Radiation Retinopathy Associated with Central Retinal Vein Occlusion

Purpose: To report a case of radiation retinopathy associated with central retinal vein occlusion. Methods: The clinical features and fundus fluorescein angiography of this case were analyzed. Results: The patient had been treated with radiotherapy for her nasopharyngeal carcinoma, and presented with sudden visual loss in the left eye. The funduscopic examination and fluorescein angiography showed the features of radiation retinopathy in both eyes, and central retinal vein occlusion in the left eye. Conclusions: Radiation retinopathy can be associated with central retinal vein occlusion in the same eye, and it seems that the endothelial cell loss caused by radiation retinopathy may lead to retinal vein occlusion.     

Classification of Central Retinal Vein Occlusion

Our prospective clinical study of 360 eyes with central retinal vein occlusion (CRVO) and our experimental studies on CRVO in 54 eyes of rhesus monkeys have shown that CRVO consists of the following two distinct entities: (1) Nonischemic CRVO in which there is essentially a stasis of retinal venous circulation; we call it venous stasis retinopathy (VSR). (2) Ischemic CRVO: We call this hemorrhagic retinopathy (HR). Our prospective clinical studies have revealed that it is absolutely essential to differentiate CRVO into VSR and HR because of their very different prognoses and management. VSR is a benign and self-limited condition, while HR is a severe, potentially blinding disorder. Lumping the two types of CRVO together as one disease has caused much confusion concerning the prognosis and management of CRVO. The basis of such a classification and differential diagnosis of VSR and HR is discussed at length.     

Retinal Vein Occlusion in a Multi-Ethnic Asian Population: The Singapore Epidemiology of Eye Disease Study

Purpose: To describe the prevalence of retinal vein occlusion (RVO) and its risk factors in a multi-ethnic Asian population.

Methods: This population-based study of 10,033 participants (75.7% response rate) included Chinese, Indian and Malay persons aged 40 years and older. A comprehensive ophthalmic examination, standardized interviews and laboratory blood tests were performed. Digital fundus photographs were assessed for presence of RVO following the definitions used in the Blue Mountains Eye Study. Regression analysis models were constructed to study the relationship between ocular and systemic factors and RVO. Age-specific prevalence rates of RVO were applied to project the number of people affected in Asia from 2013 to 2040.

Results: The overall crude prevalence of RVO was 0.72% (n = 71; 95% confidence interval, CI, 0.54–0.87%). The crude prevalence of RVO was similar in Chinese, Indian and Malay participants (p = 0.865). In multivariable regression models, significant risk factors of RVO included increased age (odds ratio, OR, 1.03, 95% CI 1.01–1.06), hypertension (OR 3.65, 95% CI 1.61–8.31), increased serum creatinine (OR 1.04, 95% CI 1.01–1.06, per 10 mmol/L increase), history of heart attack (OR 2.25, 95% CI 1.11–4.54) and increased total cholesterol (OR 1.31, 95% CI 1.07–1.59, per 1 mmol/L increase). None of the ocular parameters were associated with RVO. RVO is estimated to affect up to 16 and 21 million people in Asia by 2020 and 2040, respectively.

Conclusion: RVO was detected in 0.72% of a multi-ethnic Asian population aged 40–80 years in Singapore. The significant systemic risk factors of RVO are consistent with studies in white populations.     

Characteristics of the Hemispheric Retinal Vein Occlusion

Hemispheric retinal vein occlusions involve the venous return from approximately one-half of the retina and have characteristics of both central retinal vein occlusions and branch retinal vein occlusions. One hundred six such occlusions were studied in 104 patients whose average age was 66 years. The site of the hemispheric vein occlusion was located in a branch retinal vein in 90% of the eyes, and in 10% of the eyes it was located in one of the dual intraneural trunks of the central retinal vein. Of these eyes, 11 developed neovascularization of the disc, 9% developed neovascularization of the retina elsewhere, 9% developed neovascularization of the iris, and 3% developed neovascular glaucoma. Neovascularization was positively correlated with an increasing percentage of capillary nonperfusion (ischemic index) within the area of occlusion. Prophylactic argon laser treatment was effective in reducing the incidence of neovascularization in eyes with significant capillary nonperfusion.     

