Bevacizumab pretreatment and long-acting gas infusion on vitreous clear-up after diabetic vitrectomy

[Medico-surgical management of intravitreal hemorrhage in diabetic patients]

Vitreous hemorrhage (VH) is the main complication of proliferative diabetic retinopathy and remains the primary indication for vitrectomy in diabetic patients. The objective of our study is to compare our medical and surgical management of VH with data from the literature and to report the functional results of our series. We studied a series of 284 cases collected over 2 years in two tertiary care centers. In our series, 90.1% of patients had type 2 diabetes, and 70% had glycosylated hemoglobin greater than 7.5%. On fundus examination, 35.2% presented with stage 1 VH, 42.6% with stage 2, 3.6% with stage 3 and 5.2% with stage 4. Ocular ultrasound performed when fundus exam was difficult diagnosed an associated tractional retinal detachment in 8.8% of patients. Medical treatment was sufficient in 77.8% of patients, while 22.2% of our patients underwent vitrectomy, argon laser endophotocoagulation and postoperative anti-VEGF injection. Peeling of tractional fibrovascular membranes and or associated epiretinal membranes was performed in 69.8% of cases. Iatrogenic tears were noted in 11.8% of patients. In this study, 31.5% of patients underwent intraocular gas tamponade, while 23.8% of cases underwent silicone oil tamponade. Postoperative visual acuity improved by at least 2 lines in 60% of our patients, and the VH recurred in 24.2% of cases after surgery.

Anti-vascular endothelial growth factors in combination with vitrectomy for complications of proliferative diabetic retinopathy

BACKGROUND

Vitrectomy is an established treatment for the complications of proliferative diabetic retinopathy (PDR). However, a number of complications can occur during and after vitrectomy for PDR. These include bleeding and the creation of retinal holes during surgery, and bleeding, retinal detachment and scar tissue on the retina after surgery. These complications can limit vision, require further surgery and delay recovery. The use of anti-vascular endothelial growth factor (anti-VEGF) agents injected into the eye before surgery has been proposed to reduce the occurrence of these complications. Anti-VEGF agents can reduce the amount and vascularity of abnormal new vessels associated with PDR, facilitating their dissection during surgery, reducing intra- and postoperative bleeding, and potentially improving outcomes.

OBJECTIVES

To assess the effects of perioperative anti-VEGF use on the outcomes of vitrectomy for the treatment of complications for proliferative diabetic retinopathy (PDR).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2022, Issue 6); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 22 June 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that looked at the use of anti-VEGFs and the incidence of complications in people undergoing vitrectomy for PDR.   DATA COLLECTION AND ANALYSIS: Two review authors independently assessed and extracted the data. We used the standard methodological procedures expected by Cochrane. The critical outcomes of the review were the mean difference in best corrected visual acuity (BCVA) between study arms at six (± three) months after the primary vitrectomy, the incidence of early postoperative vitreous cavity haemorrhage (POVCH, within four weeks postoperatively), the incidence of late POVCH (occurring more than four weeks postoperatively), the incidence of revision surgery for POVCH within six months, the incidence of revision surgery for recurrent traction/macular pucker of any type and/or rhegmatogenous retinal detachment within six months and vision-related quality of life (VRQOL) measures. Important outcomes included the proportion of people with a visual acuity of counting fingers (1.8 logMAR or worse), the number of operative retinal breaks reported and the frequency of silicone oil tamponade required at time of surgery.

MAIN RESULTS

The current review includes 28 RCTs that looked at the pre- or intraoperative use of intravitreal anti-VEGFs to improve the outcomes of pars plana vitrectomy for complications of PDR. The studies were conducted in a variety of countries (11 from China, three from Iran, two from Italy, two from Mexico and the remaining studies from South Korea, the UK, Egypt, Brazil, Japan, Canada, the USA, Indonesia and Pakistan). The inclusion criteria for entry into the studies were the well-recognised complications of proliferative retinopathy: non-clearing vitreous haemorrhage, tractional retinal detachment involving the macula or combined tractional rhegmatogenous detachment. The included studies randomised a total of 1914 eyes.  We identified methodological issues in all of the included studies. Risk of bias was highest for masking of participants and investigators, and a number of studies were unclear when describing randomisation methods and sequence allocation. Participants receiving intravitreal anti-VEGF in addition to pars plana vitrectomy achieved better BCVA at six months compared to people undergoing vitrectomy alone (mean difference (MD) -0.25 logMAR, 95% confidence interval (CI) -0.39 to -0.11; 13 studies, 699 eyes; low-certainty evidence). Pre- or intraoperative anti-VEGF reduced the incidence of early POVCH (12% versus 31%, risk ratio (RR) 0.44, 95% CI 0.34 to 0.58; 14 studies, 1038 eyes; moderate-certainty evidence). Perioperative anti-VEGF use was also associated with a reduction in the incidence of late POVCH (10% versus 23%, RR 0.47, 95% CI 0.30 to 0.74; 11 studies, 579 eyes; high-certainty evidence). The need for revision surgery for POVCH occurred less frequently in the anti-VEGF group compared with control, but the confidence intervals were wide and compatible with no effect (4% versus 13%, RR 0.44, 95% CI 0.15 to 1.28; 4 studies 207 eyes; moderate-certainty evidence). Similar imprecisely measured effects were seen for revision surgery for rhegmatogenous retinal detachment (5% versus 11%, RR 0.50, 95% CI 0.15 to 1.66; 4 studies, 145 eyes; low-certainty evidence).  Anti-VEGFs reduce the incidence of intraoperative retinal breaks (12% versus 31%, RR 0.37, 95% CI 0.24 to 0.59; 12 studies, 915 eyes; high-certainty evidence) and the need for silicone oil (19% versus 41%, RR 0.46, 95% CI 0.27 to 0.80; 10 studies, 591 eyes; very low-certainty evidence). No data were available on quality of life outcomes or the proportion of participants with visual acuity of counting fingers or worse.

AUTHORS' CONCLUSIONS

The perioperative use of anti-VEGF reduces the risk of late POVCH, probably results in lower early POVCH risk and may improve visual outcomes. It also reduces the incidence of intraoperative retinal breaks. The evidence is very uncertain about its effect on the need for silicone oil tamponade. The reported complications from its use appear to be low. Agreement on variables included and outcome standardisation is required in trials studying vitrectomy for PDR.

Review of Studies Comparing Panretinal Photocoagulation and Anti-Vascular Endothelial Growth Factor Therapy in the Treatment of Proliferative Diabetic Retinopathy

Diabetic retinopathy (DR) is among the leading causes of blindness at the global level. A review of studies between 2015 and 2018 found that about 1.7% of the general population with any type of diabetes mellitus suffered from proliferative diabetic retinopathy (PDR). Since the 1960s, panretinal photocoagulation (PRP) has been the mainstay of treatment for PDR. During this period, PRP has been credited with a significant degree of success and a relatively low complication rate. However, the advent of anti-vascular endothelial growth factor (anti-VEGF) therapy with the beginning of the new millennium provided a treatment modality that was noninferior to PRP. A decade-long period of comparisons and debates between these two treatment modalities repeatedly favored anti-VEGF over PRP, as studies demonstrated that the former provided potentially superior outcomes to PRP. The aim of this review is to briefly discuss and compare the relevant studies and evidence supporting these two treatments.

Intravitreal bevacizumab prior to vitrectomy for proliferative diabetic retinopathy: a systematic review

Background:

Diabetic retinopathy is a leading cause of visual loss in the working population. Pars plana vitrectomy has become the mainstream treatment option for severe proliferative diabetic retinopathy (PDR) associated with significant vitreous haemorrhage and/or tractional retinal detachment. Despite the advances in surgical equipment, diabetic vitrectomy remains a challenging operation, requiring advanced microsurgical skills, especially in the presence of tractional retinal detachment. Preoperative intravitreal bevacizumab has been widely employed as an adjuvant to ease surgical difficulty and improve postoperative prognosis.Aims: This study aims to assess the effectiveness of preoperative intravitreal bevacizumab in reducing intraoperative complications and improving postoperative outcomes in patients undergoing vitrectomy for the complications of PDR.

