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Objective To observe the alterations ofmicrovascular structure in patients with macular edema (ME) associated with branch retinal vein occlusion (BRVO) before and after anti-VEGF drug therapy.Methods A retrospective case study.Thirty-two eyes of 32 patients with unilateral BRVO-ME at Department of Ophthalmology in Beijing Hospital during November 2016 to June 2018 were enrolled in this study.There were 14 males (14 eyes) and 18 females (18 eyes),with the mean age of 57.81 ± 10.58 years,and the mean course of the disease of 12.13 ± 7.13 d.The affected eyes was defined as the eyes with BRVO-ME.All the affected eyes received intravitreal anti-VEGF drug injections (3+PRN).BCVA and OCT angiography (OCTA) were performed on the BRVO and fellow eyes before and after intravitreal anti-VEGF drug injections.The scanning region in the macular area was 3 mm × 3 mm.Macular blood flow density in the superficial capillary plexus (SCP) and deep capillary plexus (DCP),macular hemodynamics parameters [foveal avascular area (FAZ) area,perimeter (PERIM),acircularity index (AI) and vessel density within a 300um width ring surrounding the FAZ (FD-300)] and central retinal thickness (CRT) were measured in all eyes.Paired samples t-test and Univariate Linear Regression were used in this study.Results Comparing with fellow eyes,the mean macular blood flow density measured in the entire scan was lower in BRVO-ME eyes in the SCP (t=6.589,P=0.000) and DCP (~9.753,P=0.000),PERIM (t=4.054,P=0.000)),AI enlarged in BRVO-ME eyes (t=4.988,P=0.000),FD-300 was lower in BRVO-ME eyes (t=2.963,P=0.006),FAZ area enlarged in BRVO-ME eyes (t=0.928,P=-0.361).The blood flow density in the DCP was the parameter most significantly correlated with BCVA and FAZ area (r=0.462,-0.387;P＜.05).After 3 intravitreal injections of anti-VEGF drug,the CRT and FD-300 decreased,BCVA increased (t=9.865,3.256,-10.573;P＜0.05),PERIM and AI was not changed significantly (t=0.520,2.004;P＞0.05).The blood flow density in the SCP decreased (t=2.814,P＜0.05),but the blood flow density in the DCP was not changed significantly (t=0.661,P=-0.514).Contrarily,comparing with after 1 antiVEGF drug injection,the blood flow density in the DCP increased after 2 anti-VEGF drug injections (t=3.132,P＜0.05).FAZ area enlarged in BRVO-ME eyes (t=5.340,P＜0.001).Comparing with last anti-VEGF drug injection,FAZ area enlarged after every anti-VEGF drug injection (t=2.907,3.742,2.203;P＜0.05).Conclusions In BRVO-ME eyes,the blood flow density in the SCP and DCP are decreased.The blood flow density in the DCP is positively correlated with BCVA and negatively correlated with FAZ area.After antiVEGF drug therapy,the blood flow density is decreased in the SCP and increased in the DCP,FAZ area enlarged gradually,PERIM and AI are not changed significantly.
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Macular edema is a common cause of visual loss in patients with retinal vascular diseases represented by diabetic retinopathy and retinal vein occlusion.Laser photocoagulation has been the main treatment for this kind of diseases for decades.With the advent of antagonist of vascular endothelial growth factor and dexamethasone implant,diabetic macular edema and macular edema secondary to retinal vein occlusion have been well controlled;the use of laser therapy is decreasing.However,considering possible risks and complications,lack of extended inspection of efficacy and safety of intravitreal pharmacotherapy,laser therapy cannot be replaced by now.Therefore,the efficacy and safety of laser therapy will improve by sober realization of role of photocoagulation and proper selection of treatment indication.
