Cases Of Central Retinal Vein Occlusion Research Articles

In vivo measurement of T1 in the vitreous humor of patients with ischemic retinal disease.

To demonstrate MR T1 mapping in vivo as a method to non-invasively estimate vitreous oxygen concentration in ischemic eye disease. Patients with ischemic eye disease (central retinal vein occlusion, ocular ischemic syndrome, and proliferative diabetic retinopathy) were prospectively recruited. MRI was performed on each patient before any treatment, with T1 mapping acquired using an inversion recovery TrueFISP sequence at several inversion times, from a single slice positioned through the center of both eyes in the axial oblique plane. A phantom study measuring seven different concentrations of vitronectin, a protein released in ischemic eye disease, was undertaken to determine its potential confounding effect on T1 . Ten participants were recruited (eight central retinal vein occlusion, one ocular ischemic syndrome, and one proliferative diabetic retinopathy). Of the eight central retinal vein occlusion cases, there was a statistically different vitreous T1 in the diseased eye compared to the healthy control eye (4.306 vs. 4.518 s, p = 0.008). T1 times did not significantly alter across the range of vitronectin concentrations. Ischemic eye disease decreases vitreous T1 , potentially implying an increase in vitreous partial pressure of oxygen (pO2 ) concentration given what is known from the relationship between 1/T1 and pO2 . Potential theories for this unexpected result are discussed. This study provides further data on this technique, with potential clinical application in eye disease.

Intravitreal Injection of Anti-Vascular Endothelial Growth Factors Combined with Corticosteroids for the Treatment of Macular Edema Secondary to Retinal Vein Occlusion: A Systematic Review and Meta-Analysis

ABSTRACT Purpose To evaluate the efficacy and safety of intravitreal anti-vascular endothelial growth factor (anti-VEGF) and corticosteroid combination therapy for the management of treatment-naïve or recurrent/refractory macular edema caused by retinal vein occlusion (RVO) in comparison with anti-VEGF monotherapy. Methods In this systematic review and meta-analysis study, the data from publications in the electronic databases including PubMed, Embase, Cochrane Library Central Register of Controlled Trials, ISI and Scopus from January 1, 2007, through November 20, 2020, were compiled. Heterogeneity was statistically quantified by the I2 statistic, and meta-analysis was performed using a random-effects model. Results Twenty-four related studies were identified, including a total of 1280 eyes, which consisted of 685 and 507 patients with central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO), respectively. This study demonstrated a greater improvement in best-corrected visual acuity (BCVA) in the combination group compared to anti-VEGF monotherapy for both CRVO and BRVO cases at 6 months after initiating therapy. The improvement in vision was more notable in BRVO cases than in CRVO cases. However, the changes in central macular thickness (CMT) did not differ significantly between the different treatment approaches, and the results were inconclusive. Including all cases with RVO, there was no inferiority in terms of BCVA improvement and CMT reduction in the triamcinolone subgroup compared with the slow-release dexamethasone implant subgroup. A greater improvement was noticed in terms of BCVA in the sequentially treated subgroup compared to the simultaneous treatment subgroup, while there was a greater reduction in CMT in the simultaneous subgroup with the highest reduction recorded at 1 month after treatment. Conclusions This study suggests that combination therapy with intravitreal anti-VEGF and corticosteroid (such as intravitreal or subtenon triamcinolone or dexamethasone implant) has a slightly better effect on improving BCVA in cases with BRVO or CRVO at 6 months compared to monotherapy.

Study of Optic Disc and Macular Vascularity in Central Retinal Vein Occlusion Using Optical Coherence Tomography Angiography