玻璃体切除术治疗视网膜静脉阻塞所致的玻璃体出血

报告应闭合式玻璃体切除术治疗７例（７眼）因视网膜静脉阻塞所致的玻璃体出血。所有病人术后眼底清晰可见，视力明显提高。术后４例出现再出血，经药物治疗后出血吸收，加用氩离子激光视网膜光凝，无再出血。随访３至１８个月所有病人无新生血管性青光眼及牵引性视网膜脱离出现。认为玻璃体切除术不但能使屈光间质恢复透明，视力提高，预防牵引性视网膜脱离，而且为明确诊断和进一步激光治疗提供条件。     

The Management of Central Retinal Vein Occlusion

Central retinal vein occlusion is the result of outflow obstruction and is associated with a variety of medical conditions, mainly affecting the vascular system. Treatment of the coexistent medical conditions has no beneficial effect on visual outcome. Outflow obstruction has been treated by fibrinolytic agents and anticoagulants, hemodilution, and photocoagulation. None of these treatments were of value in improving or maintaining vision. Photocoagulation prevents neovascular complications in ischemic central retinal vein occlusion.     

Evaluation of a Patient with Central Retinal Vein Occlusion

Patients suffering a central retinal vein occlusion should be evaluated for conditions that promote and/or contribute to the formation of a thombosis in the central retinal vein. These conditions include alterations of blood flow, altered viscosity of the blood, abnormalities of coagulation, and abnormalities of vessel walls. Patients with either a partial or complete central retinal vein occlusion have similarities in the age of onset, associated systemic findings, and laboratory data. At the time of onset, 90% of patients are older than 50 years. Seventy-four percent of patients will have symptoms or signs of associated systemic vascular disease (ie, hypertension, arteriosclerotic heart disease, and diabetes mellitus.) The most common laboratory findings include elevated blood lipids, abnormalities of glucose tolerance testing, and abnormalities of protein chemistries. Evaluation should include both a complete ocular and medical examination with appropriate laboratory tests and special studies. Assessment of central retinal venous pressure may be helpful in identifying those patients who have a severe, complete thrombosis and are at significant risk to develop anterior segment neovascularization.     

Radial Optic Neurotomy in Central Retinal Vein Occlusion: Preliminary Results

Background: To investigate the efficacy of radial optic neurotomy (RON) on visual prognosis and clinical findings in central retinal vein occlusion (CRVO). Methods: Prospective, non-randomised, self-controlled comparative trial. Six patients with ischemic CRVO who had visual acuity (VA) less than or equal to 0.1 and duration of CRVO at least 1 month, and 6 patients with non-ischemic CRVO who maintained their VA less than or equal to 0.1 during the minimal follow-up of 3 months underwent pars plana vitrectomy and RON. LogMAR VA measurement and fluorescein angiography were performed before and after surgery. Automated perimetry was obtained from 4 patients at the last visit. Main outcome measures were VA and clinical changes in fundus appearance of CRVO evaluated with fundus photography and fluorescein angiography. Results: Radial optic neurotomy was successfully performed in all 12 patients without serious complications. All patients were of clinical improvement of fundus findings. In 11 (92%) patients, a visual improvement of at least 2 lines was observed. After mean follow-up of 9.3 months, mean improvement in VA was 5.1 ± 3.1 lines (range, 2–14 lines). Cystoid macular oedema and degeneration were observed in 8 (67) patients. Four patients, two of whom had preoperative ocular hypertension had raised intraocular pressure controlled with topical antiglaucoma medication. In late postoperative period, one ischemic eye developed vitreous haemorrhage necessitating vitrectomy and endolaser photocoagulation. Automated perimetry revealed segmental visual field defects in all the examined eyes. Conclusions: Radial optic neurotomy in CRVO yields clinical and visual improvement in majority of the patients. Cystoid macular oedema and degeneration are the major factors responsible for restriction of VA improvement. Further randomised and controlled studies with longer follow-up are essential to establish the appropriate timing and indications of RON in CRVO. This study was presented in part at The 3rd Euretina Congress, Hamburg, Germany, 15–17 May 2003     