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Objective To observe the effect of macular retinal thickness (CMT) on the long-term visual prognosis after intravitreal injection of Conbercept combined with retinal laser photocoagulation for macular edema (ME) secondary to branch retinal vein occlusion (BRVO).Methods A retrospective non randomized controlled study.Forty-one patients (41 eyes) of ischemic BRVO secondary ME were included in the study.Among them,there were 23 males (23 eyes) and 18 females (18 eyes).The average age was (56.49±8.94) years.The best corrected visual acuity (BCVA) and optical coherence tomography were performed.The mean logMAR BCVA was 0.82±0.41,and the mean CMT was (512.61 ± 185.32) μrn.According to the CMT reduction value at 1 month after treatment,the eyes were divided into no response group and response group,each has 15 patients of 15 eyes and 26 patients of 26 eyes respectively.The age and sex composition of the two groups were not statistically significant (t=-0.298,-1.708;P=0.767,0.096),and the difference of frequency of injection was statistically significant (t=3.589,P=0.010),and there was no statistical difference between the patients with logMAR BCVA and CMT (t=2.056,-1.876;P=0.460,0.070).The average follow-up was 8 months.The logMAR BCVA on 6 months after treatment was defined as long term vision.The changes of long term vision and CMT on 1 and 6 months of two groups after treatment were observed.Pearson correlation analysis showed that the correlation between long-term vision and age,logMAR BCVA before treatment,CMT before treatment,frequency of injection,and CMT value decreased 1 month after treatment.The correlation of long-term visual acuity with age,sex,logMAR BCVA before treatment,CMT before treatment,number of drugs before treatment,CMT reduction at 1 month after treatment,integrity of ellipsoid band and integrity of external membrane (ELM) were analyzed by multiple regression analysis.Results On 1 month after treatment,the CMT of the eyes was lower than that before treatment (231.48± 177.99) μm,and the average integrity of ELM and ellipsoid were 0.56±0.50 and 0.41 ±0.50 respectively.On 6 months after treatment,the average logMAR BVCA of the eyes was 0.48 ± 0.34.The results of Pearson correlation analysis showed that the long-term vision was positively correlated with the logMAR BCVA before treatment and the number of CMT reduction and the number of drug injection at 1 month after treatment (P＜0.05);there was no correlation with age and CMT before treatment (P＞0.05).The results of multiple regression analysis showed that the long-term vision was associated with logMAR BVCA before treatment,CMT reduction,ELM integrity,and the number of times of injection (P＜0.05),and no correlation with age,sex,CMT before treatment and the integrity of the ellipsoid (P＞0.05).On the 6 months after treatment,the logMAR BCVA in the non-response group and the response group were 0.86±0.23 and 0.26±0.14,and the average CMT was respectively (398.93±104.87) and (255.15 ± 55.18) μrn,and the average injection times were respectively (2.53 ± 1.46) and (1.31 ± 0.74) times.The average logMAR BCVA,CMT and injection times of the two groups were statistically significant (t=10.293,5.773,3.589;P=0.000,0.000,0.001).No complications related to drug or intravitreal injection occurred in all patients.Conclusion The long-term vision of ME secondary to BRVO after intravitreal injection of Conbercept combined with retinal laser photocoagulation was associated with the decrease of CMT and the integrity of the ELM after 1 month of treatment,no correlation was found between CMT and ellipsoid integrity before treatment.
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Retinal vein occlusion (RVO) is the second visual threatening retinal disorders followed by diabetic retinopathy in the elderly.In the past decades,increasing knowledge of the natural history,aetiology and risk factors,medical management investigation,together with the support of high level evidence-based medical evidence and the results of real-world clinical trials play key roles in guiding the clinical practice.However,without understanding the pathogenesis and pathogeny of the disease,it is difficult to implement a comprehensive,precise and personalized treatment strategy for the RVO patients.It is of significance in the clinic to discuss the pathological process of RVO,analyze the etiological characteristics of the disease,reveal the clinical outcomes,which aim to facility the optimal treatment and follow-up procedure for the patients.