Methods:

A literature search was conducted using the PubMed, Cochrane, and ClinicalTrials.gov databases to identify all related studies published before 31/10/2020. Prespecified outcome measures were operation time, intraoperative iatrogenic retinal breaks, best-corrected visual acuity in the last follow-up visit, the presence of any postoperative vitreous haemorrhage and the need to re-operate. Evidence synthesis was performed using Fixed or Random Effects models, depending on the heterogeneity of the included studies. Heterogeneity was assessed using Q-statistic and I². Additional meta-regression models, subgroup analyses and sensitivity analyses were performed as appropriate.

Results:

Thirteen randomized control trials, with a total of 688 eyes were included in this review. Comparison of the intraoperative data showed that bevacizumab reduced operation time (p < 0.001), minimized iatrogenic retinal breaks (p < 0.001), provided better long-term visual acuity outcomes (p = 0.005), and prevented vitreous haemorrhage (p < 0.001) and the need for reoperation (p = 0.001 < 0.05). Findings were strongly corroborated by additional sensitivity and subgroup analyses.

Conclusion:

Preoperative administration of bevacizumab is effective in reducing intraoperative complications and improving the postoperative prognosis of diabetic vitrectomy.

PROSPERO registration number: CRD42021219280

Is Chronic Kidney Disease Affecting the Postoperative Complications of Vitrectomy for Proliferative Diabetic Retinopathy?

Chronic kidney disease (CKD) is a well-known risk factor for postoperative complications in several surgical fields. However, although prevalent among diabetic candidates for vitrectomy, the effect of CKD on vitrectomy outcomes remains unclear. This study aimed at clarifying the relationship between CKD and the occurrence of vitrectomy-related complications in patients with proliferative diabetic retinopathy (PDR). The 6-month incidences of vitreous hemorrhage (VH) and neovascular glaucoma (NVG) following vitrectomy for PDR were compared among the following groups: stages 1–2 CKD (60 patients), stages 3–5 CKD (70 patients not on hemodialysis), and hemodialysis (HD; 30 patients). We also determined whether the deterioration of the estimated glomerular filtration rate (eGFR) was associated with post-vitrectomy events. The incidence of VH was significantly higher in the stages 3–5 CKD group (43%) than in the stages 1–2 CKD (10%) and HD (10%) groups. NVG was more common in the stages 3–5 CKD group (17%) than in the stages 1–2 CKD (2%) and HD (0%) groups. The reduced estimated glomerular filtration rate (eGFR) was the only significant variable associated with post-vitrectomy VH and NVG. Patients with PDR and CKD, particularly those with lower eGFR, might be at risk for post-vitrectomy VH and NVG.

Effect of intravitreal conbercept injection on VEGF-A and -B levels in the aqueous and vitreous humor of patients with proliferative diabetic retinopathy

The present study aimed to investigate the mechanisms of anti-VEGF treatment prior to eye surgery to reduce intraoperative bleeding. A total of 30 patients with proliferative vitreoretinopathy after clinical diagnosis were enrolled in the present study as the surgical group. Furthermore, 30 patients underwent intravitreal injection of the anti-VEGF drug conbercept and were considered the drug pretreatment group. The aqueous and vitreous humors from the eyes of patients in the surgical group were drawn during pars plana vitrectomy surgery. The aqueous humor in the eyes of patients in the drug pretreatment group was drawn prior to conbercept treatment and seven days after conbercept treatment immediately prior to surgery. The vitreous humor in this group was only taken during surgery. Furthermore, ELISA was used to detect the levels of VEGF-A and -B in the aqueous and vitreous humors. Semi-quantitative determination of VEGF-A and VEGF-B levels in fibrovascular proliferative membranes was performed using immunohistochemical staining. The results indicated that in the drug group, the levels of VEGF-A in the aqueous humor of patients prior to and after conbercept injection were 197.66±48.00 and 3.39±2.54 pg/ml, respectively. The levels of VEGF-A in the vitreous humor of patients in the surgical and drug groups were 267.53±179.60 and 21.43±5.81 pg/ml after injection, respectively. The levels of VEGF-B in the aqueous humor of patients prior to and after conbercept injection were 13.66±3.30 (before injection) and 2.17±0.94 pg/ml (after injection), respectively. The levels of VEGF-B in the vitreous humor of patients in the surgical and drug groups were 127.36±16.72 and 18.56±9.82 pg/ml after injection, respectively (P<0.05). Furthermore, in the drug group, the surgery time, bleeding and capillary formation were significantly reduced compared with those in the surgical group. Taken together, these results suggested that the levels of VEGF-A and -B decreased significantly in the aqueous humor of patients with PDR after conbercept injection. Furthermore, the levels of VEGF-A and -B in the vitreous humor of patients dropped significantly in the drug group compared with those in the surgical group. These results provide theoretical clinical support for the preoperative application of conbercept for patients with PDR.

Evaluation of vitrectomy combined preoperative intravitreal ranibizumab and postoperative intravitreal triamcinolone acetonide for proliferative diabetic retinopathy

BACKGROUND

To explore the treatment efficacy of the combination of preoperative intravitreal ranibizumab (IVR) and postoperative intravitreal triamcinolone acetonide (IVTA) in patients undergoing pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR).

METHODS

A retrospective comparative study was performed on 128 eyes of 128 patients who had PDR and underwent PPV. Patients who received a single PPV were assigned to Group A. Those who received PPV with preoperative IVR were assigned to Group B. Patients in Group C underwent PPV combined preoperative IVR and postoperative IVTA. Intraoperative findings, changes in mean best-corrected visual acuity (BCVA) and postoperative adverse events, were retrospectively evaluated at 6-month follow-up.

RESULTS

The incidences of iatrogenic breaks, severe intraoperative bleeding, using long-term internal tamponade agents, recurrent vitreous hemorrhage (VH), and duration of surgery were statistically significantly less in Group B and Group C than in Group A. The postoperative BCVA was statistically significantly better in Groups B and Group C than in Group A, respectively, at 1 month after surgery. The mean 3-month postoperative visual acuity was better in Group C. The incidence of high intraocular pressure (IOP) was significantly higher in Group C at the first postoperative week. There were no statistically significant differences in the incidence of exudative retinal detachment and choroidal detachment among the three groups.

CONCLUSION

In patients undergoing PPV for PDR, preoperative IVR significantly reduced the occurrence of intraoperative and postoperative complications, and the combination of preoperative IVR and postoperative IVTA can better improve the postoperative visual outcome.

Multiple factors in the prediction of risk of recurrent vitreous haemorrhage after sutureless vitrectomy for non-clearing vitreous haemorrhage in patients with diabetic retinopathy

Background

We aimed to analyse multiple factors in the prediction of risk of postoperative recurrent vitreous haemorrhage (RVH) for non-clearing vitreous haemorrhage in patients with diabetic retinopathy (DR) who underwent sutureless vitrectomy with 23- (23G) or 25-gauge (25G) narrow-gauge systems.

Methods

A retrospective consecutive case series design was used. DR patients who underwent sutureless vitrectomy for non-clearing vitreous haemorrhage between June 2017 and October 2019 were enrolled. All operations were performed at a tertiary hospital. Patient demographics and risk factors, including age, gender, duration of diabetes, preoperative fasting blood sugar levels (FBSL), systolic blood pressure (SBP), serum creatinine (Cr), urea, triamcinolone acetonide (TA), electrical coagulation, air-fluid exchange, pan-retinal photocoagulation status (PRP), anti-vascular endothelial growth factor drug (anti-VEGF), and other factors, were recorded. Patients were divided into two groups based on the timing of their postoperative RVH: immediate postoperative RVH (within 2 weeks after operation) and delayed postoperative RVH (beyond 2 weeks after operation).