Progression of Impending Central Retinal Vein Occlusion to the Ischemic Variant Following Intravitreal Bevacizumab

A 60-year-old woman who had experienced two episodes of amaurosis fugax in her right eye presented with vision loss. Two weeks earlier, at a private clinic, she was diagnosed with impending central retinal vein occlusion (CRVO) of the right eye and received an intravitreal injection of bevacizumab. Two weeks after this injection she was diagnosed with ischemic CRVO. At 11-weeks post-presentation, extremely ischemic features were observed with fluorescein angiographic findings of severe vascular attenuation and extensive retinal capillary obliteration. At 22-weeks post-presentation she was diagnosed with neovascular glaucoma; she experienced no visual improvement over the following several months.     

Branch Retinal Vein Occlusion and Its Management

The natural course of Branch Retinal Vein Occlusion is determined by the site and completeness of the occlusion, the integrity of arterial perfusion to the affected sector and the efficiency of the developing collateral circulation. Most patients with tributary vein occlusion have some capillary fall out and microvascular incompetence in the distribution of the affected retina and vision is significantly compromised in over 50% of patients who have either chronic macular oedema or ischemia involving the perifoveolar arcades. Retinal and capillary vasoproliferation with or without intraretinal or preretinal membrane formation are common sequelae, where inner retinal ischemia is extensive and vitreous hemorrhage is often a distinct threat to vision. Treatment of the sequelae of vein occlusion are largely centered on laser photocoagulation to diseased retina to limit fluid accumulation and abolish preretinal and papillary neovascularization. Vitrectomy and retinal detachment procedures are occasionally required in patients with uncontrolled vitreous hemorrhage and retinal membrane formation which threatens the integrity of the macula. A small proportion of patients with vein occlusion subsequent to vasculitis require medical therapy.     

视网膜分支静脉阻塞与动—静脉交叉的关系

视网膜分支静脉阻塞（BRVO）的阻塞部位多位于动—静脉交叉处。但迄今有关交叉处的动、静脉解剖位置与BRVO的关系仍不十分明了．为了探讨BRVO与动—静脉交叉的关系，作者研究了82眼（76例）BRVO和82眼（82例）无BRVO者的眼底彩色照片和眼底荧光血管造影片发现：BRVO多发生于颞侧（90．3％），尤其是颞上象限（54．95％），且在阻塞处，静脉后位交叉为100％（82／82）；而在三个不同对照组的动—静脉交叉处，静脉后位交叉分别为：B组67．1％（55／82），C组70．0％（49／70），D组74．4％（61／82）。阻塞组分别与三个不同对照组比较有显著差异（P均＜0．001）。提示：静脉后位交叉可能为BRVO的主要危险因素；动脉对静脉的机械压迫可能是BRVO的主要原因之一。此外，还对动—静脉交叉在各象限的分布和类型进行探讨。     

Hyperhomocysteinemia,a Biochemical Tool for Differentiating Ischemic and Nonischemic Central Retinal Vein Occlusion during the Early Acute Phase

Purpose

The purpose of the study was to differentiate ischemic central retinal vein occlusion (CRVO) from nonischemic CRVO during the early acute phase using plasma homocysteine as a biochemical marker.

Methods

Fasting plasma homocysteine, serum vitamin B12, and folate levels were measured in 108 consecutive unilateral elderly adult (age >50 years) ischemic CRVO patients in the absence of local and systemic disease and compared with a total of 144 age and sex matched nonischemic CRVO patients and 120 age and sex matched healthy control subjects.

