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• W2044227887 abstract "Purpose: To evaluate the efficacy of intravitreal bevacizumab in treating recurrent vitreous haemorrhage (VH) after diabetic vitrectomy. Methods: Consecutive patients with postoperative recurrent VH ≥ 2 weeks after primary diabetic vitrectomy were treated with intravitreal bevacizumab. Repeated injection was given after 2–3 weeks in case of no obvious blood reabsorption (study group). Consecutive patients with the same complication but without bevacizumab injection served as the control group. Vitreous surgeries in both groups were indicated if no clinical improvement was noted 10–12 weeks after the initial bleeding. Vitreous clear-up time (VCT), vitreous surgeries and rebleeding rates, and visual acuity changes were compared between both groups. Results: The study group had 20 eyes (20 patients) and the control group had 18 eyes (18 patients). Postoperative VH occurred between 1 and 25 months and between 1 and 18 months, respectively. In the study group, VCT after the first recurrent VH was 6.5 ± 1.5 weeks with 2.2 ± 0.8 injections. Nine cases had ≥ one episode of VH, but no surgery was needed. In the control group, 13 eyes had spontaneous re-absorption (in 6.4 ± 1.3 weeks); five eyes underwent surgeries; three of the 13 eyes eventually had surgeries after further recurrent VH. The rate of vitreous surgery in the two groups was 0/20 and 8/18 (p = 0.01). The total number of rebleeding was 30 in the study group and 27 in the control group (p = 0.69). Conclusion: Intravitreal bevacizumab treatment may reduce the need of revitrectomy for recurrent vitreous haemorrhage after diabetic vitrectomy. Recurrent vitreous haemorrhage after successful diabetic vitrectomy may lead to prolonged and severe visual loss, and sometimes requires surgical intervention (Schachat et al. 1983; Mieler & Wolf 1994). Although adequate retinal ablation plus sclerotomy site cryo has been found to decrease the rate of recurrent vitreous haemorrhage, late-onset vitreous haemorrhage remains a problem for visual rehabilitation (Yeh et al. 2005). The bleeding may come from residual fibrovascular tissues or be related to peripherally located postoperative neovascularization (Kreiger 1993; Koch et al. 1995; Terasaki et al. 1997). Although simple air–fluid exchange or vitreous lavage may help to clear the vitreous opacity, further recurrent haemorrhage is not uncommon (Blumenkranz et al. 1986). Alternatively, vitrectomy with excision of fibrovascular tissue situated in the vitreous base area has been used to eradicate the source of bleeding (Abrams & Williams 1987; Sawa et al. 2000; West & Gregor 2000). However, the procedures are complicated and have potential complications. Intravitreal bevacizumab (Avastin®) has been noted to induce rapid regression of retinal and iris neovascularization (Avery et al. 2006; Isaacs & Barry 2006; Oshima et al. 2006; Minnella et al. 2008). Recently, Jose’ Ma Ruiz-Moreno and associates demonstrated a rapid clearing of recurrent haemorrhage in four cases after diabetic vitrectomy (Ruiz-Moreno et al. 2008). We hypothesize that intravitreal injection of bevacizumab in eyes with late recurrent vitreous haemorrhage may induce regression of new vessels and reduce the possibility of repeated bleeding, thus shortening the reabsorption time and reducing the need for surgery. We conducted a retrospective case–control study to investigate whether or not intravitreal bevacizumab facilitates vitreous clear-up after late-onset recurrent vitreous haemorrhage. From September 2006 to June 2008, consecutive cases with significant recurrent postoperative vitreous haemorrhage after diabetic vitrectomy were treated with intravitreal bevacizumab. All cases in this study group fulfilled the following criteria: recurrent vitreous haemorrhage obscuring the disc and vessels for more than 14 days after initial postoperative complete vitreous clear-up for more than 1 week and no evidence of retinal detachment for a minimum of 8 months of follow-up. From July 2005 to September 2006, consecutive patients fulfilling the same criteria as for the study cases were included as the control group. None of the patients in the control group received intravitreal bevacizumab for treating recurrent haemorrhage. The follow-up time of the