Results

Overall, 167 eyes (167patients) were enrolled. Seventy eyes were underwent 23G and 25G sutureless vitrectomy performed in 97 eyes, respectively. Postoperative RVH developed in 18 eyes (25.7%) in Group 23G and in 20 eyes (21.6%) in Group 25G (P = 0.540). Of these, 3 eyes (4.3%) had severed RVH in Group 23G compared with 5 eyes (5.2%) in Group 25G (P = 0.584). Delayed postoperative RVH occurred in 6 eyes (8.6%) in Group 23G and 8 eyes (8.2%) in Group 25G (P = 0.789). A binomial logistic regression analysis revealed that age, duration of diabetes, and Cr level were significantly associated with RVH in both Group 23G (P < 0.05) and Group 25G (P < 0.05).

Conclusions

The incidence and severity of RVH were 25.7 and 4.3%, respectively, in Group 23G and 21.6 and 5.2%, respectively, in Group 25G. Thus, the 23G sutureless vitrectomy approach was as safe as the 25G sutureless vitrectomy approach for treating vitreous haemorrhage in patients with DR. A younger age, shorter duration of diabetes, and higher Cr levels were risk factors for postoperative RVH in sutureless vitrectomy.

Intravitreal Conbercept Injection as an Adjuvant in Vitrectomy with Silicone Oil Infusion for Severe Proliferative Diabetic Retinopathy

Purpose: To assess the clinical effects of preoperative, intraoperative, or preoperative combined with intraoperative intravitreal conbercept (IVC) injection in vitrectomy with silicone oil tamponade for severe proliferative diabetic retinopathy (PDR). Methods: Ninety-eight eyes of 98 severe PDR patients undergoing vitrectomy with silicone oil tamponade were randomly assigned to 3 groups: Group 1 (34 eyes) received IVC injections 3 to 5 days before surgery; Group 2 (35 eyes) received IVC injections at the end of surgery; and Group 3 (29 eyes) received IVC injections 3 to 5 days before and at the end of operation. Follow-up examinations were performed for 6 months. Results: The incidence and severity of intraoperative bleeding were not significantly different (P = 0.233). However, the duration of surgery was significantly shorter in Group 1 and Group 3 compared with Group 2 (P < 0.001). The incidences of early and late recurrent vitreous hemorrhage (VH) were 32.35%, 28.57%, and 13.80%, respectively. At 6-month follow-up, mean best-corrected visual acuity had significantly increased to 1.25 ± 0.45 logMAR in Group 1, 1.29 ± 0.46 logMAR in Group 2, 1.16 ± 0.44 logMAR in Group 3 (all P < 0.001). The incidence of postoperative VH, neovascular glaucoma, and retinal detachment in Group 3 was slightly lower, however, no significant differences were observed (all P > 0.05). In young patients, similar results were observed and Group 3 had better visual improvements (P = 0.037). Conclusions: Preoperative IVC injection could be a safe and effective adjunct in pars plana vitrectomy with silicone oil tamponade for severe PDR. Preoperative combined with intraoperative IVC are promising, especially in young patients.

Internal Limiting Membrane Flaps for Coexistent Macular Hole and Retinal Detachment in Eyes with Proliferative Diabetic Retinopathy

Purpose

To evaluate logical surgical approaches to closing macular holes in eyes with proliferative diabetic retinopathy with retinal detachment.

Methods

Retrospective, interventional case series.

Results

10 eyes in 10 patients were included in this study. The inverted internal limiting membrane (ILM) flap technique was used in 2 eyes, while inverted ILM insertion was used in 5 eyes, and free ILM flaps in 3 eyes. Closed macular holes and retinal reattachment were observed in all eyes. Best corrected visual acuity improved from 1.33 ± 0.39 preoperatively to 1.02 ± 0.36 postoperatively (p=0.03).

Conclusion

Various surgical approaches utilized in managing macular holes may effectively close macular holes and reattach retinas. This trial is registered with NCT 03618498.

Pars plana vitrectomy in vitreous hemorrhage with or without Intravitreal Bevacizumab a comparative overview

Objective:

To compare the success in patients having vitreous hemorrhage undergoing pars plana vitrectomy with or without preoperative intravitreal injection of Bevacizumab.

Methods:

This Randomized controlled trial was conducted at Department of Ophthalmology, Jinnah Postgraduate Medical Centre. Karachi. Duration of study was six months from January 2010 to June 2010. In this study 56 patients of advanced diabetic eye disease were divided into two groups. Patients in Group-A underwent three ports pars plana vitrectomy with preoperative intravitreal injection of Bevacizumab (Avastin) 1.25mg/0.05ml, 3.5mm from the limbus seven days before surgery and in Group-B patients underwent vitrectomy without preoperative intravitreal Bevacizumab (Avastin). Intraoperative bleeding was monitored in both groups and was graded as no bleeding, mild bleeding and severe bleeding. The results were statistically analyzed through computer software SPSS 17.

Results:

Twenty eight patients in Group-A who were given an injection of intravitreal Bevacizumab (Avastin) before surgery, intraoperative bleeding monitored was, no bleeding in 17 cases (60.7%), mild was observed in 6 cases (21.4%) and severe bleeding requiring diathermy to stop was observed in only 5 cases (17.9%). 28 patients in Group-B that underwent surgery without Avastin no bleeding was observed in only 2 cases (7.1%), mild in 6 cases (21.4%) and severe in 20 cases (71.4%).

Conclusions:

Intravitreal injection of Bevacizumab (Avastin) was effective before vitrectomy in the surgical management of Advanced Diabetic Eye disease.

Segmentation and removal of fibrovascular membranes with high-speed 23 G transconjunctival sutureless vitrectomy, in severe proliferative diabetic retinopathy

Aim

To evaluate the effectiveness and safety of high-speed (5,000 cuts per minute) 23 G transconjunctival sutureless vitrectomy (TSV) in severe diabetic fibrovascular proliferation (DFVP).

Patients and methods

In this retrospective consecutive case series, patients who underwent 23 G TSV for severe DFVP between October 2011 and March 2014 at our institution were evaluated. 23 G TSV was performed with a high-speed (5,000 cuts per minute) cutter without a chandelier light.

Results

The mean follow-up period was 8 months (range: 4–23 months). Of the 27 eyes of 27 patients, 14 eyes (52%) underwent concomitant phacoemulsification with posterior chamber intraocular lens implantation, nine eyes (33%) were pseudophakic, and four eyes were phakic (15%). DFVP was removed with ease in all, and visual acuity was improved in 18 (67%) eyes. Iatrogenic retinal tear was observed in four eyes (15%) and treated successfully during surgery. Suture placement to a single sclerotomy was performed in eight eyes (30%). Postoperative intraocular hemorrhage was observed in five eyes (18%). Cataract formation was observed in two of the four phakic eyes. Three (11%) patients had postoperative intraocular pressure rise. Postoperative hypotony (≤6 mmHg) and endophthalmitis were not observed in any eye.

Conclusion

The segmentation and removal of fibrovascular membranes with high-speed 23 G TSV seems to be a safe and easy method in severe diabetic eye disease.

Surgical treatment for diabetic vitreoretinal diseases: a review

Over the past four decades, advancements in surgical instrumentations and techniques have significantly improved the postoperative anatomical and visual outcomes of patients with various diabetic vitreoretinal diseases. In particular, surgical interventions for previously serious and untreatable blinding proliferative diabetic retinopathy can now be performed, with much better results. The advents of micro incisional vitrectomy system with better visualization system like binocular indirect ophthalmomicroscope and state-of-the-art instrumentation revolutionized the era of diabetic vitrectomy. High-speed vitrectors, finer instruments, chromo-assisted vitrectomy and use of anti-vascular endothelial growth factors not only change the paradigm but also help achieve much better outcome after diabetic vitrectomies. In this review, we will discuss and summarize the indications, surgical considerations, surgical techniques, potential complications and outcomes of vitreoretinal surgery for diabetic eye diseases.