Background Retinal vein occlusion (RVO) is a sight threatening disease. It is the second most common vascular retinal disease after diabetic retinopathy. Central retinal vein occlusion (CRVO) is considered as the most dreadful form, with prevalence of nearly 1 in 1000 in the population aged ≥30 years. Aim of the Work To quantify changes in optic disc and macular vasculature in patients with CRVO using optical coherence tomography angiography. Patients and Methods In our study, we included 20 eyes of twenty patients with treatment naïve cases of CRVO. These cases were selected from the outpatient clinic at Ain shams University Hospital between January 2020 and October 2021. Included subjects were patients diagnosed with CRVO, who received no previous treatment neither by injection nor by laser. Only patients with media opacity that are dense enough to impede sufficient image quality for reliable interpretation were excluded. Results Our study was able to prove the agreement between the quantitative vessel density (VD) measurement in the macula and the current fundus fluorescein angiography (FFA) based assessment of macular ischemia. We were able to confirm a deep component to the pathological process in CRVO as proposed by the current literature and be able to assess it simultaneously in relation to the superficial microcirculation using optical coherence tomography angiography (OCTA) and FFA. We found the optic disc VD parameters to be a significant indicator of global retina perfusion which could be of value in assessment and follow up of patients especially in the presence of confounding factors for macular VD measurement as extensive edema. We found significant correlation between FAZ size and measured macular vessel density indicating congruity of the two ischemic parameters. Conclusion OCTA is a new modality for retinal imaging, providing a noninvasive alternative for the gold standard FFA. It visualizes microvascular changes in cases of vascular diseases at least with the same sensitivity as FFA. It has the definite advantage of being easily repeated in case of poor quality and patients who needs recurrent follow up imaging. It can be also used in patients who don’t qualify for or with contraindications to FFA. However, OCTA is liable to inaccuracy due to inherent disadvantages as segmentation and projection artifacts.

Deep Capillary Plexus as Biomarker of Peripheral Capillary Nonperfusion in Central Retinal Vein Occlusion.

To identify the vascular biomarkers of peripheral capillary nonperfusion in patients affected by naive central retinal vein occlusion (CRVO), and to analyze their changes over the follow-up. Consecutive prospective case series with a planned follow-up of 2years. Thirty-five patients affected by CRVO and 35 healthy gender- and age-matched subjects were enrolled in the study. Ophthalmic examination included best corrected visual acuity (BCVA), ultrawidefield fluorescein angiography (UWFFA), OCT, and OCT angiography (OCTA). Vessel density (VD) at the superficial capillary plexus and deep capillary plexus (DCP) were calculated on OCTA images. The ischemic index (ISI) was calculated on UWFFA. The mean baseline ISI was 37%, increasing to 40% at the end of the follow-up, whereas it was 4.9% in the patients' fellow eyes and 4.5% in the control group with no change over the follow-up. OCT angiography revealed VD reduction in the DCP, considering both 3×3 mm and 12×12 mm scans. The correlation analyses revealed that DCP VD was the only parameter showing a statistically significant correlation with the foveal avascular zone (FAZ) area, BCVA, and ISI. Deep capillary plexus VD impairment is detectable in all CRVO cases, variably involving both the central retina (with enlarged FAZ) and the periphery (with VD reduction in the peripheral retina). The severity of DCP VD reduction has correlates with various clinical markers. Deep capillary plexus VD may represent a crucial biomarker to characterize CRVO, and further studies are necessary to identify the cutoff thresholds for the different clinicalmanifestations.

TO ASSESS REDUCTION IN MACULAR EDEMA BY SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY (SD-OCT) FOLLOWING INJECTION OF BEVACIZUMAB IN CASES OF CENTRAL RETINAL VEIN OCCLUSION (CRVO)

Aim: To study the reduction in macular oedema in Central Retinal Vein Occlusion cases following Intravitreal injection of Bevacizumab using Spectral Domain Optical Coherence Tomography. Methods: 50 patients diagnosed with Central Retinal Vein Occlusion with macular oedema of more than 300 microns on Spectral Domain Optical Coherence Tomography ( SD-OCT) ,who attended to Out patient Department of Government Regional Eye Hospital (GREH) between January 2020 to June 2020 were administered Intravitreal Injection of Bevacizumab (Avastin) 1.25mg in 0.05ml. Re-injections were given if SD-OCT showed persistence of macular oedema. In follow up visits, patients were evaluated with SD-OCT and Central macular thickness (CMT) was measured every month till 6 months from the date of first injection. Results: Out of 50 cases included in the study, there was reduction in macular oedema in 45 (90%) cases and 5% had persistence of macular edema. Conclusion: Intravitreal Bevacizumab is a safe and effective modality of treatment for reducing macular edema due to Central Retinal Vein Occlusion as per our study.

Retinal Microvascular Resistance Estimated from Waveform Analysis Is Significantly Higher With a Threshold Value in Central Retinal Vein Occlusion.