control group was limited to a maximum of 2 years to match the study group. A single surgeon (Yang CM) performed all primary vitrectomies and postoperative treatments. The study was approved by the Institutional Research Board of National Taiwan University Hospital. The bevacizumab injection procedures were performed after informed consent was obtained from the patients of the study group. In both groups, a pre operative intravitreal bevacizumab injection was given to patients with ≥ grade 2 (as defined below) active fibrovascular proliferation (defined as visible new vessels within the proliferative membrane with the presence of fresh vitreous haemorrhage) to reduce intraoperative bleeding (Yang et al. 2007). For primary vitrectomy, a standard 3-port 20-gauged pars plana vitrectomy was performed as described previously (Yang et al. 2007). In short, vitreoretinal traction, fibrovascular tissues and opacified vitreous tissue, as well as blood clots adherent to the peripheral vitreous skirt, were removed as completely and safely as possible. Blood clots formed during tissue dissection were removed carefully, except on the bleeding sites where they were trimmed to small islands. Pan-retinal photocoagulation (PRP) in nonlaser-treated eyes or supplementary laser in previously laser-treated eyes, extending beyond the level of the equator was performed. Further, peripheral retinal ablation was executed by transscleral anterior retinal cryotherapy. A range of 10–15% C3F8 was infused intravitreally in cases of retinal breaks or significant fibrovascular proliferation. Finally, cryotherapy of the sclerotomy sites (1 spot, 6 seconds/each, for three sclerotomy sites) was performed (Yeh et al. 2005). After onset of recurrent vitreous haemorrhage, all patients had ultrasonography examination to confirm retinal attachment. Selected cases had ultrasound biomicroscopic examination of the three sclerotomy sites for evidence of fibrovascular ingrowths (Yeh et al. 2005). For each episode of recurrent haemorrhage, the following guideline was used. In the control group, 10–12 weeks of observation following onset of vitreous haemorrhage were allowed for vitreous clear-up. If fundus examination showed no decrease in the severity grade of the vitreous haemorrhage and best-corrected visual acuity showed worsening or no improvement, additional 20-gauged vitreous surgeries including vitreous lavage with fill-in PRP and/or peripheral retinal cryotherapy were performed. Sclerotomy sites cryotherapy (single spot, 4 seconds in duration) was performed in patients with ultrasound evidence of fibrovascular ingrowths. In the study group, with proper disinfection, intravitreal injection of bevacizumab (1.25 mg in 0.05 ml) was given through pars plana 2 weeks after recurrent haemorrhage. Further, supplementary PRP, extending beyond the equator, was performed after vitreous clear-up. Repeated injection was performed 2–3 weeks after the first injection if clinical examinations showed no improvement in best corrected visual acuity and no improvement in vitreous opacity. A total of 8–10 weeks after the first bevacizumab injection were allowed for improvement in the vitreous opacity. Similar criteria were set for surgical intervention. Data regarding systemic conditions of the patients, including the presence of hypertension (systolic pressure over 140 mmHg and/or diastolic pressure over 90 mmHg), cardiac disease, renal disease or bleeding tendency, were recorded. Pre-operative diagnosis and treatment, severity of fibrovascular proliferation, surgical procedures, adjunct treatment, use of gas, use of anticoagulants, date of onset of recurrent vitreous haemorrhage and intravitreal injection, duration for vitreous clear-up after bevacizumab injection, number and duration as well as treatment of further recurrent haemorrhage, were also recorded. The severity of fibrovascular proliferation was graded as follows: grade 1 had focal adhesions only; Ggade 2 had proliferation causing broad adhesion ≥ 1 sites or vitreous-retinal adhesion at disc, macula or arcade; grade 3 had vitreous-retinal attachment extending to the periphery from the fibrovascular proliferation. The severity of each vitreous haemorrhage was evaluated by a grading scheme for vitreous haze ranging from 0 to 5 (0 = none; 1 = minimal, posterior pole