Effect Of Selective Retinal Photocoagulation During Vitretomy For Proliferative Diabetic Retinopathy

Background and ObjectiveDiabetic retinopathy?DR?is one of the common capillaryvascular complications of diabetes mellitus,which is one of the main causes of blindness in adults.Retinal photocoagulation can treat retinal and choroidal diseases by producing thermal effects on them.There are many kinds of photocoagulation.Panretinal photocoagulation?PRP?can effectively alleviate the retinopathy and protect eyesight,which is the routine treatment for proliferative diabetic retinopathy?PDR?at present.PRP can be done several times or steps in clinical for people whose retinopathy is not at high risk.But for people who has PDR and vitreous hemorrhage,PRP is still advocated finished one time in vitrectomydue to the retinopathy has been advanced and complexible.However,photocoagulation is a invasive treatment.A number of photocoagulation points will produce inflammation of the retina,macular edema,retinal edema and so on.Selective retinal photocoagulation?SRP?to block lesions on retinal can reduce the pointsin vitrectomy.Photocoagulation can be added on the rest parts of retinal after the operation.At present,there is no exact evidence of whether this method is safe and effective in clinical.With anti-vacular Endothelial growth factor?anti-VEGF?drugs and glucocorticoid is widely used in clinical,the effect of them for vitrectomy and retinal photocoagulation to treat DR has cause more and more attentions.Intravitreal injection of anti-VEGF and glucocorticoid can not only remove neovascularization on the retina and make operation easily.These drugs can also prevent the reformation of neovascularization and reduce the incidence of complications.They can provide a safe period after vitrectomy for supplementary photocoagulation.23-Gauge microincision vitrectomy has the advantages of little trauma and rapid healing of the wound.For people who need for retinal photocoagulation after surgery,microincision vitrectomy can reduce discomfort and infection of eyes.The purpose of this study is to observe the clinical efficacy and safety of SRP in the treatment of PDR with the assistance of anti-VEGF drugs,corticosteroids and microincision vitrectomy.The results compared to the efficacy of PRP during operation.MethodsCollected patients suffering from vitreous hemorrhage caused by proliferative diabetic retinopathywho diagnosed in the First Affiliated Hospital of Zhengzhou University from January 2015 to December 2015.There are 190 patients?200 eyes?in in this retrospective study.All of them were injected anti-VEGF before vitrectomy.During the vitrectomy,all of them accepted retinal photocoagulation.At the end of the surgery,they also acceped intravitreal injection of glucocorticoid.These patients are divided to two groups:One is contral group?102 cases,108 eyes?who received PRP during the vitrectomy,the other one is observation group?88 cases,92 eyes?who received SRP during the vitrectomy.Retinal photocoagulation in control group according to standard-PRP during surgety,The laser points was?1646.96±241.61?.Patients in contral group receive retinal photocoagulation after surgery when the retinal has hypoxia signs.Retinal photocoagulation inobservation group spread onthe ischemia and hypoxia region The method of photocoagulation was same with the control group.The laser points was?799.67±117.53?.Patients in observation group receive photocoagulationgradually2 weeks after the operation.The points was 300 to 500 once a week.The patients of the two group were followed up for 6 months or more.Best corrected visual acuity,central macular thickness,the rate of recurrent vitreous hemorrhage,the number of retinal photocoagulation after vitrectomy and the rate of neovacular glaucoma were comparatively analyzed between the two groups.ResultsThe mean of BCVA at 1 weeks,1 month and 3 months after operation in observation group were all higher than in contral group.The differences was statistically significant(Z_{1 WK}=-6.290,P=0.000;Z_{1 mo}=-7.398,P=0.000;Z_{3 mo}=-7.955,P=0.000).But the difference was not statistically significant between the two groups at 6 months(Z_{6 mo}=-1.676,P=0.094).The mean of central macular thickness after vitrectomy in observation group at 1 week,1 month after vitrectomy were all lower than that in contral group.The differences have statistically significant between the two groups(Z1WK=-8.822,P=0.000;Z_{1 mo}=-6.569,P=0.000).But the difference was not statistically significance between the two groups at 3 months?Z=-0.934,P=0.349?.The frequencies of retinal photocoagulation after vitrectomy in observation group was 2.99±1.77 and 0.17±0.66 in contral group.The number in observation group was higher than that in contral group?Z=-12.360,P=0.000?.The number of recurrent vitreous hemorrhage was 1.852%?2/108?in contral group and 3.261%?3/92?in observation group.The rate of neovacular glaucoma appearence was 0.926%?1/108?in contral group and 2.174%?2/92?in observation group.The differences of these numbers between the two groups were not statistically significant?P>0.05?.ConclusionUnder the application of anti-VEGF drugs,glucocorticoid drugs and micro-invsive vitrectomy,we can use selective retinal photocoagulation during vitrectomy which the photocoagulation points are low to treat people who has proliferative diabetic retinopathy and vitreous hemorrhage.This technology can avoid the side-effects of PRPwhich has a lot of points during vitrectomy and reduce the macular edema,improve visual acuity.Patients' satisfaction of the surgery can also improved.