PurposeEvaluation of blood flow is useful for understanding the severity of central retinal vein occlusion (CRVO). Actual blood flow may be determined by the resistivity of the retinal vein in CRVO. We have previously evaluated mean blur rate (MBR) to reflect total retinal blood flow velocity in CRVO cases using laser speckle flowgraphy (LSFG). This study evaluated retinal total vascular resistance in CRVO cases using the new index of total capillary resistance (TCR) from LSFG.MethodsWe measured the TCR of 68 CRVO patients who visited Nagasaki University Hospital between 2009 and 2016 and 42 age-matched controls without systemic disease. We compared TCRs among control eyes, CRVO fellow eyes, and CRVO affected eyes. A CRVO threshold value was then obtained from the receiver operating characteristic curve.ResultsMBR was significantly lower for CRVO affected eyes (20.3 ± 8.2) than for control eyes (37.5 ± 8.4; P < 0.01) and CRVO fellow eyes (36.4 ± 10.0; P < 0.01, Dunn's test). TCR was significantly higher for CRVO affected eyes (1.20 ± 0.55) than for control eyes (0.68 ± 0.2; P < 0.01) and CRVO fellow eyes (0.81 ± 0.28; P < 0.01, Dunn's test). The threshold for the presence of CRVO was 0.93 and area under the curve was 0.84.ConclusionsBy measuring TCR in addition to MBR, more detailed information regarding CRVO pathology can be obtained.Translational RelevanceComparison of values before and after treatment may be useful for evaluating the effects of treatment.

Efficacy and safety of dexamethasone intravitreal implant in patients with retinal vein occlusion resistant to anti-VEGF therapy: a 12-month prospective study

Purpose: To evaluate the safety and efficacy of repeated intravitreal dexamethasone implant (Ozurdex) injections administrated on an “as-needed” protocol for retinal vein occlusion patients with macular oedema, previously subjected to at least five anti-vascular endothelial growth factor (VEGF) injections with poor or no response.Methods: Prospective interventional case series of 13 branch retinal vein occlusion (BRVO) and 10 central retinal vein occlusion (CRVO) patients with persistent macular oedema (>250 μm) after at least five anti-VEGF injections. Exclusion criteria included: baseline visual acuity worse than 1.5 logMAR, previous intravitreal implant, history of vitreoretinal surgery, manifest glaucoma or ocular hypertension, epiretinal membrane, retinal neovascularization, massive retinal or macular ischaemia, vitreous haemorrhage or severe lens opacity, previous laser photocoagulation treatment. Each patient received an initial intraocular dexamethasone implant and the procedure was repeated at 6 months “as needed.” Patients were followed up at months 2, 4, 6, 8, 10 and 12 with spectral domain optical coherence tomography and best corrected visual acuity measurements. Exclusion criteria included: baseline visual acuity worse than 1.5 logMAR, previous intravitreal implant, history of vitreoretinal surgery, manifest glaucoma or ocular hypertension, epiretinal membrane, retinal neovascularization, retinal or macular ischaemia, vitreous haemorrhage or severe lens opacity, previous laser photocoagulation treatment. Patients on topical or systemic corticosteroid therapy (during the last 3 months), and known steroid responders as well as diabetic patients were also excluded.Results: In the BRVO group, the mean central retinal thickness (CRT) and best corrected visual acuity (BCVA) significantly improved from 482.92 ± 139.99 μm (0.55 ± 0.12 logMAR) at baseline, to 369.31 ± 119.72 μm (0.43 ± 0.18 logMAR) at 6 months (p = 0.011/p = 0.019). At 12 months CRT was 295.82 ± 135.48 μm (p = 0.026) and BCVA 0.29 ± 0.17 logMAR (p = 0.002). Minimum CRT values were achieved at 3.45 months after the first injection, and 2.46 months after the second injection (197.00 ± 84.27 and 180.00 ± 76.89 μm, respectively). Best BCVA values were achieved at a mean of 4 ± 0.853 months after the first injection, and 4 months after the second injection (0.219 ± 0.129 and 0.222 ± 0.078 logMAR, respectively). In the CRVO group, neither the mean CRT nor BCVA improved significantly at 6 months: from 669.70 ± 203.20 μm (0.80 ± 0.231 logMAR) at baseline, to 586.20 ± 237.63 μm (0.740 ± 0.268 logMAR) at 6 months (p = 0.131/p = 0.333). At 12 months CRT was significantly improved: 549.90 ± 191.26 μm (p = 0.047), but BCVA lacked significant improvement: 0.690 ± 0.285 logMAR (p = 0.072). Minimum CRT values were achieved at a mean of 2 months after the first injection, and also 2 months after the second injection (261.60 ± 121.31 and 280.00 ± 177.43 μm, respectively). Best BCVA values were achieved at a mean of 2 months after the first injection, and 2 months after the second injection and were 0.390 ± 0.173 and 0.385 ± 0.233 logMAR, respectively. Cataract progression was a rare event (2/23 eyes), while transient steroid-induced ocular hypertension (5/23 eyes) was managed successfully with IOP-lowering medicationConclusion: Dexamethasone implant should be considered as an effective and safe alternative in patients with BRVO and CRVO who have failed anti-VEGF therapy. Shortening the re-injection interval especially for CRVO cases should be considered.