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Pharmaceutical therapy,including anti-vascular endothelial growth factor treatment and intravitreal corticosteroids,is the most common treatment for branch retinal vein occlusion (BRVO) and its complications,however there are confusing ideas about the protocol,patient selection,timing and endpoint of this treatment.The disease is easy to relapse with these drugs therapy.Collateral vessel formation was found in patients receiving intravitreal injection of ranibizumab or triamcinolone for BRVO and secondary macular edema.The mechanism of collateral vessel formation has not been carefully investigated.In the past thrombolysis,arteriovenous fasciostomy and laser choroidal retinal vascular anastomosis were used to reconstruct the retinal circulation,but their rationality,effectiveness and safety need to be further were studied.In recent years,because of the key technology is still immature,the artificial vascular bypass surgery experiment is not yet practical,but provides us a new idea worth looking forward to for the treatment of BRVO.
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Objective To study and compare the clinical efficacy between intravitreal conbercept injection and (or) macular grid pattern photocoagulation in treating macular edema secondary to non-ischemic branch retinal vein occlusion (BRVO).Methods Ninety eyes of 90 patients diagnosed as macular edema secondary to non-ischemic BRVO were enrolled in this study.Forty-eight patients (48 eyes) were male and 42 patients (42 eyes) were female.The average age was (51.25 ± 12.24) years and the course was 5-17 days.All patients were given best corrected visual acuity (BCVA),intraocular pressure,slit lamp with preset lens,fluorescence fundus angiography (FFA) and optic coherent tomography (OCT) examination.The patients were divided into conbercept and laser group (group Ⅰ),laser group (group Ⅱ) and conbercept group (group Ⅲ),with 30 eyes in each group.The BCVA and central macular thickness (CMT) in the three groups at baseline were statistically no difference (F=0.072,0.286;P=0.930,0.752).Patients in group Ⅰ received intravitreal injection of 0.05 ml of 10.00 mg/ml conbercept solution (conbercept 0.5 mg),and macular grid pattern photocoagulation 3 days later.Group Ⅱ patients were given macular grid pattern photocoagulation.Times of injection between group Ⅰ and Ⅲ,laser energy between group Ⅰ and Ⅱ,changes of BCVA and CMT among 3 groups at 1 week,1 month,3 months and 6 months after treatment were compared.Results Patients in group Ⅰ and Ⅲ had received conbercept injections (1.20 ± 0.41) and (2.23 ± 1.04) times respectively,and 6 eyes (group Ⅰ) and 22 eyes (group Ⅲ) received 2-4 times re-injections.The difference of injection times between two groups was significant (P＜0.001).Patients in group Ⅱ had received photocoagulation (1.43 ±0.63) times,9 eyes had received twice photocoagulation and 2 eyes had received 3 times of photocoagulation.The average laser energy was (96.05 ±2.34) μV in group Ⅰ and (117.41 ±6.85) μV in group Ⅱ,the difference was statistical significant (P=0.003).BCVA improved in all three groups at last follow-up.However,the final visual acuity in group Ⅰ and group Ⅲ were better than in group Ⅱ (t=4.607,-4.603;P＜0.001) and there is no statistical significant difference between group Ⅲ and group Ⅰ (t=-0.802,P=0.429).The mean CMT reduced in all three groups after treating for 1 week and 1 month,comparing that before treatment (t=-11.855,-10.620,-10.254;P＜0.001).There was no statistical difference of CMT between group Ⅰ and Ⅲ at each follow up (t=0.404,1.723,-1.819,-1.755;P=0.689,0.096,0.079,0.900).CMT reduction in group Ⅰ was more than that in group Ⅱ at 1 week and 1 month after treatments (t=-4.621,-3.230;P＜0.001,0.003).The CMT in group Ⅲ at 3 month after treatment had increased slightly comparing that at 1 month,but the difference was not statistically significant (t=1.995,P=0.056).All patients had no treatment-related complications,such as endophthalmitis,rubeosis iridis and retinal detachment.Conclusions Intravitreal conbercept injection combined with macular grid pattern photocoagulation is better than macular grid pattern photocoagulation alone in treating macular edema secondary to non-ischemic BRVO.Combined therapy also reduced injection times comparing to treatment using conbercept injection without laser photocoagulation.
