Clinical Curative Effects Observation Of Combined Therapy For Ischemic Central Retinal Vein Occlusion

Central retinal vein occlusion (CRVO) is a kind of common retinalvascular disease causing vision loss clinically. It is classified to two types,one is nonischemic CRVO (or incomplete blockage) and another isischemic CRVO (or complete blockage). Comparing with nonischemicCRVO, the patients of ischemic CRVO will face a high probability ofpersistent macular edema and neovascular glaucoma (NVG), worseprognosis in vision. How to treat ischemic CRVO effectively, avoid theoccurrence of NVG and improve the patients’ vision? It is a topic wehave paid much attention to. According to the clinical characters ofischemic CRVO, this study applies a kind of combined therapy, includingpars plana vitrectomy (PPV), internal limiting membrane peeling (ILMpeeling), panretinal photocoagulation (PRP), radial optic neurotomy(RON) and intravitreal Triamcinolone Acetonide (IVTA).Purpose: Evaluating the clinical effectiveness of RON between twogroups of ischemic patients treated with different therapies, and deeplystudying the mechanism and curative effect of combined therapy, in orderto direct the application of combined therapy clinically.Methods:24eyes of24patients conforming the criteria of ischemicCRVO were divided into two groups, group one (12eyes of12patients)and group two (12eyes of12patients). Group one received Phaco+IOL,PPV, ILM peeling, PRP, RON and IVTA4mg and group two receivedPhaco+IOL, PPV, ILM peeling, PRP and IVTA4mg. After treatment,follow-up would last for more than six months. Before and after treatment,the main observed indicators are including best correct visual acuity(BCVA), intraocular pressure, anterior segment and fundus examination,optical coherence tomography (OCT), fundus fluorescein angiography (FFA), multifocal electroretinogram (mfERG), perimetry threshold ofcentral30degree and operative complications.Results:1. The BCVA of24eyes in two groups increased significantly in one,three and six months after treatment, there was statistically significantdifferences comparing with before treatment (P<0.01). The BCVA aftersix months treatment has a significant positive correlation with initialBCVA (r=0.601, P<0.01). The incremental value of BCVA after treatmenthas a significant negative correlation with initial BCVA (r=-0.819,P<0.01). There was no statistically difference between group one andgroup two on incremental value of BCVA (P>0.05).2. OCT showed that the central macular thickness (CMT) wassignificantly decreased at one, three and six months after treatment, therewas statistically significant differences comparing with before treatment(P<0.01). Before treatment, CMT had a negative correlation with relativeBCVA (r=-0.414, P<0.05). However, there was no correlation betweenCMT and relative BCVA after one, three and six months’ treatment. Andno statistically differences existed between group one and group two afterone, three and six months’ treatment (P>0.05).3. FFA showed that both arm-retinal circulation time and retinalcirculation time at one and three months were significantly shorten, andstatistically significant differences were existed comparing withpretreatment (P<0.01). There was no statistically differences ofarm-retinal circulation time and retinal circulation time between groupone and group two (P>0.05). All of the24eyes had significant alleviationof macular edema, disk edema, and significant improvement of retinalhemorrage and venous engorgement after one month treatment.50daysafter treatment, one eye had formed chorioretinal anastomosis in the RONregion.4. mfERG showed the retina function of macular region. Comparingwith pretreatment, the amplitude density of P1-wave and N1-wave at macular (one, two ring) had no statistically differences (P>0.05), and they(two ring) were significantly increased (P<0.05) after three monthstreatment, the incubation of P1-wave and N1-wave at macular (one, tworing) was shorten, but no statistically differences (P>0.05). After threemonths treatment, the amplitude density and incubation of P1-wave andN1-wave at one ring had no correlation with relative BCVA (r=-0.043,P>0.05; r=0.407, P>0.05; r=0.151, P>0.05; r=-0.100, P>0.05); theamplitude density and incubation of P1-wave and N1-wave at two ringalso had no correlation with relative BCVA (r=0.326, P>0.05; r=0.383,P>0.05; r=0.307, P>0.05; r=0.424, P>0.05).5. The mean sensitivity, mean defect at macular (central10degree)were significantly improved after three months treatment, statisticallysignificant differences were existed (P<0.01). After treatment, the meansensitivity and mean defect had a positive correlation with relative BCVA(P<0.01).No visual field defect related with RON was observed.6. After treatment, three eyes has high intraocular pressure (≥21mmHg), but the pressure decreased to normal by applying local drops.One eye had iris neovascularization, and then iris neovascularizationdisappeared after one week by retinal photocoagulation.Conclusions:1. Combined therapy has significantly curative effect to visionimprovement, macular edema alleviation and retinal hemorrhageabsorption for patients of ischemic CRVO.2. There was no statistical difference between RON group andNon-RON group for vision improvement and macular edema; howeverthe clinical curative effect of RON needs sizable sample and long termfollow-up and observation.3. The vision prognosis of ischemic CRVO patients depends on thepretreatment vision.