Anti-Vascular Endothelial Growth Factor (Anti-VEGF) in Central Retinal Vein Occlusion : Are Loading Dose Necessary ?

&#x0D; &#x0D; &#x0D; Background : Ranibizumab (anti-VEGF) given monthly for six doses, is effective in central retinal vein occlusion (CRVO). However, the cost and adherence to complete Ranibizumab regiment is a burden for developing countries. Aim : To present two CRVO cases with satisfactory outcome after partial regiment of ranibizumab injections. &#x0D; Case presentation : A 52-year old male came with sudden, painless visual decline of the left eye (LE). Best corrected visual acuity (BCVA) was 0.4. Relative afferent pupillary defect (RAPD) was positive on LE. Anterior segment was normal. Fundus examination revealed a cup-disc ratio (CDR) of 0.4, macular edema (ME), scattered hemorrhages, dilated and tortuous retinal veins. Patient was diagnosed with CRVO and was given two monthly injections before stopping treatment. Patient came with worsened VA, was then given another injection. After 6 months, his BCVA was 0.8. Similarly, a 32- year old male came with sudden painless decline of vision of LE (BCVA 0.15). Anterior segment was normal. Fundus examination showed CDR of 0.3, ME, multiple scattered pre-retinal hemorrhages, dilated and tortuous retinal veins. Patient was similarly diagnosed with CRVO of LE and given two monthly injections. Final BCVA after six months follow-up was 0.9. &#x0D; Conclusion : Both cases showed improvement in VA despite having partial regiment of ranibizumab injections. &#x0D; &#x0D; &#x0D;

Efficacy of panretinal laser in ischemic central retinal vein occlusion: A systematic review.

The aim of the present systematic review was to assess the efficacy of laser therapy for ischemic central retinal vein occlusion (CRVO). Relevant studies were retrieved by searching the PubMed, Embase, Chinese Biomedical Literature Database and, Chinese Science and Technology Periodicals databases using a combination of key words, including 'central retinal vein obstruction', 'CRVO', 'laser' and 'panretinal photocoagulation'. The titles, abstracts and full texts were screened by two independent reviewers and studies were selected according to specific inclusion criteria. Data were extracted and the quality of each study was graded using the Grading of Recommendations, Assessment, Development and Evaluation or Methodological Index for Non-Randomized Studies (MINORS) criteria. A total of 1,187 abstracts were retrieved, and finally, 11 clinical studies were selected, including 534 cases of CRVO. Of these, 8 studies compared the efficacy of laser therapy with other treatments for CRVO, two studies compared the efficacy of laser therapy and drug treatment for CRVO and one study compared the efficacy of early laser therapy with standard laser therapy (regular examinations and laser therapy performed as soon as neovascularization was identified) for CRVO. Among them, the results of five studies demonstrated that panretinal photocoagulation (PRP) for the prevention of iris neovascularization and neovascular glaucoma is inefficient regarding the improvement of visual acuity. A total of 10 studies indicated that laser therapy achieved better outcomes in neovascularization of the retina, optic disc neovascularization and iris neovascularization, neovascular glaucoma, vitreous hemorrhage, changes in the visual field, macular edema, macular thickness and intraocular pressure. Of note, it was indicated that laser photocoagulation prevents the severe vascular complications of CRVO. In addition, in the eyes of patients receiving PRP for the treatment of ischemic CRVO, significant reductions in corneal sub-basal nerve plexus parameters and average peripapillary retinal nerve fiber layer thickness were observed. Furthermore, laser photocoagulation was able to increase retinal blood flow in eyes with ischemic CRVO.