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Objective To evaluate the effectiveness of repeated intravitreal conbercept injection in patients with macular edema (ME) of retinal vein occlusion (RVO),guided by optic coherence tomography (OCT).Methods It is a retrospective case study.Forty patients (40 eyes) diagnosed as ME secondary to RVO were enrolled in this study.There were 19 males (19 eyes) and 21 females (21 eyes),with the mean age of (53.58 ± 13.19) years and the mean course of 1.5 months.The best corrected visual acuity (BCVA),indirect ophthalmoscopy,fundus fluorescein angiography (FFA) and OCT were performed.The mean baseline of BCVA,central macular thickness (CMT) were 0.25 ± 0.18 and (509.48 ± 170.13) μm respectively.All the patients were treated with 10.00 mg/ml conbercept 0.05 ml (including conbercept 0.5 mg).Follow-up of these patients was 1 to 6 months after treatments,the BCVA,fundus manifestations,OCT were retrospectively observed by every month,the FFA was retrospectively observed by every 3 months.When there was retinal edema or CMT ≥ 50 μm by OCT during follow-up,those patients were retreated with intravitreal conbercept injection.The changes of the BCVA,CMT were evaluated before and after treatment.Meanwhile,complications in eyes related to medicine and treatment methods were evaluated too.Results At the 6 months,the BCVA was improved (increase≥2 lines) in 25 eyes (62.50％),stabilized (± 1 line) in 13 eyes (32.50％) and decreased 2 lines in 2 eyes (5.00％).Retinal hemorrhage and exudates were absorbed in most patients.FFA showed no fluorescein leakage in 1 1 eyes (27.50％),minor fluorescein leakage in 26 eyes (65.00％),and retinal capillary non-perfusion in 3 eyes (7.50％).OCT showed absorption of the subretinal fluid.The mean CMT were (235.20± 100.44) μm at 6 months.Intravitreal injection of conbercept was applied for 4 times in 8 eyes (20.00％),3 times for 18 eyes (45.00％),and 2 times for 14 eyes (35.00％).The mean number of intravitreal injection was 2.85 times.There were no ocular or systemic adverse events observed in all patients.Conclusion Intravitreal conbercept injection is an efficacy and safe treatment for the patients with ME of RVO guided by OCT.It can stabilize and improve the visual acuity.
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Background Central retinal vein occlusion (CRVO) is a common retinal vascular disease.Intravitreal injection of ranibizumab, a vascular endothelial growth factor (VEGF) antibody, is being a useful approach to the treatment of macular edema secondary to CRVO.However,little literature about choroidal thickness variations following intravitreal injection of ranibizumab for CRVO is published up to now.Objective This study was to observe the dynamic changes of macular choroidal thickness after intravitreal injection of ranibizumab in CRVO eyes.Methods A self-controlled series cases study was designed.Thirty-one eyes of 31 CRVO patients were included in Tianjin Eye Hospital from June 2013 to November 2014,with the males 19 and females 12 and mean age of (51.13±16.65) years.Ranibizumab (5 mg,5 ml) was intravitreally injected in the CRVO eyes once per month for 3 times by the same operator.A enhanced depth image (EDI) mode of spectral-domain OCT system was employed to measure the choroidal thickness at subfoveal, 1 mm from fovea nasal and 1 mm from fovea temporal before and 1 month,2,3 months after first injection in both CRVO eyes and contralateral healthy eyes, respectively.The best LogMAR vision was recored.This research protocol was approved by the Ethic Committee of this hospital, and written informed consent was obtained from each individual prior to any medical examination.Results Retinal bleeding was exhibited in the CRVO eyes in color photography,and fundus fluorescein angiography showed the fluorescine leakege in the early phase and fluorescine accummulation in the late phase.The mean choroidal theckness value was (325.32±83.04) , (294.83±80.61), (315.95±90.77) and (314.81±84.98) μm before injection and 1,2,3 months after injection,respectively,showing a significantly difference among various time points (F =7.96,P =0.00) , and the choroidal theckness values were