A Clinical Study Of Combined Therapy For Ischemic Central Retinal Vein Occlusion

Central retinal vein occlusion (CRVO) is one of the most frequent retinal vascular disease in causing visual loss on clinical. It is usually classified to two types, nonischemic CRVO and ischemic CRVO. The visual prognoses for patients of ischemic CRVO are extremely poor and the most common complications are persistent macular edema and neovascular glaucoma. Until now there is no effctive treatment of ischemic CRVO. In the light of clinical features of ischemic CRVO, we adept combined trerapy, includede panretinal photocogulation (PRP), pars plana vitrectomy (PPV), radial optic (RON) and intravitreal Triamcinolone Acetonide (IVTA).Purpose: This study was designed to assess the clinical effect of combined trerapy for ischemic CRVO . We used different therapy on three groups of patients to assess the effect of different doses of Triamcinolone Acetonide (TA) and PPV. And we discussed the probably machanism of combined therapy. We assessed the safety of this therapy, in order to guide for the further use on clinical.Methods: 38 eyes of 38 patients met the selection criteria were enrolled in the study, and were devided into three groups. Group 1 eyes (14 eyes of 14 patients) received PRP,PPV,RON and IVTA 2mg , Group 2 eyes (13 eyes of 13 patients) received PRP,PPV,RON and IVTA 4mg , Group 3 eyes (11 eyes of 11 patients) received PRP,RON and IVTA 4mg. The average follow-up was longer than 6 months. The major observd criteria before and after treatment included best correct visual acuity (BCVA), anterior segment and fundus examination , fundus fluorescein angiography (FFA), optical coherence tomography (OCT), multifocal electroretinogram (mfERG), primetry threshold of central 30 degree and operative complications .Results: 1 At the end of follow-up, BCVA improved in 34 eyes (89.47%), one eye (2.63%) had equal BCVA and 3 eyes (7.89%) had worse BCVA. 33eyes (86.84%) had initial BCVA worse than 0.1, finally 13 eyes (39.39%) of the 33 eyes had BCVA of 0.1 or better, 20 eyes (60.60%) had BCVA worse than 0.1; 5 eyes (13.16%) had initial BCVA of 0.1 or better, finally 4 eyes (80%) of the 5 eyes had BCVA of 0.1 or better, one eye (20%) had BCVA worse than 0.1. The BCVA at 3 day, 1,3,6 months and last visit were much better than pretreatment (p<0.05). There was a positive correlation between final and initial BCVA (p<0.01), but there was a negative correlation between final change of BCVA and initial BCVA (p<0.01). The improvement of BCVA after treatment had no statistical difference among the three groups(p>0.05). The iris neovascular of 2 eyes before treatment all regressed in two months after treatment. At the end of follow-up, no eye developed neovascular glaucoma . 2 The results of FFA show that arm-retinal circulation time and retinal circulation time at 1, 3, 6 months were significantly shorter than pretreatment. Macular edema had alleviated significantly in 34 eyes at 6 months postoperatively. All of the eyes had marked improvement of disk edema, retinal hemorrage and venous engorgement at 1 month postoperatively. 4 eyes developed chorioretinal anastomosis.3 OCT show that the central macular thickness (CMT) was significantly decreased at 1, 3 and 6 months post- operatively (p<0.01). There were negative correlations between CMT and BCVA before and after treatment (p<0.05). The reduction of CMT after treatment had no statistical difference among the three groups (p>0.05).4 mfERG show that the amplitude density of P1-wave and N1-wave at macular(1, 2ring) were significantly increased at 3 month postoperatively (p<0.01). After treatment the amplitude density of P1-wave and N1-wave at 1 ring were correlated with corresponding BCVA (p<0.05).5 The mean sensitivity, mean defect and total sensitivity at macular (central 10 degree) were significantly improved at 3 month postoperatively (p<0.01). After treatment the mean sensitivity, mean defect and total sensitivity were all correlated with corresponding BCVA (p<0.01). A visual field defect as a result of RON was not abserved.6 A well controlled hemorrage at the RON site was found in 6 eyes. 4 eyes had intraocular pressure≥21mmHg and could be controlled by local drops. 1 eye had posterior subcapsular cataracts.Conclusions: 1 Combined trerapy could sinificantly alleviate macular edema, mitigate the ischemic state and improve the visual function for patients of ischemic CRVO.2 Final visual acuity depended on the initial visual acuity. Visual acuity improved after treatment, meanwhile the morphology and fuction of macular gained improvement.3 There was no difference of curative effect by using different small dose of TA or combining PPV wether or not, but PPV could extremely accelerate the absobtion of retinal hemorrage.4 Combined therapy could sinificantly reduce the complications of IVTA.