A Randomized Controlled Trial of Conbercept Pretreatment before Vitrectomy in Proliferative Diabetic Retinopathy

Purpose. To determine the efficacy and safety of preoperative intravitreal conbercept (IVC) injection before vitrectomy for proliferative diabetic retinopathy (PDR). Methods. 107 eyes of 88 patients that underwent pars plana vitrectomy (PPV) for active PDR were enrolled. All patients were assigned randomly to either preoperative IVC group or control group. Follow-up examinations were performed for three months after surgery. The primary bioactivity measures were severity of intraoperative bleeding, incidence of early and late recurrent VH, vitreous clear-up time, and best-corrected visual acuity (BCVA) levels. The secondary safety measures included intraocular pressure, endophthalmitis, rubeosis, tractional retinal detachment, and systemic adverse events. Results. The incidence and severity of intraoperative bleeding were significantly lower in IVC group than in the control group. The average vitreous clear-up time of early recurrent VH was significantly shorter in IVC group compared with that in control group. There was no significant difference in vitreous clear-up time of late recurrent VH between the two groups. Patients that received pretreatment of conbercept had much better BCVA at 3 days, 1 week, and 1 month after surgery than control group. Moreover, both patients with improved BCVA were greater in IVC group than in control group at each follow-up. Conclusions. Conbercept pretreatment could be an effective adjunct to vitrectomy in accelerating postoperative vitreous clear-up and acquiring stable visual acuity restoration for PDR.

Anti-vascular endothelial growth factor for prevention of postoperative vitreous cavity haemorrhage after vitrectomy for proliferative diabetic retinopathy

BACKGROUND

Postoperative vitreous cavity haemorrhage (POVCH) is a significant complication following vitrectomy for proliferative diabetic retinopathy (PDR). It delays visual recovery and can make further treatment difficult if the view of the fundus is significantly obscured. A number of interventions to reduce the incidence of POVCH have been proposed, including the perioperative use of anti-vascular endothelial growth factor (anti-VEGF). Anti-VEGFs reduce vascular proliferation and the vascularity of neovascular tissue, which is often the source of bleeding following vitrectomy.

OBJECTIVES

This updated review aimed to summarise the effects of anti-VEGF use to reduce the occurrence of POVCH after vitrectomy surgery for PDR.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015, Issue 4), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to May 2015), PubMed (January 1966 to May 2015), EMBASE (January 1980 to May 2015), Latin American and Caribbean Health Sciences (LILACS) (January 1982 to May 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 26 May 2015.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs that looked at the use of anti-VEGFs and the incidence of POVCH in people undergoing vitrectomy for PDR.

DATA COLLECTION AND ANALYSIS

Both review authors independently assessed and extracted the data. We used standard methodological procedures expected by Cochrane.The primary outcomes of the review were the incidence of early and late POVCH following perioperative anti-VEGF administration. Secondary outcomes included best-corrected visual acuity at six months following surgery, the incidence of vitreous cavity washout or revision vitrectomy at six months, adverse effects of intervention (cataract, iris rubeosis and rubeotic glaucoma, retinal detachment, increased inflammation and systemic side effects), quality of life measures performed at least six months following vitrectomy, and density of POVCH.

MAIN RESULTS

The current review included 12 RCTs that looked at the pre- or intraoperative use of intravitreal bevacizumab to prevent postoperative vitreous haemorrhage during pars plana vitrectomy for complications of PDR. The studies were conducted in a variety of countries (three from Iran, two from Italy, two from Egypt, and the remaining from South Korea, USA, Mexico, Pakistan, and Japan). The inclusion criteria for entry into the studies were standard complications of proliferative retinopathy: non-clearing vitreous haemorrhage, tractional retinal detachment involving the macula, or combined tractional rhegmatogenous detachment. The included studies randomised a total of 654 eyes. The average age of the participants was 54 years.We identified methodological issues in all included studies. Risk of bias was highest for masking of participants and investigators (four studies were an 'open label' design), and a number of studies were unclear when describing randomisation methods and sequence allocation.Participants receiving intravitreal bevacizumab in addition to pars plana vitrectomy were less likely to experience early POVCH (grade 2) compared to people undergoing pars plana vitrectomy alone (risk ratio (RR) 0.28, 95% confidence interval (CI) 0.08 to 0.96, 2 studies, 144 eyes, high-quality evidence). This corresponds to an absolute effect of 130 fewer people (95% CI 167 fewer to 7 fewer) with early POVCH per 1000 people when treated with intravitreal bevacizumab. We saw similar results for all grades of POVCH (RR 0.35, 95% CI 0.23 to 0.53, 9 studies, 512 eyes) and when excluding cases where assessment of outcome was impossible due to presence of silicone oil (RR 0.34, 95% CI 0.19 to 0.60, 6 studies, 302 eyes).The effect of pre- or intraoperative intravitreal bevacizumab on the incidence of late postoperative haemorrhage was uncertain (RR 0.72, 95% CI 0.30 to 1.72, 3 studies, 196 eyes, low-quality evidence). The absolute effect was 55 fewer people (95% CI 138 fewer to 143 more) with late POVCH per 1000 people when treated with intravitreal bevacizumab. This outcome was rarer and was only reported in a few studies. We are currently unable to provide an estimate of the effect of intravitreal bevacizumab on postoperative visual acuity due to significant study heterogeneity.No local or systemic complications of intravitreal bevacizumab were reported by the RCTs. The risk of postoperative retinal detachment was lower in the participants treated with pre- or intraoperative bevacizumab (RR 0.46, 95% CI 0.19 to 1.08, 7 studies, 372 participants, low-quality evidence); the absolute effect was 49 fewer people (95% CI:73 fewer to 8 more) with postoperative retinal detachment per 1000 people when treated with intravitreal bevacizumab.

AUTHORS' CONCLUSIONS

The use of pre- or intraoperative bevacizumab lowers the incidence of early POVCH. The reported complications from its use appear to be low. Futher randomised studies that look at other anti-VEGF medications are ongoing and will strengthen the current review findings, giving both surgeons and patients evidence to guide treatment choices in the management of proliferative retinopathy.

Surgical outcomes of florid diabetic retinopathy treated with antivascular endothelial growth factor

PURPOSE

To evaluate the effectiveness of vitreoretinal surgery combined with antivascular endothelial growth factor therapy to treat florid diabetic retinopathy, a rare and severe form of diabetic retinopathy in young patients.

METHODS

Retrospective observational case series including 61 eyes of 45 patients operated on for florid diabetic retinopathy over the past 5 years, with preoperative or intraoperative intravitreal injection of bevacizumab. Cases were classified into three stages of disease severity, according to the extension of the fibrovascular membranes. Main outcome measures were mean change in visual acuity, anatomical outcome, and surgical complications.

RESULTS

After a mean follow-up of 20.3 months, the mean visual acuity significantly increased from +1.7 logMAR before surgery to +0.8 logMAR after surgery (P < 0.01). The visual gain was significant in Stages I and II (P < 0.05) but not significant in Stage III. A flat retina without silicone oil was achieved in 84% of eyes. Eight eyes (13%) progressed to neovascular glaucoma and/or phthisis despite repeated surgeries.

CONCLUSION

Vitrectomy combined with antivascular endothelial growth factor therapy allows both favorable visual and anatomical outcomes in this rapidly evolving disease. Prognosis remains poor in severe stages, suggesting that the earlier the surgery performed, the better is the visual prognosis.

Surgical management of diabetic retinopathy

Surgery for late complications of proliferative diabetic retinopathy remains the cornerstone of management even in patients who have received optimal laser photocoagulation and medical therapy. With improvisation in the surgical techniques and development of micro-incision surgical techniques for vitrectomy, the indications for surgical intervention are expanding to include diabetic macular edema with a greater number of patients undergoing early intervention. This review describes the current indications, surgical techniques, adjunctive anti-vascular endothelial growth factor therapy, surgical outcomes, and postoperative complications of pars plana vitrectomy for proliferative diabetic retinopathy and macular edema.