clearly visible; 2 = mild, posterior pole details slightly hazy; 3 = moderate, posterior pole details very hazy; 4 = marked, posterior pole details barely visible; 5 = severe, fundal details not visible) (Nussenblatt et al. 1985). The grading of vitreous haemorrhage of all patients (in both the study and the control group) was performed and agreed upon by two retinal specialists in the investigating group (Yang CH and Yang CM). Vitreous clear-up was defined as less than grade 2 of vitreous haemorrhage after blood reabsorption. Snellen best-corrected visual acuity measurements, intraocular pressure, slit-lamp examination and noncontact lens biomicroscopic examination were performed before treatment and during each follow-up visit. Visual acuity was classified into four grades: low or grade1 (logMAR > 1.3), moderate or grade 2 (logMAR ≤ 1.3, but logMAR > 1.0), fair or grade 3 (logMAR ≤ 1.0, but logMAR > 0.5) or good or grade 4 (logMAR ≤ 0.5). Light perception vision was assigned as logMAR vision of 2.0, hand motion vision as logMAR vision of 1.9 and counting finger vision as logMAR vision of 1.8. To examine the differences between study and control groups, statistical analyses of noncontinuous variables were performed with chi-squared test or Fisher’s exact test. If there were zero events in one or both arms in a 2 by 2 table, continuity correction was added. Continuous variables were presented as mean ± standard deviation, and the Mann–Whitney test was performed to make comparisons between study and control groups. All of the statistical analyses were performed using STATA 8.2 software (StataCorp LP, College Station, Texas, USA). A p value <0.05 was considered statistically significant. Twenty cases (20 eyes of 20 patients) were enroled in the study group and 18 cases (18 eyes of 18 patients) were included in the control group. The patients ranged in age from 33 to 70 (average: 53.5 ± 10.6) in the study group and from 29 to 74 (average: 54.1 ± 11.9) in the control group. Most cases (19 and 16, respectively) had noninsulin-dependent diabetic mellitus (NIDDM). Baseline features including systemic diseases, DM type and duration, PDR severity between the study group and the control group did not show a statistically significant difference (Table 1). Pre-operative intravitreal bevacizumab treatment was given to 12 cases in the study group and 10 cases in the control group. Complete vitreo-retinal traction release was achieved in every case. Vitreous haemorrhage occurred between 1 and 25 months after primary vitrectomy in the study group and between 1 and 18 months in the control group. In the study group, the time interval between the vitreous haemorrhage and the intravitreal bevacizumab injection ranged from 2 to 3 weeks (average: 2.3 ± 0.5 weeks); an average of 4.3 ± 1.4 weeks after injection (range: 1–6 weeks), with an average of 2.2 ± 0.8 injections, was required for vitreous clear-up; total reabsorption time after recurrent haemorrhage was 6.5 ± 1.5 weeks (range: 3–9 weeks). Second-episode recurrent vitreous haemorrhage was noted in nine cases, with an average haemorrhage-free period of 4.5 ± 4.0 months. It took an average of 3.0 ± 1.1 weeks and a single injection in four and two injections in the other five to regain vitreous clear-up; one case in the study group had a third episode of recurrent bleeding, which required two more injections. All 20 eyes of the study group had clear vitreous fluid at the end of follow-up. In the control group, spontaneous re-absorption occurred in 13 eyes in an average of 6.4 ± 1.3 weeks; five other eyes underwent further surgeries. Second-episode recurrent vitreous haemorrhage was noted in six of the 13 eyes in the spontaneous re-absorption cases, with an average haemorrhage-free period of 3.8 ± 1.7 months. Three of the 6 eyes eventually received further surgeries. Summary flow charts of clinical course and treatment for the study and the control group were shown in Fig. 1. Overall, no eyes (0/20) in the study group needed further surgical intervention, but 8 eyes (8/18) in the control group received between 1 and 3 (average: 1.1 ± 1.0) surgeries (p = 0.01) (Fig. 2). The total number of rebleeding was 30 in the study group and 27 in the control group (p = 0.69). Clinical characteristics and time course of recurrent vitreous haemorrhage