evidently reduced in various time points after injection in comparison with before injection (P =0.01,0.01,0.00).The choroidal thickness value at foveal was (314.81±84.98) μm in the CRVO eyes 3 months after injection,and that in the fellow eyes was (260.47±55.90) ,with significant difference between them (t =2.95, P =0.01).The LogMAR vision was 0.17±0.09,0.37±0.23,0.42±0.26 and 0.49±0.21 before and 1,2,3 months after injection,with the significant difference among various time points (F =21.50, P =0.00) and showed considerable improvement after intravitreal injection of ranibizumab(all at P＜0.01).The mean retinal thickness value was (244.14-±23.28) μm in the fellow eyes, and those in 1 month, 2,3 months after injection were (523.81 ± 147.61), (352.13 ± 166.71),(376.39±209.46) and (369.00±225.61) μm in the CRVO eyes, showing obvious reduce after intravitreal injection, with significant difference among different time points (F =7.09, P＜0.01).Conclusions Choroidal thickness at macular fovea is obviously increased in CRVO eyes compared with the contralateral healthy eyes.Intravitreal injection of ranibizumab can reduce choroidal thickness and therefore improve vision.EDI OCT is available in the evaluation of dynamic change of choroidal thickness.Macular choroidal thickness could be used as a predictor of CRVO prognosis following intravitreal ranibizumab.
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Background Retinal vein occlusion is a common retinal vascular diseases.Thromblysis and anticoagulation therapies are main approaches.However,systemic thrombolysis is relatively inefficient,and it often enhances the risk of hemorrhage.Objective This study was to investigate the therapeutic effects of PLM-ΔK,a kringle deficiency mutant of plasmin,on photochemically induced branch retinal vein occlusion (BRVO) after intravitreal injection.Methods BRVO models were established by the combination of caudal vein injection of Rose Bengal with argon laser radiation of periphery area of retinal veins in SD rats.Forty model rats were randomized into balance salt solution (BSS) group and 0.01 U,0.02 U,0.03 U PLM-ΔK group,and 10 μl corresponding drug was intravtreally injected 12 hours after modeling.Ophthalmoscopy and fundus fluorescein angiography (FFA) were performed to observe the change of retinal veins.The animals were sacrificed 3 days after intravitreal injection,and hematoxylin and eosin staining was used for the histopathological and ultrastructural examination of retinas.The retina of the rats was isolated for the stretched preparation of retina.The expressions of fibronectin (FN) and laminin (LN) in eyeball wall were assayed by immunofluorescence technology.The use and care of the animals complied with Statement of the Association for Research in Vision and Ophthalmology.Results The revascularization of over 2 retinal veins was found in 0,3,6 and 8 rats in the BBS group and 0.01 U,0.02 U,0.03 U PLM-ΔK group 3 days after intravitreal injection,respectively,showing a significant difference among the groups (x2=9.635,P =0.022),and the rat number with revascularization in 0.01 U PLM-ΔK group was not significantly different from that in BSS group (Z=-1.558,P =0.119),but the difference between 0.03 U PLM-ΔK group and 0.01 U PLM-ΔK group was significant (Z=-2.762,P=0.006).In the third day after intravitreal injection,retinal vein thrombus were found in the BSS group under the light microscope,and angiogenesis was seen on the retinal flatmount nuclear.In the 0.03 U PLM-ΔK group,posterior vitreal detachment was exhibited under the light microcope,and no retinal new vessel and cell damage were seen.FN was strongly expressed in the inner limiting membrane (ILM) layer,photocyte layer,outer limiting membrane (OLM) layer,choroid and scleral layer,and LN was expressed mainly in the ILM,OLM and scleral layer in the BSS group.However,the expression intensities of FN and LN were obviously weakened in the 0.03 U PLM-ΔK group.Conclusions Intravitreal injection of PLM-ΔK can enhance the reperfusion of occluded branch retinal vein and serve as a potential therapeutic drug for BRVO.Also it can permeate into choroid after intravitreal injection to degradate FN and LN.