A review of anti-VEGF agents for proliferative diabetic retinopathy

Previous research has implicated vascular endothelial growth factor (VEGF) in the pathogenesis of diabetic retinopathy (DR). Although many studies reviewed the use of anti-VEGF for diabetic macular oedema, little has been written about the use of anti-VEGF for proliferative diabetic retinopathy (PDR). This study is a review of relevant publications dealing with the use of anti-VEGF for the treatment of PDR. The articles were identified through systematic searches of PUBMED and the Cochrane Central Register of Controlled Trials. At the end of each section, we summarized the level of evidence of the scientific literature. Off-label use of anti-VEGF agents was found to be beneficial in PDR, especially in cases with neovascular glaucoma, persistent vitreous haemorrhage, and before vitrectomy. The disadvantages of the use of anti-VEGF are its short-effect duration, causing tractional retinal detachment in cases with pre-existing pre-retinal fibrosis and endophthalmitis in rare cases. There is no conclusive evidence from large randomized trials regarding the efficacy of anti-VEGF treatment in PDR. However, numerous case series, sound biochemical mechanism of action, and increasing experience with using anti-VEGF drugs can be used to support the ongoing use of this treatment modality in selected patients.

The effect of intravitreal bevacizumab as a pretreatment of vitrectomy for diabetic vitreous hemorrhage on recurrent hemorrhage

PURPOSE

This study was constructed to compare the rate of rehemorrhage in patients with diabetic vitreous hemorrhage (VH) undergoing pars plana vitrectomy (PPV) with versus without preoperative intravitreal bevacizumab (IVB) injection.

METHODS

It is a retrospective chart review of all patients who had undergone PPV for diabetic VH from January 2008 to January 2011. Patients who had undergone IVB injection before PPV were assigned to Group 1; the others were assigned to Group 2. Postoperative VH was the main outcome.

RESULTS

A total of 65 eyes of 60 patients (19 eyes in Group 1 and 46 eyes in Group 2) were examined. Postoperative VH occured in three eyes (15.8%) in Group 1 and in 13 eyes (28.3%) in Group 2, but this was not statistically significant (p: 0.347).

CONCLUSION

Further studies to evaluate the effect of IVB on postoperative VH are needed.

Anterior retinal cryotherapy and intravitreal injection of bevacizumab in the treatment of nonclearing vitreous hemorrhage in proliferative diabetic retinopathy

PURPOSE

To evaluate the efficacy of intravitreal bevacizumab (IVB) injection combined with anterior retinal cryotherapy (ARC) in the treatment of proliferate diabetic retinopathy (PDR) with vitreous hemorrhage (VH).

METHODS

A retrospective case controlled study was performed on 67 cases (67 patients) with PDR and persistent VH obscuring the fundus detail for ≧3 weeks. The follow-up period was ≧6 months. Cases with extensive vitreo-retinal adhesion by ultrasonography were excluded. In the study group, transconjunctival ARC (a total of 12 spots) followed by IVB 1.25 mg was performed in the same setting; in the control group, only IVB was given. Panretinal photocoagulation was performed when possible. Repeated IVB was performed in both groups if VH persisted for >4 weeks following the initial treatment. Vitrectomy was performed if VH showed no improvement for 12 to 16 weeks. The vitreous clear-up time (VCUT) in the posterior pole and the rate of vitrectomy were compared between the 2 groups.

RESULTS

In the study group (n=35), second treatment was required in 7 out of 35 patients (20.0%). Vitrectomy was performed in 5 (14.3%) patients. In the control group (n=32), 8 out of 32 eyes (25.0%) underwent second injection. Four eyes (12.5%) had vitrectomy within the follow-up time. VCUT in the study and the control group was 6.9±8.7 weeks and 13.0±9.3 weeks respectively (P=0.003).

CONCLUSION

Combined treatment of ARC and IVB is associated with more rapid clearing of VH in eyes with PDR compared with IVB alone.

[Use of bevacizumab in the treatment of complicated proliferative diabetic retinopathy]

INTRODUCTION

Diabetes is the leading cause of neovascular vitreoretinal proliferation. Several recent publications have appeared showing the efficacy and safety of intravitreal bevacizumab (IVT) in proliferative or complicated diabetic retinopathy (PDR), but with no consensus on the injected dose. We report the results of its use as adjuvant intravitreal injection (IVT) prior to posterior vitrectomy in the setting of complicated PDR. The goal of our work is to evaluate the benefits of and try to establish a protocol for proper use of intravitreal bevacizumab prior to vitrectomy for complicated PDR, so as to incorporate it in the management of this disease.

PATIENTS AND METHODS

A prospective comparative study of series of patients hospitalized for severe complicated PDR requiring vitrectomy was spread over one year, from January 2011 to December 2011. Included patients were divided into two groups: group A: receiving an injection preoperatively at a dose of 1.25mg, and group B, which received an injection of bevacizumab at a dose of 0.75mg (with a time to surgery of either less than 3 days, more than 6, or 3 to 6). We analyzed the epidemiological characteristics, data from the initial eye examination and intraoperative complications and follow-up after vitrectomy.

RESULTS

Thirty-five patients were included. We noted no significant difference in epidemiological characteristics between group A and B. Sixty percent of patients underwent surgery after a period of three to six days post-IVT. The reduction of neovascularization, decreased risk of bleeding and the facilitation of membrane peeling during surgery were significantly similar between group A and B. No complication related to the molecule and no recurrence, including bleeding, were noted throughout follow-up in both groups.

CONCLUSION

We opt for a systematic use of anti-VEGF, particularly bevacizumab prior to all vitrectomies for complicated PDR. A 0.75mg dose at an interval of 3 to 6 days seems to be a good compromise between the desired effect and possible complications that may arise.

Vitrectomy with or without preoperative intravitreal bevacizumab for proliferative diabetic retinopathy: a meta-analysis of randomized controlled trials

PURPOSE

To compare safety and functional outcomes of vitrectomy with or without preoperative intravitreal bevacizumab (IVB) for proliferative diabetic retinopathy (PDR).

DESIGN

A meta-analysis of randomized controlled trials.

METHODS

PubMed, Medline, EMBASE, and Cochrane Controlled Trials Register were searched to identify potentially relevant randomized controlled trials. A total of 394 participants with 414 eyes in 8 trials were analyzed using RevMan 5.1 software. The primary measures included intraoperative bleeding, total surgical time, and early and late recurrent hemorrhage.

RESULTS

Vitrectomy with IVB pretreatment achieved shorter overall surgical time (mean difference = -26.89 minutes, 95% confidence interval [CI] -31.38 to -22.39, P < .00001) and smaller number of endodiathermy applications (mean difference = -3.46, 95% CI -6.43 to -0.49, P = .02) compared to vitrectomy alone. The IVB group was also associated with less intraoperative bleeding (odds ratio [OR] = 0.10; 95% CI 0.02 to 0.46; P = .003) and recurrent vitreous hemorrhage within first month (OR = 0.35; 95% CI 0.21 to 0.58; P < .0001), but the proportion of recurrent vitreous hemorrhage after the first month was comparable between both groups. There were no significant differences in other complication rates between the 2 groups, with the exception of iatrogenic retinal break, which was more likely with the vitrectomy-alone group (OR = 0.27, 95% CI 0.12 to 0.63, P = .003). Results were robust to sensitivity analyses.

CONCLUSIONS

Adjuvant intravitreal injection of bevacizumab prior to vitrectomy in PDR patients significantly eased the procedure, diminished intraoperative complications, and reduced early postoperative hemorrhage without increasing the risk of vision-threatening complications. Further trials should determine the optimal interval and dosage for IVB injection.

The role of intraoperative bevacizumab for prevention of postoperative vitreous hemorrhage in diabetic vitreous hemorrhage

PURPOSE

To assess the effect of intravitreal bevacizumab (IVB) on the incidence of postoperative recurrent vitreous hemorrhage (VH) in eyes operated for diabetic VH when injected at the end of the surgery.