Results

Homocysteine level was significantly increased in the patients with ischemic CRVO in comparison with nonischemic CRVO patients (p = 0.009) and also in comparison with control subjects (p < 0.001). Analysis also showed that hyperhomocysteinemia was associated with increased incidence of ischemic CRVO (odds ratio, 18) than that for nonischemic CRVO (odds ratio, 4.5). Serum vitamin B12 and folate levels were significantly lower (p < 0.001) in CRVO patients compared to the control but were not significantly different between nonischemic and ischemic CRVO patients (p > 0.1).

Conclusions

Hyperhomocysteinemia can be regarded as useful in differentiating nonischemic and ischemic CRVO during the early acute phase in absence of local and systemic disease in the elderly adult (age >50 years) population.     

Parapapillary Choroidal Microvasculature Dropout in Branched Retinal Vein Occlusion and Glaucoma

PurposeTo investigate parapapillary choroidal microvasculature dropout (MvD) in branch retinal vein occlusion (BRVO) patients and compare them with open-angle glaucoma (OAG) patients using optical coherence tomography angiography (OCT-A).MethodsIn total, 85 eyes of BRVO patients and 85 eyes of OAG patients, matched by age, spherical equivalent, and baseline mean deviation (MD) of the visual field (VF), were assessed. MvD was defined as complete loss of microvasculature within the choroidal layer on OCT-A. Linear regression analysis was used to obtain the slope of the MD change of the VF.ResultsThe presence of MvD on OCT-A was significantly more frequent in OAG eyes (63.1%) compared to BRVO eyes (31.8%). BRVO eyes with MvD showed worse baseline MD of the VF than BRVO eyes without MvD (−10.19 ± 8.50 and −7.77 ± 6.46 dB, respectively; P = 0.045). The presence of MvD was the only factor significantly associated with MD change of the VF in OAG eyes. Lower baseline average RNFL thickness, greater MvD angle, and lower macular superficial vessel density were significantly associated with MD change of the VF in BRVO eyes.ConclusionsOCT-A of the parapapillary area showed choroidal microvasculature impairment in both BRVO and OAG patients. However, the frequency was higher in glaucoma patients with similar degrees of VF damage, which suggests that the glaucomatous process contributes to MvD development. The effect of MvD on VF change was different between BRVO and OAG, suggesting that the underlying pathogenesis may also be different.     

Preliminary Clinical Observation of Arteriovenous Sheathotomy for Treatment of Branch Retinal Vein Occlusion

Purpose: To document the anatomic and functional improvement of six patients with branch retinal vein occlusion (BRVO) following successful arteriovenous adventitial sheathotomy (AAS).Methods: Retrospective study of 6 patients (6 eyes) with BRVO treated with AAS. All patients were not eligible for laser photocoagulation and had both macular edema and intraretinal hemorrhage. The visual acuity was in the range of 0. 4 to 0. 02. All patients underwent pars plana vitrectomy and AAS. The clinical improvement was determined by fundus photograph, fluorescein angiography (FAG), optical coherence tomography (OCT) and multifocal electroretinography (ERG) . All patients were followed postoperatively for an average of 20 months ranging from 12 to 24 months. Results: Sheathotomy and decompression of the arteriole/venule (A/V) crossing were achieved in all 6 patients. 5 patients have improved their best-corrected visual acuity 4 lines or more. The best one could reach to 1. 0. One month after the operation, fundus p     

Rod and Cone a-Waves in Central Retinal Vein Occlusion

Purpose

To evaluate rod and cone a-waves in cases with unilateral central retinal vein occlusion (CRVO).

Methods

Scotopic and photopic flash electroretinograms (ERGs) were recorded in seven patients aged 54–84 with unilateral hemorrhagic CRVO. Rod and cone a-waves were analyzed using photoreceptor models, and Rm _p3 (maximum a-wave amplitude) and S (sensitivity) were calculated.