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Objective To investigate the efficacy and safety of intravitreal ranibizumab and (or) triamcinolone combined with laser photocoagulation for macular edema secondary to branch retinal vein occlusion (BRVO) during one year period.Methods The data of 31 eyes from 31 consecutive patients with macular edema secondary to BRVO during one year follow-up visit were retrospectively analyzed.Mean best corrected visual acuity (BCVA) logMAR was (0.74±0.36) and mean central retinal thickness (CRT) was (484.48± 164.81) μm at baseline.All patients received standardized clinical comprehensive examinations including vision,intraocular pressure and optical coherence tomography for diagnosis before treatment.All patients received intravitreal injections of 0.5 mg ranibizumab (0.05 ml) at first visit.The continue PRN treatment were based on the visual acuity changes and the optical coherence tomography findings.Eyes received combined triamcinolone acetonide 0.05 ml (40 mg/ml) and ranibizumab for macular edema recurrence after two injections of ranibizumab and received laser photocoagulation during 10-14 days after third injections of ranibizumab.Mean injection of ranibizumab was 3.52± 2.01,15 eyes with triamcinolone acetonide (0.84 ± 1.21),21 eyes with laser photocoagulation (0.97± 0.95) and 12 eyes with three treatment.Compared the visual acuities and CRTs of the first and the last visits by statistical analysis.Results Mean visual acuity improved significantly to 0.42±0.33 logMAR (t=6.611,P=0.000).Mean improvement of visual acuity was 2.90± 3.07 lines.A gain of three or more logarithmic lines was evaluated in 20/31 eyes (64.52％) at the last visit.Mean CRT was (326.19± 117.80) μm (t=4.514,P=0.000).Mean reduction of CRT was (333.58±134.17) μm.A decrease of 100 μm of CRT was evaluated in 17/31 eyes (54.84％).No severe ocular and systematic side effect was found.Conclusion The efficacy and safety of intravitreal ranibizumab and (or) triamcinolone combined with laser photocoagulation for macular edema secondary to BRVO were assured.
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Objective To observe the clinical features and outcomes of vitrectomy for diabetic retinopathy (DR) with central retinal vein occlusion (CRVO) in type 2 diabetes mellitus (T2DM).Methods A total of 192 patients (241 eyes) with proliferative DR (PDR) who underwent vitrectomy were enrolled in this study.All the patients were diagnosed as vitreous hemorrhage (VH) because of suddenly decreased vision.There were 93 eyes with tractional retinal detachment (TRD) and six eyes with neovascularization of iris (NVI).The patients were divided into PDR with CRVO group (group A,41 eyes) and PDR group (group B,200 eyes) according to the results of fundus examination.All patients received vitrectomy with silicone oil and C3F8 gas tamponade.There were 138 eyes with silicone oil tamponade which including 30 eyes in group A and 108 eyes in group B.The difference of number in silicone oil-filled eyes in two groups was statistically significant (x2=5.110,P＜0.05).There were 38 eyes with C3F8 gas tamponade which including six eyes in group A and 32 eyes in group B.There was no difference in C3F8 gas-filled eyes numbers in two groups (x2 =0.048,P＞0.05).The follow-up ranged from one to 60 months,with the mean of (28.69± 17.28) months.The corrected vision,retinal reattachment,persisting macular edema (ME),neovascular glaucoma (NVG) and repeated VH after surgery were comparatively analyzed.Results Of 241 eyes,there were 41 eyes (17.0％) with CRVO.Before surgery,the differences of corrected vision (Z=-0.138),intraocular pressure (t=0.966),whether there was TRDor not (x2=0.412),whether underwent panretinal photocoagulation or not (x2 =1.416) were not statistically significant (P＞0.05),but the difference of whether NVI were present or not was statistically significant (x2=31.724,P＜0.05)between two groups.After surgery,the corrected vision improved in both two groups (Z=2.319,4.589;P＜0.05).There was no difference of corrected vision after surgery between two groups (Z=0.782,P＞0.05).Postoperative complications occurred in 94 eyes,including 26 eyes in group A and 68 eyes in group B.The differences of incidence of reoperation (x2 =0.498),retinal reattachment (x2 =0.818),persisting ME (x2 =2.722) between two groups after surgery were not statistically significant (P ＞ 0.05).The incidence of repeated VH (x2 =5.737) and NVG (x2 =6.604) in group A were higher than those in group B (P＜ 0.05).Conclusions CRVO is commonly found to coexist with DR in T2DM patients with VH.Combined with CRVO patients are more likely to suffer NVI.Vitrectomy can improve the visual function in PDR with CRVO patients.