Unilateral central retinal vein occlusion as a first manifestation of diabetes mellitus in a ten-year-old girl

Central retinal vein occlusion (CRVO) is relatively rare in the pediatric age group. We present a case of CRVO as the first manifestation of diabetes mellitus in a ten-year-old girl. The associated macular edema was managed successfully with a single injection of Ranibizumab. Ophthalmologists should consider the possibility of diabetes mellitus in pediatric cases of CRVO.

Optical coherence tomography angiography in retinal vein occlusion treated with dexamethasone implant: a new test for follow-up evaluation.

To quantitatively and qualitatively analyze patients with macular edema secondary to retinal vein occlusion (RVO) and treated with the intravitreal dexamethasone implant using optical coherence tomography angiography (OCTA). The files of patients treated with intravitreal injection of dexamethasone implant for macular edema secondary to RVO were retrospectively analyzed. Before and after injection, the following data were recorded: best-corrected visual acuity (BCVA), central macular thickness (CMT) measured using spectral-domain optical coherence tomography, fluorescein angiography, and OCTA (Optovue, Inc., Fremont, CA, USA). Results of automatic measurement of vascular density of the superficial capillary plexus (SCP) and deep capillary plexus were obtained before and after treatment and compared to those of healthy subjects matched for age and sex. Seven eyes of 7 patients (mean age, 76 years; 57% male) were analyzed, including 3 cases of central RVO and 4 cases of branch RVO. All patients received 1 intravitreal injection of dexamethasone implant. After a mean follow-up of 2 months, CMT significantly decreased from 657 µm to 324 µm on average and BCVA increased from 20/100 to 20/50 (p = 0.017 and p&lt;0.001, respectively). At the SCP, the mean whole en face vascular density slightly decreased during follow-up from 43.21% to 42.76% (not statistically significant). Vascular densities were largely inferior to those observed in control subjects (p≤0.01 in all quadrants). This study confirms the potential contribution of OCTA as a novel noninvasive imaging technology that enables a quantitative and qualitative evaluation of the follow-up of macular edema in RVO. Optical coherence tomography angiography may complement advantageously multimodal imaging to monitor patients with RVO.

Vitamin D Deficiency in Patients with Central Retinal Vein Occlusion: A Case Control Study

ABSTRACTPurpose: Central retinal vein occlusion (CRVO) has been shown to occur more often in winter/spring season. We aimed to evaluate if patients with CRVO have more vitamin D deficiency compared to matched controls.Methods: Prospective match controlled study of 72 patients with CRVO and 144 matched controls. All new CRVO cases presenting at St. Erik Eye Hospital, Stockholm, Sweden during the study period were approached to participate. Statistics Sweden provided randomly selected controls matched for age, gender, and season. The first 18 cases of CRVO and 36 controls for each of the four seasons were included and blood was drawn for 25-OH vitamin D analysis (25(OH)D).Results: About half of the patients (51.4%) in the CRVO group had vitamin D deficiency [25(OH)D < 50 nmol/l] as compared to 39.3% in the control group [odds ratio 1.64, 95% confidence interval (CI) 0.91–2.94]. The mean concentrations of serum 25(OH)D were 55.3 nmol/l (95% CI 48.4–62.2) in the study group and 59.8 nmol/l (95% CI 55.4–64.2) in the control group (p = 0.28). In stratified analysis, the CRVO patients under 75 years had significantly lower 25(OH)D levels than the matched controls (47.8 nmol/l vs. 59.0 nmol/l, p = 0.02).Conclusions: Vitamin D deficiency is common in patients with CRVO. No significant differences in vitamin deficiency or 25(OH)D levels were found in comparison to the control group. However, the CRVO patients under 75 years had significantly lower 25(OH)D levels as compared to the control group.

Homocysteine induces oxidative stress in young adult central retinal vein occlusion

ObjectivesHigh levels of plasma homocysteine have been reported to be toxic to the vascular endothelium, thereby creating an environment of hypercoagulability and occlusion. Elevated homocysteine has been reported as a...