METHODS

A prospective, comparative clinical trial was conducted on a consecutive series of patients requiring vitrectomy for diabetic nonclearing VH. Intravitreal bevacizumab (2.5 mg/0.1 mL) was injected at the completion of surgery. Patients underwent best-corrected visual acuity (VA), applanation tonometry, and biomicroscopic anterior and posterior segment evaluation for VH grading. Postoperative visits were performed at the first day, first week, first month, third month, and sixth month. The VH was graded at each visit, and the rate of postoperative VH and VA improvement and potential complications were evaluated and compared between the groups.

RESULTS

A total of 72 eyes of 66 patients were included. Thirty-four eyes were enrolled in the IVB group and 38 eyes were enrolled in the control group. The rate of postoperative VH did not differ significantly between the groups at any postoperative visit (p>0.05). Three eyes (8.8%) in the IVB group and 5 eyes (13.1%) in the control group had postoperative VH throughout the follow-up period and only one eye from each group underwent a second surgery. Postoperative VA significantly increased in both groups but did not differ significantly between the groups at any postoperative visit (p>0.05).

CONCLUSIONS

Intravitreal bevacizumab does not seem to have any beneficial effect on the incidence of postoperative VH in eyes operated for diabetic VH when injected at the end of surgery.

Fibrovascular ingrowth after 25-gauge transconjunctival vitrectomy in proliferative diabetic retinopathy

The authors describe two patients with proliferative diabetic retinopathy bilaterally who were treated with transconjunctival 25-gauge pars plana vitrectomy (PPV) for dense vitreous hemorrhage (VH). After 4 and 10 months, respectively, both developed recurrent VH. They were initially managed with in-office gas-fluid exchange and anti-VEGF intravitreal injection. Soon after gas bubble resorption, the VH recurred. Color external photos revealed engorged episcleral vessels superotemporally, and ultrasound biomicroscopy confirmed the presence of fibrovascular ingrowth (FVI) at the sclerotomy site in both patients. They were successfully treated with a slightly modified 25-gauge PPV technique. Although FVI is well-recognized following conventional 20-gauge vitrectomy, this report is the first to detail FVI arising after small-gauge transconjunctival vitrectomy.

Elevation of angiogenic factor Cysteine-rich 61 levels in vitreous of patients with proliferative diabetic retinopathy

PURPOSE

Cysteine-rich 61 (Cyr61) is one of the angiogenic factors involved in proliferative diabetic retinopathy (PDR). To further investigate its role, we measure and compare the vitreous levels of Cyr61 and vascular endothelial growth factor in patients with PDR and to localize Cyr61 expression in associated proliferative epiretinal membranes.

METHODS

Vitreous obtained from 56 patients with active PDR, 16 patients with active PDR pretreated with bevacizumab, 19 patients with quiescent PDR, 15 non-PDR patients with diabetic macular edema, and 25 patients with non-diabetic-related eye diseases were subjected to enzyme-linked immunosorbent assay for Cyr61 and vascular endothelial growth factor levels. Epiretinal membranes from 18 patients were stained immunohistochemically for Cyr61.

RESULTS

Vitreous Cyr61 levels were significantly higher in active PDR patients, quiescent PDR patients, and diabetic macular edema patients compared with non-diabetic control patients (P < 0.01). Pretreatment of bevacizumab significantly suppressed vitreous vascular endothelial growth factor levels; however, it did not inhibit vitreous Cyr61 levels in active PDR patients. Cysteine-rich 61 was strongly detected in endothelial cells and myofibroblasts within active PDR membranes but not in idiopathic epiretinal membrane.

CONCLUSION

Vitreous Cyr61 levels were related to different states of PDR and correlated with vascular endothelial growth factor levels in PDR patients. Pretreatment of bevacizumab did not inhibit vitreous Cyr61 levels in active PDR patients. Cysteine-rich 61 might mediate angiogenesis and post-angiogenic fibrosis in PDR.

Distribution, reabsorption, and complications of preretinal blood under silicone oil after vitrectomy for severe proliferative diabetic retinopathy

PURPOSE

To examine the evolution and complications of preretinal hemorrhage under silicone oil after diabetic vitrectomy.

METHODS

A total of 44 cases of primary diabetic vitrectomy with silicone oil infusion were reviewed in a 3-year period. Intravitreal bevacizumab was used preoperatively for cases with active proliferation, and in all cases at the end of surgery. Intraoperative bleeding, postoperative extent of preretinal hemorrhage, blood reabsorption time, and reproliferation and treatment results were assessed.

RESULTS

Maximal blood distributed in thin and scattered patterns (23 cases), thick and localized patterns (10 cases), or thick and scattered patterns (10 cases) developed within 1 week after surgery, and was largely reabsorbed within a month with improved postoperative vision. Confluent blood extending to the midperiphery (one case) resulted in severe fibrosis and detachment. Complications included fibrotic plaque (two cases), and fibrous band and thick membrane (seven cases). Six cases underwent preretinal tissue removal. Vision improvement ≥ 3 lines was noted in three cases.

CONCLUSION

Most of the rebleeding occurred within the first post-op week, with gradual reabsorption in the posterior pole within 4 weeks; widespread confluent bleeding might result in severe reproliferation and detachment. A major complication of preretinal bleeding was the formation of preretinal fibrosis. Re-operation achieved a mild VA improvement.

[Intravitreal bevacizumab pretreatment in vitrectomy for severe diabetic retinopathy: a series of six cases]

INTRODUCTION

Bevacizumab (Avastin(®), Roche) is a full-length humanized monoclonal antibody applicable to all subtypes of vascular endothelial growth factor (VEGF). The purpose of this study was to report the results of its use as a surgical additive in severe cases of proliferative diabetic retinopathy (PDR).

PATIENTS AND METHOD

This retrospective study focused on six eyes of six patients with complicated diabetic retinopathy. A vitrectomy was performed within 13.6 days after an intravitreal bevacizumab injection of 0.1 mL (2.5mg), with dissection of the fibrovascular proliferation using a mono- or bimanual delamination technique.

RESULTS

The mean follow-up after intravitreal injection was 13.3 months. The mean surgery time was 64 minutes. The bimanual technique was not necessary. Only one iatrogenic retinal tear was repaired. The intraoperative bleeding was negligible. No adverse events resulting from the drug nor recurrence were observed throughout the follow-up period.

CONCLUSION

Intravitreal bevacizumab is useful as a surgical additive in severe cases of PDR, significantly improving surgical conditions. Nevertheless, its use beyond approved indications should be reserved for complex surgical cases.

Treatment of proliferative diabetic retinopathy with anti-VEGF agents

Proliferative diabetic retinopathy (PDR) is the most common cause of severe visual loss in people with diabetes. Although panretinal photocoagulation (PRP) remains the gold standard of care to date, several combinations of new treatment modalities have emerged. These approaches can be used to increase the extent of treatment, expedite the effect of laser treatment and provide alternate measures when laser delivery is difficult or impossible, especially in patients with vitreous haemorrhage. Currently, most of the research in this field is focussed on inhibitors of vascular endothelial growth factor (VEGF), referred to herein as anti-VEGF agents. Although limited by their short-lived effects and a lack of established protocols, anti-VEGF agents are widely available, especially for the treatment of aggressive PDR. This review analyses published studies using anti-VEGF agents alone or as an adjunct to other therapies in the treatment of PDR.

Bevacizumab prior to vitrectomy for diabetic traction retinal detachment

PURPOSE

To assess the efficacy and safety of preoperative intravitreal bevacizumab (IVB) before vitrectomy for diabetic tractional retinal detachment (TRD).

METHODS

Using ICD-9 codes, we located all patients with diabetic TRD who underwent 3-port 20-gauge vitrectomy primarily performed by one surgeon between January 2004 and January 2009. Eyes receiving IVB were compared with those not. The following outcomes were compared: visual acuity (VA), duration of surgery, and complication rates.

