Different Modality of Treatment in the Neovascularization of Uveitis According to Nonperfusion Area

PURPOSE: To help the treatment decision of the intraocular neovascularization(NV) in uveitis patient by analyzing the effect of different treatment modality according to extent of nonperfusion area. METHODS: The authors reviewed the uveitic patients who occured intraocular NV from Jan. 1991 to Dec. 1999 at Seoul National University Hospital. The authors divided them into two groups in regard of the size of capillary nonperfusion by fluorescein angiography ; the nonischemic group in which the area of capillary nonperfusion is less than 10 disc area, and the ischemic group in which the area is more than 10 disc area. The regression of NV between the two groups was compared according to treatment modality such as medication, laser photocoagulation and vitrectomy. RESULTS: The NV occured 32 of total 64 eyes ; the nonischemic group included 32 eyes and ischemic group 32 eyes. The medication achieved a significant reduction of NV in nonischemic group(25 of 33 eyes) compared to ischemic group(p=0.01). The laser photocoagulation achieved a significant reduction of NV in ischemic group(16 of 24 eyes) compared to nonischemic group(p=0.064). In 30 eyes with vitrectomy, the NV reduced in 23 eyes and there was no statistical difference between the two groups in reduction of NV(p=0.398). CONCLUSION: This study suggests that retinal neovascularization can be induced by both retinal ischemia and inflammation, and the inflammation plays an important part in NV in nonischemic group, whereas the retinal ischemia plays a more important part in ischemic group. Therefore, the combined treatment with laser photocoagulation can result in a better outcome in the group with large ischemic area.

Preretinal Neovascularization by Laser-induced Thrombosis in Albino Rats and Inhibition of Neovascularization by Genistein

PURPOSE: To determine the effect of genistein, an inhibitor of protein tyrosine kinase, on preretinal neovascularization through the quantification of retinal neovascularization using image analyzer in an experimental rat model. METHODS: In 36 eyes of 36 rats, retinal vein occlusion was induced by photodynamic therapy with an argon green laser and systemic injection of rose bengal (40 mg/kg). The development and progression of retinal neovascularization was followed weekly by fluorescein angiography. Seven rats were sacrificed each week, after which two eyes were prepared with H and E staining for histologic examination, and five were prepared as a control group using ADPase staining for neovascularization analysis. In the remaining fifteen eyes, retinal vein occlusion was also induced using the same method. Immediately after vein occlusion, 4.0 mg of genistein dissolved in dimethyl sulfoxide (DMSO) was injected intraperitoneally twice a day for the first 7 days. Five rats were sacrificed each week and stained with ADPase. After ADPase staining, those samples with evidence of neovascularization were quantified using an image analyzer. RESULTS: No retinal neovasularizaion was found at the end of the first week. The size of retinal neovascularization for the five eyes sacrificed at the end of week 2 and 3 were 6.53+/-2.11 mm2 and 3.77+/-3.51 mm2 in the control group, and 2.22+/-1.01 mm2 and 1.64+/-0.88 mm2 in the genistein treatment group, respectively. Retinal neovascularization was successfully suppressed until two weeks after laser treatment by genistein in this rat neovascularization model. CONCLUSIONS: Genistein may be a useful treatment modality to suppress retinal neovascularization complicated with retinal ischemic injury.