagulation, 2.5 micrograms of exogenous human VEGF was injected into the vitreous of the left eye in each animal. The right eyes served as controls. The eyes were enucleated 3 days to 12 weeks after photocoagulation and were examined by light and electron microscopy. RESULTS VEGF-treated eyes developed remarkable serous retinal detachment around the sites of photocoagulation with manifest CNV one week after photocoagulation. Although there was no difference in the incidence of CNV between the treated and control eyes, the treated eyes showed more intense leakage of fluorescein from the CNVs for up to 4 weeks after treatment. Morphometrically, the CNVs were significantly larger and continued to grow longer in the treated than in the control eyes after one week of photocoagulation. Histologically, newly formed vessels with a distinct lumen were present in the treated eyes after 3 days of photocoagulation. CONCLUSION Intravitreal injection of human VEGF promotes experimental choroidal neovascularization in monkey eyes.