RESULTS

A total of 99 eyes of 90 patients were included in the analysis. In all, 34 patients received IVB on an average of 11.5 (range, 3-30) days previtrectomy. Age was 46.5 and 51.6 in the IVB and non-IVB groups, respectively. VA was improved significantly in both groups: from 20/617 to 20/62 in the IVB group, and from 20/443 to 20/86 in the non-IVB group (P=0.11 between groups). Operating time and postoperative complications (glaucoma, RD, and revitrectomy rate) were similar in both groups. On comparing IVB and non-IVB eyes in younger patients (≤ 40), operating time was shorter (P=0.02) and a trend to better VA in the IVB group was seen.

CONCLUSIONS

Preoperative IVB may be a useful adjunct to vitrectomy for severe PDR complicated by TRD, particularly in younger diabetics.

Diabetic retinopathy: pathogenic mechanisms and current treatments

Since diabetes is now a global epidemic, the incidence of retinopathy, a leading cause of blindness in patients aged 20-74 years, is also expected to rise to alarming levels. The risk of development and progression of diabetic retinopathy is closely associated with the type and duration of diabetes, blood glucose, blood pressure and possibly lipids. It is an unmet medical need that can lead to severe and irreversible loss of vision in people of working age worldwide. The aim of this review is to give an overview of the clinical and anatomical changes during the progression of retinopathy, the underlying pathogenic mechanisms that link hyperglycemia with retinal tissue damage, current treatments, and the emerging pharmacological therapies for this sight-threatening complication of diabetes.

Anti-vascular endothelial growth factor for prevention of postoperative vitreous cavity haemorrhage after vitrectomy for proliferative diabetic retinopathy

BACKGROUND

Postoperative vitreous cavity haemorrhage (POVCH) is a significant complication following vitrectomy for proliferative diabetic retinopathy (PDR). It delays visual recovery and can make further treatment difficult if the view of the fundus is significantly obscured. A number of interventions to reduce the incidence of POVCH have been proposed, including the perioperative use of anti-vascular endothelial growth factor (anti-VEGF). Anti-VEGFs reduce vascular proliferation and the vascularity of neovascular tissue, which is often the source of bleeding following vitrectomy.

OBJECTIVES

The review aims to assess the effect of perioperative anti-VEGF in reducing the incidence of POVCH.

SEARCH STRATEGY

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 2), MEDLINE (January 1950 to March 2011), PubMed (10 March 2011), EMBASE (January 1980 to March 2011), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to March 2011), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov (www.clinicaltrial.gov). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 10 March 2011.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that looked at the use of anti-VEGFs and the incidence of POVCH in people undergoing vitrectomy for PDR.

DATA COLLECTION AND ANALYSIS

Both review authors independently assessed and extracted the data using a standardised form based on the CONSORT statement.

MAIN RESULTS

We included four studies (202 eyes of 198 participants) in this review. The four RCTs met the inclusion criteria, but we were unable to conduct a meta-analysis due to methodological issues in three of the trials. We have provided a summary of the effects of the interventions. We have also provided a summary of the current literature addressing each primary and secondary outcome.

AUTHORS' CONCLUSIONS

Results from one of the included studies support the use of preoperative intravitreal bevacizumab to reduce the incidence of early POVCH. There are currently no other high quality RCTs that support the use of anti-VEGF agents perioperatively to reduce the incidence of early or late POVCH. The remaining studies identified by the search suggest that the preoperative use of bevacizumab may reduce the incidence of early POVCH, but it should be recognised that there are a number of significant methodological issues in these studies that lead us to be cautious when interpreting their findings and make any definitive conclusions unwarranted.

Role of intravitreal bevacizumab (Avastin) injected at the end of diabetic vitrectomy in preventing postoperative recurrent vitreous hemorrhage

PURPOSE

The purpose of this study was to evaluate the role of bevacizumab (Avastin), an antivascular endothelial growth factor agent, injected at the end of surgery for preventing postoperative recurrent vitreous hemorrhage in patients undergoing vitrectomy for diabetic eye disease.

METHODS

This was a retrospective, comparative, and nonrandomized study on a consecutive series of patients who underwent vitrectomy for diabetic eye disease. Recurrence of postoperative vitreous hemorrhage was compared in patients with and without intravitreal 1.25 mg bevacizumab given at the end of surgery.

RESULTS

During the study period, 58 patients had vitrectomy for diabetic disease. In 33 patients (the control group), no intravitreal bevacizumab was injected at the end of surgery, and in 25 patients (the intervention group) intravitreal bevacizumab 1.25 mg/0.05 mL was injected at the end of surgery. Both groups were matched for the number of patients, age, sex, diagnosis, and status of systemic disease. Recurrent postoperative vitreous hemorrhage was noted in 14 patients in the control group (14 of 33, 42.40%) and in 1 patient in the intervention group (1 of 25, 4.0%). The difference in postoperative vitreous hemorrhage between the 2 groups was statistically significant (P = 0.001). There was no statistical difference in the mean postoperative visual acuity between the 2 groups during the follow-up period (P = 0.410).

CONCLUSION

Intravitreal injection of 1.25 mg bevacizumab given at the end of vitrectomy appears safe and effective for reducing the incidence of recurrent postoperative vitreous hemorrhage after diabetic vitrectomy. Further randomized studies should be performed to evaluate the potential of this therapy in preventing postoperative recurrent vitreous hemorrhage after diabetic vitrectomy.

A systematic review and meta-analysis of clinical outcomes of vitrectomy with or without intravitreal bevacizumab pretreatment for severe diabetic retinopathy

Aims

To examine possible benefits of intravitreal bevacizumab (IVB) pretreatment in vitrectomy for severe diabetic retinopathy.

Methods

A comprehensive literature search was performed using the Cochrane Collaboration methodology to identify randomised controlled trials and comparative studies of vitrectomy with or without IVB pretreatment for severe or complicated diabetic retinopathy. Meta-analyses were performed for intraoperative (including intraoperative bleeding, endodiathermy, iatrogenic retinal tears and mean surgical time) and postoperative outcome parameters (including best-corrected visual acuity, recurrent vitreous haemorrhage, reabsorption time of blood and other complications).

Results

Six randomised controlled trials and one comparative study were identified and used for comparing vitrectomy alone (142 eyes, control group) with vitrectomy with IVB pretreatment (139 eyes). The intraoperative findings showed that the incidence of intraoperative bleeding and frequency of endodiathermy were statistically significantly less in the IVB pretreatment group (p<0.01) than in the vitrectomy alone group. The IVB pretreatment group took significantly less surgical time than the control group (p=0.003). Postoperative results indicated that reabsorption time of blood was significantly shorter (p=0.04), incidence of recurrent VH was almost significantly less (p=0.05), and final best-corrected visual acuity was significantly better (p=0.003) in the IVB group than in the control group. Other complications, including final retinal detachment, and reoperation, were statistically insignificant.

Conclusion

IVB pretreatment in vitrectomy can achieve excellent clinical outcomes for severe diabetic retinopathy. It potentially facilitates surgeons' manoeuvres and reduces intra- and postoperative complications.

Current concepts in intravitreal drug therapy for diabetic retinopathy

Diabetic retinopathy (DR) is a major cause of preventable blindness in the developed countries. Despite the advances in understanding and management of DR, it remains a challenging condition to manage. The standard of care for patients with DR include strict metabolic control of hyperglycemia, blood pressure control, normalization of serum lipids, prompt retinal laser photocoagulation and vitrectomy. For patients who respond poorly and who progressively lose vision in spite of the standard of care, intravitreal administration of steroids or/and anti-vascular endothelial growth factor (anti-VEGF) drugs appear to be a promising second-line of therapy. This review discusses the current concepts and the role of these novel therapeutic approaches in the management of DR.

Use of pegaptanib for recurrent and non-clearing vitreous haemorrhage in proliferative diabetic retinopathy

PURPOSE

Diabetes is the leading cause of blindness in the United Kingdom among people of working age. Many with proliferative diabetic retinopathy (PDR) go on to develop vitreous haemorrhage (VH). Those with recurrent or non-clearing VH require vitrectomy to restore vision. Pegaptanib is a vascular endothelial growth factor antagonist that disrupts the proliferative cascade and has been shown to precipitate regression of retinal neovascularisation. We assessed the effect of pre-operative intravitreal (IVT) pegaptanib on the timing, difficulty, and outcome of vitrectomy for recurrent VH in PDR.