in the study and the control group are shown in Table 2. UBM was performed in 14 cases in the study group and 12 cases in the control group. One and three cases had evidence of entry-site NV in the two groups, respectively. Because of the small case number, statistical analyses to determine the influence of entry-site NV on treatment effect were not performed. Visual acuity improved in all 20 eyes in the study group after clearing of vitreous haemorrhage and in 18 eyes in the control group after spontaneous vitreous clear-up or after surgeries. The pre-operative visual grade was grade 1 in all cases in both groups, and post operative visual grade was 2.75 ± 0.79 in the study group and 2.39 ± 0.98 in the control group (p = 0.15) (Table 3 and Fig. 2). Flow charts of clinical course and treatment for all the cases in the study group (treated with intravitreal Avastin injections) and the control group. All patients had clear vitreous at the end of follow-up in this study. IVI: intraviteal injection; RVH: recurrent vitreous haemorrhage, VH: vitreous haemorrhage. Histograms showed comparison of frequency of surgical intervention as well as pre- and postoperative logMAR VA (visual acuity) between the study and the control group. *p < 0.05. In the study group, there were no injection-related local or systemic complications. One case with previous filtering surgery for neovascular glaucoma in the study group developed high intraocular pressure and rubeosis, 5 weeks after surgery. To treat recurrent haemorrhage and high intraocular pressure, we conducted trans-scleral cyclophotocoagulation and intravitreal injection of bevacizumab at the same setting. Intraocular pressure then returned to normal with antiglaucoma eye drops. In the control group, one patient developed a neovascular glaucoma combined with rebleeding 16 weeks after primary vitrectomy. Three additional vitrectomies combined with anterior retinal cryotherapy, lens extraction and silicone oil infusion were performed. Eventually, the intraocular pressure was under control and the corrected visual acuity remained 20/200. Many methods have been used to treat postvitrectomy persistent or recurrent haemorrhage, including gas–fluid exchange, pan-retinal cryotherapy, vitreous lavage and dissection of entry-site fibrovascular proliferation (Blumenkranz et al. 1986; Neely et al. 1998; Steel et al. 2008). For intractable cases, silicone oil has been infused after vitreous lavage to obtain long term clear media (Bodanowitz et al. 1997). Most treatment options involve intraocular procedures and may have severe potential complications (Lewis 1994). The results of our study show that compared with the control, repeated intravitreal bevacizumab injection may facilitate reabsorption of vitreous blood and thus may reduce additional vitreous surgeries. The source of recurrent haemorrhage may vary (Kreiger 1993; Koch et al. 1995; Terasaki et al. 1997). In the early postoperative period, bleeding from injured vessels or residual fibrovascular tissue, or early regrowth of neovascularization may be the causes (Yang et al. 2007); late recurrent haemorrhage is more likely associated with neovascularization from the peripheral retina or instrument entry sites (Steel et al. 2008). In this study, although careful fundus biomicroscopic examination during follow-up failed to detect neovascularization formation and vitreo-retinal traction in any of our cases, the onset time of recurrent haemorrhage, the good response of this complication to bevacizumab treatment and the ultrasound biomicroscopic evidence of entry-site neovascularization in some cases suggest that new vessels developing in the vitreous base or sclerotomy entry sites remains the most possible source of recurrent bleeding. As in diabetic vitreous haemorrhage without surgery, there may be bleeding in more than one occasion during the process of blood reabsorption (Ramsay et al. 1977). With intravitreal bevacizumab, the neovascularization regresses; repeated inflow of blood into the vitreous may thus be stopped. In our study, some cases had only one episode of bleeding during follow-up; others developed further recurrent bleeding. Repeated recurrent vitreous haemorrhage suggests the presence of protracted NV or sustained release of angiogenic factors. Because bevacizumab has only temporal