A randomised prospective study of outpatient haemodilution for central retinal vein obstruction

Hemodilution therapy using automated erythrocytapheresis in central retinal vein occlusion: results of a multicenter randomized controlled study

BACKGROUND

Central retinal vein occlusion (CRVO) leads to poor visual outcome in most eyes. Abnormal hemorheology was suspected to play a major role in its pathogenesis. CRVO treatment is still a matter of debate but several studies have pointed out the efficacy of isovolumic hemodilution. The aim of this study was to assess the feasibility and efficacy of hemodilution using automated erythrocytapheresis in recent-onset CRVO.

METHODS

In this prospective randomized controlled multicenter study, 61 consecutive CRVO patients were enrolled when they met the following criteria: CRVO lasting for 3 weeks or less, visual acuity ranging from 20/200 to 20/32, age between 18 and 85 years, no diabetes, no uncontrolled systemic hypertension, no antiplatelet or anticoagulant therapy, hematocrit higher than 38%, and signed informed consent. Patients were randomly assigned to the hemodilution group (n = 31) or to the control group (n = 30). Hemodilution therapy consisted of one session of erythrocytapheresis on outpatient basis, followed by additional session(s) for 6 weeks if needed. Target hematocrit was 35%. Follow-up was 12 months.

RESULTS

No statistical differences in age, associated risk factors, or CRVO characteristics were observed at baseline between both groups. Mean visual acuity was equivalent to 20/80 in the hemodilution group and to 20/63 in the control group (non-significant difference). In the treated group, mean number of hemodilution sessions was 3.3 (range, 1 to 6), and no major side-effects occurred. At the 12-month follow-up visit, 64.5% of the hemodilution group had visual acuity of 20/40 or better compared to 40% of the control group (p = .048). Visual change was a gain of 1.7 ETDRS line in the hemodilution group versus a loss of 2.3 lines in the control group (p = .007). There was less conversion into an ischemic form in the hemodilution group (11%) than in the control group (50%, p = .004). Mean final retinal thickness was 289 μm in the hemodilution group versus 401 μm in the control group (p = .068).

CONCLUSIONS

This multicenter controlled randomized study demonstrated that automated erythrocytapheresis is a safe and effective tool for performing hemodilution and confirmed that hemodilution therapy can improve the final prognosis of CRVO when applied in the early phase of the disease.

Natural history of central retinal vein occlusion: an evidence-based systematic review

OBJECTIVE

To describe the natural history of central retinal vein occlusion (CRVO) based on the best available evidence from the literature.

CLINICAL RELEVANCE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

Untreated eyes with CRVO generally had poor VA, which declined further over time. One quarter of eyes with nonischemic CRVO converted to ischemic CRVO.

[Isovolumic hemodilution in the management of the acute phase of central retinal vein occlusion: a pilot study]

INTRODUCTION

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.

PATIENTS AND METHOD

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.

RESULTS

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.

DISCUSSION

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.

Medical treatment of retinal vein occlusions

The medical treatment of retinal vein occlusion (RVO) is comprised of three main stages: identification and therapy of the detectable risk factors, specific treatment aimed at the occlusive form and treatment of RVO complications. Even though the possible medical management of RVO includes several treatments, the most interesting approaches have been: anticoagulant/antiaggregating agents, troxerutin, corticosteroid, fibrinolytic/thrombolytic agents, and hemodilution. Overall, the medical approach to RVO is still awkward and unsatisfactory. Randomized clinical trials are needed to assess the degree of efficacy of the medical treatment of the specific forms of RVO.

[Treatment of central retinal vein occlusion by isovolemic hemodilution]

PURPOSE

Evaluate the effects of hemodilution in the treatment of central retinal vein occlusion (CRVO).

PATIENTS AND METHODS

We carried out a retrospective, noncomparative study of 25 patients presenting unilateral CRVO, treated with one to three hemodilution sessions. The patients were re-examined in the 1st, 2nd, 3rd, 6th and 12th months following treatment with measurement of visual acuity, fluorescein angiography, and optical coherence tomography.

RESULTS

Our study included 17 men and eight women, averaging 63 years of age (range, 35-87 years), and monitored for an average of 7 months (range, 3-12 months). After the 6th month following treatment, average visual acuity improved compared to initial visual acuity. Initial visual acuity of less than 1/10, with the existence of poorly irrigated areas in the angiography, presented negative prognosis factors. The number of hemodilutions did not produce a significant difference in final visual acuity. No serious complications due to hemodilution were observed.