METHODS

Fourteen consecutive patients (15 eyes) were given a course of 1-3 IVT pegaptanib injections and vitrectomy was performed when indicated by the recurrence or persistence of VH, or progression of associated tractional retinal detachment (TRD).

RESULTS

The range of patient follow-up was from 6 months to 2 years. All had no further VH for at least 4 weeks after IVT pegaptanib. Five eyes remained free from VH until the end of the study (8-25 months), thus obviating the need for vitrectomy. Two further cases avoided vitrectomy following further IVT pegaptanib. In the majority of patients with VH, IVT pegaptanib created a window for further laser and risk factor optimisation. Surgery was faster and less challenging, compared with conventional vitrectomy for recurrent VH due to PDR.

CONCLUSIONS

IVT pegaptanib can be considered in diabetic patients with VH. Approximately one-third may avoid vitrectomy altogether. There are clear intra-operative advantages of using IVT pegaptanib pre-operatively. However, caution should be exercised where there is pre-existing TRD.

A review of clinical trials of anti-VEGF agents for diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) is a leading cause of vision loss in the working-age population worldwide. Many observational and preclinical studies have implicated vascular endothelial growth factor (VEGF) in the pathogenesis of DR, and recent successes with anti-VEGF therapy for age-related macular degeneration (AMD) have prompted research into the application of anti-VEGF drugs to DR. Here we review the numerous early studies that suggest an important potential role for anti-VEGF agents in the management of diabetic retinopathy.

CONCLUSIONS

For diabetic macular edema, phase II trials of intravitreal pegaptanib and intravitreal ranibizumab have shown short-term benefit in visual acuity. Intravitreal bevacizumab also has been shown to have beneficial short-term effects on both visual acuity and retinal thickness. For proliferative diabetic retinopathy (PDR), early studies suggest that intravitreal bevacizumab temporarily decreases leakage from diabetic neovascular lesions, but this treatment may be associated with tractional retinal detachment (TRD). Furthermore, several studies indicate that bevacizumab is likely to prove a helpful adjunct to diabetic pars plana vitrectomy (PPV) for TRD. Finally, three small series suggest a potential beneficial effect of a single dose of bevacizumab to prevent worsening of DME after cataract surgery. Use of anti-VEGF medications for any of these indications is off-label. Despite promising early reports on the safety of these medications, we eagerly await the results of large, controlled trials to substantiate the safety and efficacy of anti-VEGF drugs for diabetic retinopathy.

Intravitreal bevacizumab and panretinal photocoagulation for proliferative diabetic retinopathy associated with vitreous hemorrhage

PURPOSE

To evaluate the efficacy of intravitreal bevacizumab with panretinal photocoagulation (PRP) in the treatment of proliferate diabetic retinopathy (PDR) with vitreous hemorrhage (VH).

METHODS

Forty cases (40 patients) with PDR and persistent VH were prospectively enrolled, with a follow-up period of 12 months or more. Intravitreal bevacizumab injection (1.25 mg) was given, followed by PRP when visualization of peripheral fundus could be obtained. A second injection was administered 4 weeks to 6 weeks after the first injection if no signs of VH decrease were noted. Vitrectomy was performed if VH persisted >12 weeks. The vitreous clear-up time (VCUT) and the rate of vitrectomy were compared with those in a historical control group (40 eyes in 40 patients) who were treated with conventional methods.

RESULTS

Thirty-one eyes had 1 injection and 9 eyes (22.5%) received 2 injections. Vitreous clear-up time in the study and control groups were 11.9 +/- 9.5 weeks and 18.1 +/- 12.7 weeks (P = 0.02), respectively. Rates of required vitrectomy were 10% in the study group and 45% in the control group (P = 0.01).

CONCLUSION

One or 2 intravitreal injections of 1.25 mg bevacizumab with PRP are associated with rapid regression of VH and may reduce the need for vitrectomy.

Can an intraoperative bevacizumab injection prevent recurrent postvitrectomy diabetic vitreous hemorrhage?

PURPOSE

To evaluate the recurrence of vitreous hemorrhage (VH) in patients treated with intravitreal bevacizumab (IVB) injection (2.5 mg/0.1 mL) intraoperatively at the end of vitrectomy for treatment of diabetic nonclearing VH.

METHODS

A prospective pilot study of 30 eyes of 28 consecutive diabetic patients who underwent pars plana vitrectomy and IVB injection intraoperatively at the end of vitrectomy was performed. The amount of VH was graded with slit lamp biomicroscopy by three masked retinal specialists from grade 0 to grade 3. Main outcome measures were rate of recurrence of the VH, improvement in visual acuity, incidence of cataract formation, and postoperative complications through a follow-up of 6 months.

RESULTS

The percentage of severe recurrent VH with no fundus details (grade 3) was 7%, 13%, 27%, and 30%, respectively, at 7 days and 1-, 3-, and 6-month follow-up. At 6-month followup, the best-corrected visual acuity improved from 1.00 to 0.4 logMAR (p=0.01) in 21 out of 30 eyes (70%). Nine out 20 (40%) phakic patients developed cataract during the follow-up period, and 7 (31%) of them underwent cataract surgery.

CONCLUSIONS

The study suggests that intravitreal bevacizumab injection cannot prevent rebleeding in eyes undergoing pars plana vitrectomy for treatment of diabetic vitreous hemorrhage.

Visual outcomes and incidence of recurrent vitreous hemorrhage after vitrectomy in diabetic eyes pretreated with bevacizumab (avastin)

PURPOSE

To evaluate the safety and effect of bevacizumab pretreatment on the incidence of recurrent vitreous hemorrhage and visual acuity after vitrectomy for proliferative diabetic retinopathy.

METHODS

This was a consecutive, retrospective, and comparative cohort study. Patients undergoing vitrectomy from September 2006 through November 2007 at the Emory Eye Center for complications of proliferative diabetic retinopathy were identified and reviewed. A total of 33 eyes pretreated with bevacizumab and 104 untreated eyes were observed for postoperative vitreous hemorrhage and final visual acuity.

RESULTS

Patients in the bevacizumab group were significantly younger than those in the untreated group (average age, 46.4 vs. 58.4 years) and were more likely to have 20-gauge instrumentation (58% vs. 36%). An average of 9.6 days passed between injection and surgery. Early (4-6 weeks) rebleed rates were 15% versus 13% in the bevacizumab and untreated groups, respectively, and not statistically different. Preoperative (7/200 vs. count finger at 4'), 1-month postoperative (20/200(-3) vs. 20/150), and 3-month postoperative visual acuity (20/100(-3) vs. 20/100(+2)) were not statistically different between groups. No statistical difference was found in rebleed rates regarding the gauge of vitrectomy.

CONCLUSION

Bevacizumab pretreatment for diabetic vitrectomy was not associated with any observed complications but did not influence rates of postoperative vitreous hemorrhage or final visual acuity in this retrospective series. The overall incidence of postoperative early vitreous hemorrhage in this series was 13% and seems lower than historically reported rates.

Bevacizumab (Avastin) for the treatment of ocular disease

The use of intravitreal bevacizumab (Avastin) has greatly expanded since its introduction into ophthalmic care 3 years ago. A PubMed search on 1 August 2008 revealed 51 ocular disease processes that have been treated with bevacizumab. The majority of publications consist of case reports or retrospective case series and their number is increasing quickly. It is important to collate the experiences gained to date to properly inform our clinical decision making and improve the design of future clinical trials. Current studies cannot easily be combined in a meta-analysis given the lack of standardized data and the wide variety of disorders studied in small numbers. This paper will describe the attempted uses of intravitreal bevacizumab and its efficacy for each ocular disease in addition to discussing safety. Comments regarding appropriate use of this treatment are based on our current level of knowledge. It is clear that the initial encouraging results described in this paper warrant further study of intravitreal bevacizumab in larger, controlled, randomized trials.