Results

Decreased rod log?S was found in all seven cases, and decreased cone log?S was found in five cases. In only one case, rod log?S in the fellow eye was decreased. The alterations in rod and cone log Rm _p3 were smaller than those in rod and cone log?S. Of three cases in which ERGs could be recorded again after a certain follow-up period, rod log?S and cone logS became larger in two cases and smaller in one case.

Conclusions

The change in the phototransduction cascade was confirmed not only in rods but also in cones in five of our seven cases of CRVO. The ERG findings might reflect the functional change in the photoreceptor layer after the onset of CRVO. Jpn J Ophthalmol 2005;49:402–410 © Japanese Ophthalmological Society 2005     

Central Retinal Vein Occlusion After Uncomplicated Glaucoma Filtering Procedure Combined with Phacoemulsification

We present a case of central retinal vein occlusion after an combined phacotrabeculectomy in a patient with advanced open angle glaucoma. Possible pathogenetic mechanisms for this complication are discussed.     

Non-ischaemic Central Retinal Vein Occlusion after Dengue Viral Infection

Although uncommon, dengue fever is known to be associated with a variety of ophthalmic manifestations, including retinal and optic nerve disorders. The authors describe a case of non-ischaemic central retinal vein occlusion after dengue fever, a phenomenon not previously reported.     

缺血型视网膜中央静脉阻塞的氪离子激光治疗

目的 探讨缺血型视网膜中央静脉阻塞的氪离子激光治疗的疗效.方法 回顾性分析我院应用氪激光全视网膜光凝治疗的缺血型中央静脉阻塞102眼的临床资料.结果 102眼缺血型视网膜中央静脉阻塞中73眼有效,占71.56%;27眼好转,占26.47%;2眼因玻璃体出血,继发新生血管性青光眼或并发白内障失明而无效,占1.97%.结论 对于缺血型视网膜中央静脉阻塞的患者应尽早实行全视网膜光凝术治疗,确保有效光斑的总数与密度是全视网膜光凝术成功的关键.     

Massive Macular Hard Exudates Associated with Branch Retinal Vein Occlusion

Purpose

To report four cases of branch retinal vein occlusion (BRVO) with the complication of serous retinal detachment (SRD).

Methods

We retrospectively studied four eyes of four patients with macular edema and macular hard exudates associated with midperipheral BRVO. Visual acuity, ophthalmoscopy, fluorescein angiography, and optical coherence tomography findings were evaluated. Three of the four eyes underwent laser photocoagulation in the BRVO area 1 month after the initial visit.

Results

Macular edema consisted of SRD without cystoid macular edema in all eyes. Late-phase fluorescein angiography showed extensive dye leakage in the BRVO area. When SRD was resolved 4 months after the initial examination, hard exudates had increased in the macular area. Although macular hard exudates decreased 1 year after the initial examination, visual acuity remained under 20/20 because of macular atrophy.

Conclusions

SRD is one type of macular edema observed in BRVO. In macula-spared midperipheral BRVO, the SRD originates from a vascular leaking area, and there is a high risk that massive macular hard exudates will develop, which may affect visual recovery. Jpn J Ophthalmol 2005;49:527–529© Japanese Ophthalmological Society 2005     

视网膜静脉阻塞血液流变学研究

对30例视网膜静脉阻塞（RVO）患者作了血液流变学检查，以性别、年龄作了配对比较，并根据眼底荧光血管造影图像中有无毛细血管无灌注区及临床表现的严重程度分组，发现RVO病人组校对照组的血液粘度增高，红细胞变形性降低、高血脂合并高血粘度在本组中占63％，血液流变学各项指标增高程度与有无毛细血管无灌注无关。说明血液流变学改变是RVO的重要原因，但其程度与RVO的严重程度无关。高血脂可能为RVO血液粘度增高的原因之一，是RVO血液粘度增高的并存因素。