DISCUSSION

Treatment of CRVO is subject to debate. Some practitioners recommend against treatment, while others advocate intervention and offer laser-induced chorioretinal venous anastomosis. Surgical vitrectomy and radial optical neurotomy, with or without injection of triamcinolone, await evaluation. Hemodilution may offer a therapeutic approach to this pathology, in which the etiopathogenesis is not yet recognized, but in which blood viscosity plays a key role. This treatment is well tolerated.

CONCLUSION

Hemodilutions appear to have beneficial effects in treating CRVO, whatever the number of hemodilutions used. This study should be confirmed by a prospective study using an untreated control group.

Effect of oral pentoxifylline on cystoid macular edema associated with central retinal vein occlusion

PURPOSE

To determine whether oral pentoxifylline, a xanthine-derived hemorheologic agent, decreases cystoid macular edema (CME) and improves visual acuity in eyes with a perfused central retinal vein occlusion (CRVO).

METHODS

Retrospective chart review of consecutive patients on pentoxifylline (400 mg po TID) for CRVO was performed. Inclusion criteria included CME, pentoxifylline use for at least 1 month, and a follow-up period of at least 4 months. Exclusion criteria included nonperfused or indeterminate CRVO, the presence of neovascularization, and previous or concurrent laser therapy or any other treatment for CRVO. Statistical analysis of collected data was performed.

RESULTS

Eleven patients were identified. All patients had a perfused CRVO. The mean best-corrected Early Treatment Diabetic Retinopathy Study visual acuity was 60 letters (Snellen equivalent 20/128) before the initiation of oral pentoxifylline. The mean time from onset of CRVO to start of pentoxifylline therapy was 5 months (range, 1-12 months). The mean duration of pentoxifylline use was 5.3 months (range, 2.5-10.2 months). The mean follow-up period was 8 months (range, 2.7-16.5 months). Cystoid macular edema had improved in 64% (7/11) of eyes at last follow-up as measured by biomicroscopy and optical coherence tomography. The visual acuity was not significantly changed at 62 letters (20/128 +2) (Student t-test, P = 0.7) at last follow-up. There were no significant side effects from pentoxifylline. One patient had mild gastrointestinal disturbance.

CONCLUSION

Pentoxifylline has a favorable adverse effect profile, and can reduce CME in eyes with CRVO. Visual acuity does not appear to change significantly. A larger, randomized, multiarmed clinical trial evaluating the effects of pentoxifylline as an adjunctive treatment modality may be of benefit since even a small positive effect in altering the natural history of CME related to CRVO may be of value for these patients.

[Therapeutic erythrocytapheresis: technical aspects and clinical applications]

PURPOSE

Therapeutic erythrocytapheresis is a selective red cell-depletion aphaeresis technique.

CURRENT KNOWLEDGE AND KEY POINT

Using a discontinuous or continuous flow blood cell separator, the technique safely allows quickly and automatically collecting a large volume of red cells. The main obstacle of implementation is a poor peripheral venous access. The procedure is well-tolerated. Polycythemia vera, hereditary hemochromatosis, complicated sickle-cell-disease and retinal venous occlusion are the main clinical applications.

PROSPECT AND PROJECT

Therapeutic erythrocytapheresis is a more modern and more effective method than the classic patient-bleeding. It has to be preferred in the early treatment of patients with polycythemia vera and hereditary hemochromatosis.

Interventions for Central Retinal Vein Occlusion

TOPIC

To assess the evidence for the effectiveness of interventions to improve visual acuity (VA) and prevent or treat neovascularization secondary to central retinal vein occlusion (CRVO).

CLINICAL RELEVANCE

Central retinal vein occlusion is a common cause of visual morbidity and blindness. Many different interventions have been advocated, but the evidence justifying their use remains unclear.

METHODS/LITERATURE REVIEWED

English and non-English language articles were retrieved using a keyword search of Medline (1966 onwards), Embase, the Cochrane Collaboration, the National Institutes of Health Clinical Trials database, and the Association for Research in Vision and Ophthalmology (2003-2005). This was supplemented by manually searching references of review articles. Two investigators independently identified all randomized clinical trials (RCTs) on interventions in CRVO with more than 3 months' follow-up.