Thrombophilia and retinal vascular occlusion

PurposeThe purpose of this research was to assess associations of thrombophilia with central retinal vein occlusion (CRVO), central retinal artery occlusion (CRAO), and amaurosis fugax (AF); to evaluate outcomes of normalizing high homocysteine; and to study CRVO, CRAO, and AF developing in estrogens/estrogen agonists in women subsequently shown to have thrombophilia.MethodsMeasures of thrombophilia–hypofibrinolysis were obtained in 132 CRVO cases, 15 CRAO cases, and 17 AF cases. Cases were compared to 105 healthy control subjects who did not differ by race or sex and were free of any ophthalmologic disorders. All cardiovascular disease (CVD) risk factors were compared to healthy general populations.Main outcome measuresThe main outcome measure of this study was thrombophilia.ResultsCRVO cases were more likely than controls to have high homocysteine (odds ratio [OR] 8.64, 95% confidence intervals [CI]: 1.96–38), high anticardiolipin immunoglobulin M (IgM; OR 6.26, 95% CI: 1.4–28.2), and high Factor VIII (OR 2.47, 95% CI: 1.31–7.9). CRAO-AF cases were more likely than controls to have high homocysteine (OR 14, 95% CI: 2.7–71.6) or the lupus anticoagulant (OR 4.1, 95% CI: 1.3–13.2). In four of 77 women with CRVO (two found to have high homocysteine, two with inherited high Factor XI), CRVO occurred after starting estrogen–progestins, estrogen–testosterone, or estrogen agonists. In one of eight women with CRAO found to have high anticardiolipin antibody IgG, CRAO occurred after starting conjugated estrogens, and AF occurred after starting conjugated estrogens in one of eleven women with AF (inherited protein S deficiency). Therapy for medians of 21 months (CRVO) and 6 months (CRAO-AF) was 5 mg folic acid, 100 mg B6, and 2000 mcg/day B12 normalized homocysteine in 13 of 16 (81%) CRVO cases and all five CRAO-AF cases with pretreatment hyperhomocysteinemia. The CRVO cases had an excess of hypertension; CRAO-AF cases had an excess of type 2 diabetes and hypertension.ConclusionTreatable thrombophilia, hyperhomocysteinemia in particular, is more common in RVO cases than in normal controls. RVO occurs after estrogens or estrogen agonists were administered in women subsequently shown to have thrombophilia.

Surgical macular decompression for macular edema in retinal vein occlusion.

Recently, a number of surgical and laser approaches have been used to improve visual outcome in cases of central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO). Intravitreal steroid injection alone appears to offer only temporary improvement at best. Radial optic neurotomy for CRVO and arteriovenous adventitial sheathotomy for BRVO are the most frequently utilized surgical procedures for these conditions, but evidence regarding efficacy is still lacking. We have suggested that macular decompression by internal limiting membrane (ILM) peeling may reduce macular edema and hemorrhage and improve visual acuity by relieving elevated intraretinal tissue pressure and facilitating egress of blood and extracellular fluid out of inner retinal layers into the vitrectomized vitreous cavity. 50 cases of severe visual loss due to macular edema caused by CRVO or BRVO, not eligible for laser photocoagulation, underwent pars plana vitrectomy with removal of preretinal hyaloid, peeling of the ILM stained with indocyanine green dye, air-fluid exchange, and postoperative prone positioning. In all cases, intraretinal blood and retinal thickening diminished within 6 weeks of surgery. Visual acuity improved in 87% of CRVO cases and 68% of BRVO cases. Vision improved and stabilized at 39 days after surgery. Average improvement was 2.6 lines with a 6-line improvement in 1 case. There was no difference in outcome between cases with ischemic or nonischemic features on fluorescein angiography. Macular decompression using vitrectomy and ILM peeling is effective in the treatment of severe visual loss due to macular edema in CRVO and in those BRVO cases that do not qualify for laser photocoagulation.

Pars plana vitrectomy and internal limiting membrane peeling for macular edema secondary to retinal vein occlusion

Purpose:To evaluate the effects of vitrectomy and internal limiting membrane peeling for treatment of macular edema secondary to retinal vein occlusion (RVO).Methods:Nine cases of visual loss due to macular edema caused by central retinal vein occlusion or branch retinal vein occlusion underwent pars plana vitrectomy with removal of the preretinal hyaloid, peeling of the internal limiting membrane stained with indocyanine green dye, air–fluid exchange, and postoperative prone positioning. Best-corrected visual acuity (BCVA) and central foveal thickness by optical coherence tomography were measured pre- and postoperatively then compared to assess the outcome of surgery.Results:In all cases intraretinal blood and retinal thickening diminished within 2 months of surgery. Visual acuity improved in all of the central retinal vein occlusion cases and 3/6 branch retinal vein occlusion cases. The decrease in macular thickness was statistically significant (mean postoperative macular thickness 361 ± 61.1 versus mean preoperative macular thickness 563.9 ± 90.0, P = 0.001, t-test). The improvement in BCVA was not statistically significant (mean preoperative BCVA in LogMAR 1.23 ± 0.29 versus mean postoperative BCVA in LogMAR 1.06 ± 0.49, P = 0.09, t-test).Conclusion:In eyes with macular edema secondary to RVO, pars plana vitrectomy with internal limiting membrane peeling can resolve macular edema, but the improvement in BCVA was not statistically significant in this study.