effects, the possibility of recurrent vitreous haemorrhage raises the question of whether bevacizumab should be used at regular intervals as a preventive method (Bakri et al. 2007; Heiduschka et al. 2007). In our study, prolonged clear vitreous could be obtained after blood reabsorption in most cases, and when recurrent bleeding occurred, further bevacizumab treatment remained effective. The haemorrhage-free period among patients in our study was 5.9 months on average. For these reasons, we believe that prophylactic injection on a nonselected base may not be necessary. However, if certain risk factors arise during follow-up, such as intraocular surgery, intraocular inflammation, haemodialysis or anticoagulant use, one or two booster injections of bevacizumab may be a reasonable option. On the other hand, there is no evidence demonstrating that multiple injections induce permanent neovascularization regression in severe cases; therefore, supplementary retinal ablation, especially to the anterior retina, should be performed as an adjunct treatment to decrease the opportunity of reactivation and bleeding of neovascularization. Bevacizumab may have a considerably shorter half life in the vitreous cavity in a vitrectomized eye than a nonvitrectomized eye. As pharmacokinetic data of bevacizumab in vitrectomized eyes remain lacking, we extrapolated results from intravitreal antibiotics studies, which showed that the vitreous clearance rate in vitrectomized eyes was in general 2 or 3 times faster compared with nonvitrectomized eyes (Ficker et al. 1990). We thus chose 3 weeks as the interval between two bevacizumab injections when prolonged haemorrhage developed. The optimal interval for repeated injection requires further studies. Some of our cases had ultrasound biomicroscopic evidence of entry-site neovascularization. Steel DH et al. suggested that entry-site neovascularization was correlated with the need for vitreous lavage (Steel et al. 2008). West and Gregor suggested ciliary membrane dissection, laser or cryotherapy over sclerotomy sites to stop recurrent haemorrhage from pre-existing entry-site neovascularization (West & Gregor 2000). The available data in our study did not show that such cases had a more protracted course after bevacizumab injection. A larger number of cases may be needed to know if cases with entry-site neovascularization may need more frequent bevacizumab injections or are prone to have more episodes of recurrent bleeding. The potential complications of bevacizumab treatment include injection related endophthalmitis and retinal breaks. It has been suggested that the vascular endothelium growth factor (VEGF) may play an important role in maintaining the normal function of platelets (Mosesson 2005). The use of anti-VEGF might possibly disrupt blood clot aggregation and cause a rapid release of degenerated red blood cells within the vitreous cavity or into the anterior chamber in a vitrectomized eye, thus potentially inducing elevation of the intraocular pressure (Yang et al. 2008). The generally unsatisfactory final visual acuity in both groups might be because of the nature of the disease. The statistical analysis of visual acuity did not show any significant difference between both groups. While our study suggests that repeated intravitreal bevacizumab injection may be effective in facilitating reabsorption of vitreous blood and may reduce additional vitreous surgeries, it has certain limitations. First, the study was retrospective in nature and there were many confounding factors; although the baseline characteristics of the two groups were matched, study bias was inevitable. Second, both groups had only a small number of cases with NIDDM in most and there was no complete data regarding the presence of sclerotomy site neovascularization, making subgroup analysis difficult. Further study with prospective design and a larger case number may be necessary to confirm the efficacy of the treatment and to address the questions regarding the optimal treatment interval and the necessity of preventive injection." @default.
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• W2044227887 title "Intravitreal bevacizumab injection for recurrent vitreous haemorrhage after diabetic vitrectomy" @default.
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