RESULTS

Of 4133 citations retrieved, 17 RCTs comparing intervention with a control group were identified. There were 4 RCTs on laser photocoagulation. Grid macular laser photocoagulation did not improve VA in CRVO with macular edema. Prophylactic panretinal photocoagulation did not prevent angle and iris neovascularization in ischemic CRVO, but resulted in regression of angle and iris neovascularization and reduced progression to neovascular glaucoma. There were 4 RCTs that reported improvement in VA with inpatient hemodilution, 2 RCTs with no significant improvement, and 1 RCT showing deterioration in VA after outpatient hemodilution. Randomized clinical trials evaluating ticlodipine, troxerutin, and streptokinase showed a limited or no benefit.

CONCLUSIONS

This review found limited level I evidence for any intervention to improve VA in patients with CRVO. Panretinal photocoagulation resulted in regression of neovascularization. Hemodilution may improve vision in some patients, but the data conflict. More robust randomized controlled trials evaluating current treatments for CRVO are needed. The results of ongoing RCTs on intravitreal triamcinolone, anti-vascular endothelial growth factor agents, and chorioretinal anastomosis are awaited with interest.

Vitrectomy for non-ischaemic macular oedema in retinal vein occlusion

PURPOSE

To evaluate the effect of vitrectomy in eyes with non-ischaemic macular oedema secondary to hemi and central retinal vein occlusion.

METHODS

This retrospective study analysed the outcome of eight patients with non-ischaemic macular oedema without posterior vitreous detachment. Six patients had a central retinal vein occlusion and two had a hemi retinal vein occlusion. A standard three-port vitrectomy was performed in all patients. Retinal mapping by optical coherence tomography and visual acuity (VA) testing were performed before vitrectomy and at 1, 2 and 12 months postoperatively.

RESULTS

At the 1-month follow-up there was a statistically significant reduction in retinal thickness (Wilcoxon; p = 0.04) that persisted at 2 months (Wilcoxon; p = 0.04). However, at 12 months there was no difference compared with baseline. LogMAR VA was significantly improved at 1 month (Wilcoxon p = 0.04), but at 2 and 12 months there was no difference compared with baseline.

CONCLUSIONS

Vitrectomy in hemi and central retinal vein occlusion has the potential to reduce macular oedema and improve VA in the early postoperative phase but does not seem to improve the longterm outcome of the disease.

Internal limiting membrane peeling for decompression of macular edema in retinal vein occlusion: a report of 14 cases

BACKGROUND

Currently, there is no proven treatment for macular edema due to central retinal vein occlusion (CRVO). Moreover, not all cases with macular edema due to branch retinal vein occlusion (BRVO) respond to laser photocoagulation. We postulated that internal limiting membrane (ILM) peeling for decompression of macular edema in cases of retinal vein occlusion would facilitate egress of blood and extracellular fluid out of the inner retinal layers, leading to reduction of macular edema and improvement in visual acuity.

METHODS

Fourteen consecutive patients with macular edema due to CRVO or selected cases of BRVO, not eligible for laser photocoagulation, underwent pars plana vitrectomy with removal of preretinal hyaloid and peeling of the ILM stained with indocyanine green dye.

RESULTS

In all cases, intraretinal blood and retinal thickening diminished within 6 weeks of surgery. Visual acuity improved in 78.6% of cases. No surgical complications occurred, although one patient developed nuclear cataract 10 months postoperatively.

CONCLUSION

Pars plana vitrectomy with ILM peeling in selected cases of CRVO and BRVO showed improvement in visual acuity in this nonrandomized, noncontrolled study. This pilot study adds support to the concept that ILM peeling may of visual benefit when compared with the natural history in these vaso-occlusive diseases.

Central retinal vein occlusion: review of management

Central retinal vein occlusion is usually a disease of the elderly and is often associated with systemic vascular disease, e.g., hypertension, diabetes mellitus, arteriosclerotic vascular disease. Younger patients, especially those less than 45 years of age, with retinal vein occlusion should be evaluated carefully for the possibility of an underlying thrombotic tendency. The authors describe the ocular manifestations, pathogenesis, associated conditions, patient evaluation, and treatment of patients with central retinal vein occlusion.