Natural History of Central Retinal Vein Occlusion: An Evidence-Based Systematic Review

To describe the natural history of central retinal vein occlusion (CRVO) based on the best available evidence from the literature. Central retinal vein occlusion is a common sight-threatening retinal vascular disease. Despite the introduction of new interventions, the natural history of CRVO is unclear. Systemic review of all English language articles retrieved using a keyword search of MEDLINE, EMBASE, Current Contents, and the Cochrane Library to November 13, 2008. This was supplemented by hand-searching references of review articles published within the last 5 years. Two investigators independently identified all relevant observational studies evaluating the natural history of RVO and all clinical trials evaluating interventions for CRVO; an untreated control arm was included. Of 5966 citations retrieved, 53 studies were reviewed, providing 3271 eyes with CRVO for analysis of its natural history. Visual acuity (VA) was generally poor at baseline (<20/40) and decreased further over time. Although 6 studies reported an improvement in VA, none of these improvements resulted in VA better than 20/40. Up to 34% of eyes with nonischemic CRVO converted to ischemic CRVO over a 3-year period. In ischemic CRVO cases, neovascular glaucoma developed in at least 23% of eyes within 15 months. In nonischemic CRVO cases, macular edema resolved in approximately 30% of eyes over time, and subsequent neovascular glaucoma was rare. Untreated eyes with CRVO generally had poor VA, which declined further over time. One quarter of eyes with nonischemic CRVO converted to ischemic CRVO.

Effet de l’hémodilution isovolémique dans le traitement de la phase aiguë des occlusions de la veine centrale de la rétine : une étude pilote

Cases series and randomized studies support the use of isovolumic hemodilution at the acute phase of the central retinal vein occlusion (CRVO). However, a recent meta-analysis showed the difficulty of interpreting the long-term effect of isovolumic hemodilution because of the late complications and the concomitant use of other treatments. We present here a pilot case-series study aiming to demonstrate the effect of isovolumic hemodilution at the acute phase of the disease, before any other treatment was applied. Twenty-two consecutive cases of CRVO were prospectively treated with isovolumic hemodilution within 15 days of disease onset (substitution of 10 ml/kg of blood by a macromolecular solution (Voluven), aiming at a hematocrit of 35%). The treatment was performed in ambulatory conditions after excluding common contraindications (cardiac, respiratory and renal insufficiency, angina pectoris, history of heart attack or stroke during the last 6 months). The patients were followed prospectively with respect to visual acuity, fluorescein angiography and visual acuity at one week, one month, three months and twelve months. Visual acuity improved of at least one ETDRS line (5 letters) in 59% of the patients one week after the treatment. Improvement in the haemodynamic was observed in all these cases on fluorescein angiography. The vision remained stable at 1 month and 3 months before any other treatment was applied. After the 3rd month, additional intravitreous injection of triamcinolone was applied in 32% of eyes for persistent macular edema. At 12 months after hemodilution, visual acuity improved in 64% of cases and only 5% of the eyes converted into an ischemic CRVO. Isovolumic hemodilution at the acute phase of the CRVO is followed by an improvement in both vision and angiographic characteristics in more than 60% of our patients and the conversion into an ischemic form was limited to 5% of eyes. Further randomized studies are needed to evaluate the specific effect of hemodilution in the long term.