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Objectives To evaluate the therapeutic effect of argon laser photocoagulation combined with intravitreous injection of triamcinolone acetonide (TA) on ischemic central retinal vein occlusion (CRVO). Methods Argon laser photocoagulation combined with intravitreous injection of TA was performed on 17 patients (17 eyes) with CRVO between December 2003 and July 2004. Results During the follow-up of 4-10 months, the visual acuity improved in 16 patients, including alleviated or even disappeared cystoid macular edema (CME) in 5, and recurred macular edema in 5 with decreased visual acuity after 3 months. Six patients had increased ocular pressure after intra-ocular injection which alleviated after treated suitably. No neovascularization in angle or secondary neovascular glaucoma was found. Conclusion [WTBZ]Argon laser photocoagulation combined with intravitreous injection of TA may improve the visual acuity and reduce complications in ischemic CRVO, though macular edema may recur in some cases.
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0.05). But the mean light sensitivity at central 10? eccentricity were significantly decreased 3 months after photocoagulation (P
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Objective To evaluate the therapeutic effect of laser induced chorioretinal venous anastomosis on macular edema of non ischemic retinal vein occlusion. Methods Thirty seven eyes of 37 cases of non ischemic retinal vein occlusion received the treatment of laser induced chorioretinal venous anastomosis and were followed up for 6～12 months. All affected eyes underwent the clinical examinations of visual acuity, ocular fundus photography, fundus fluoreceine angoigraphy (FFA) and light sensitivity of central 5 degree of the retina, and the pre and post operative clinical materials were analyzed. Results Successful chorioretinal venous anastomosis was formed in 18 eyes (48.6%) within 2 months after laser photocoaglation, with the mean best improved corrected visual acuity of (4 25?0 46) lines, while the mean best corrected visual acuity of the other 19 eyes with unsuccessful anastomosis decreased (0 20?0 54) lines ( P
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Objective To inspect the rate of success of anastomosis and tissue damage with different power levels of photocoagulation in the treatment of experimental branch retinal vein occlusion (BRVO) by laser induced chorioretinal venous anastomosis. Methods Forty pigmented rabbits (80 eyes) were divided into four groups in random, and 10 (20 eyes) in each. Chroioretinal venous anastomosis was attempted to create using the krypton red laser with 4 different power levels (group A: 400 mW,group B: 600 mW,group C: 800 mW,group D: 1000 mW) in these animals in which BRVO had previously been created photodynamically. Fundus photography and fundus fluorescein angiography were performed at various times after the treatment and histological examination was taken at the end of the study. Results The model of BRVO was successfully set up. At the lowest power of 400 mW there was an absence of anastomosis formation and the damage to the retina and choroid was mild, Bruch′s membrane showed no evidence of rupture. At the power levels of 600 mW and 800 mW an anastomosis formed in 15% and 55% respectively and the damage was medium in degree. At the highest power level of 1 000 mW a 80% rate of success was obtained, however, the damage to the retina and choroid tended to be severe. The difference of the rate of success of anastomosis between different groups was highly significant ( P =0 001), the difference between group B and group C was also highly significant ( P BC =0.008), and the difference between group A and group B, group C and group D was not significant ( P AB =0 072、 P CD =0 091). Conclusion The optimal power level of krypton red laser induced chorioretinal venous anastomosis is 800 mW, 0.1 s, 50 ?m in our study.