Ischaemic change after intravitreal bevacizumab (Avastin®) injection for macular oedema secondary to non‐ischaemic central retinal vein occlusion

Editor, A 65-year-old male patient with a 12-year history of diabetes presented with decreased visual acuity in his right eye of 3 months duration. Best-corrected visual acuity (BCVA) was 0.4 in the right eye (RE) and 1.0 in the left eye (LE). A slit-lamp examination showed grade two bilateral nucleosclerosis with no further abnormalities of the anterior segment. Fundus examination and fluorescein angiography showed flame-shaped retinal haemorrhages in four quadrants and optocillary shunt vessels. These ocular findings were consistent with non-ischaemic central retinal vein occlusion (CRVO). Optical coherence tomography (OCT) showed submacular fluid and macular elevation with a central macular thickness of 533 μm in the RE (Fig. 1). An intravitreal off-label bevacizumab injection was recommended. The patient was informed about the treatment beforehand and provided written informed consent. The injection was performed in a sterile setting and prophylactic topical antibiotics and carbonic anhydrase inhibitor were given for 1 week pre- and post-injection. The intravitreal dosage of bevacizumab was 1.25 mg (0.05 ml). Repeat examinations of visual acuity, intraocular pressure and fundus examinations were scheduled at 1 day, 1 week and 1 month after injection. Three weeks after injection, the patient reported a deterioration of visual acuity in the RE. His visual acuity in the RE was 0.02 and a fundus examination showed disc oedema with extensive flame-shaped retinal haemorrhages in the four retinal quadrants (Fig. 2). A fluorescein angiogram of the RE demonstrated severe non-perfusion including the fovea with blocked hypofluorescence. OCT imaging showed a central macular thickness of 560 μm (Fig. 2). Six months after the injection, his visual acuity in the RE was 0.02 and panretinal photocoagulation was performed. Fundus photography (A), fluorescein angiography (B) and optical coherence tomography (OCT) (C) images at initial presentation. (A) Fundus photograph showing multiple intraretinal haemorrhages and dilated retinal veins with optociliary shunt vessels. (B) Fluorescein angiograph in the late phase showing blocked hypofluorescence with patelloid pattern of dye leakage in the fovea in the right eye. (C) A vertical OCT image of the right eye showing cystoid macular oedema with a central macular thickness of 533 μm. Fundus photography (A), fluorescein angiography (B) and optical coherence tomography (OCT) (C) images 3 weeks after intravitreal bevacizumab administration. (A) Fundus photograph showing extensive flame-shaped retinal haemorrhages and disc swelling. (B) Fluorescein angiograph in the late phase showing severe non-perfusion and dye leakage at the optic disc. (C) Vertical OCT image showing subretinal fluid with a central macular thickness of 560 μm. Bevacizumab represents a new treatment option for early intervention against the formation of macular oedema in various disease conditions. Several short-term results have been published on intravitreal bevacizumab for macular oedema secondary to retinal vein occlusion with CRVO (Iturralde et al. 2006; Spandau et al. 2006; Pai et al. 2007). These reports suggest that intravitreal bevacizumab may reduce macular oedema and increase visual acuity in CRVO. But because a physiological level of vascular endothelial growth factor (VEGF) may be necessary for retinal homeostasis, precautions may have to be taken to avoid the possible negative effects of a complete blockade of VEGF, particularly in primarily ischaemic diseases. However, no report has been issued regarding complications associated with intravitreal bevacizumab except for endophthalmitis. Here, we present a case of non-ischaemic CRVO conversion to ischaemic CRVO after injecting bevacizumab intravitreally. The formation of a new blood flow balance is presumably supported by the formation of collateral vessels with a new drainage route. Spandau et al. (2006) suggested the possibility of complete blockage of VEGF by intravitreal bevacizumab. Although 11–34% of non-ischaemic CRVO cases convert to ischaemic CRVO over a natural course of 3–5 years, we suggest that intravitreal bevacizumab injection affected the outcome in this case (TCVOS 1997). This is because ischaemic CRVO occurred 3 weeks after the injection, when bevacizumab has its peak effect and relatively good initial visual acuity and perfusion status. There were no other patient factors that might cause the ischaemic conversion of CRVO except diabetes. The causes and mechanisms of treatment failure associated with bevacizumab administration must be elucidated further in vitro and by clinical studies. Furthermore, the possibility that bevacizumab has a negative long-term effect on collateral vessel formation because of its anti-VEGF action requires investigation.

Prevalence and risk factors of retinal vein occlusion in an Asian population

Aim:To describe the prevalence and risk factors of retinal vein occlusion (RVO) in an Asian population.Methods:The Singapore Malay Eye Study is a population-based, cross-sectional study of 3280 (78.7%) Malay adults...