Six-month visual outcome after pars plana vitrectomy in proliferative diabetic retinopathy with or without a single preoperative injection of intravitreal bevacizumab

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.

Outcomes of Pars Plana Vitrectomy with Panretinal Photocoagulation for Treatment of Proliferative Diabetic Retinopathy Without Retinal Detachment: A Seven-Year Retrospective Study

Objective

To review clinical outcomes of patients with proliferative diabetic retinopathy (PDR) and vitreous hemorrhage (VH) who underwent pars plana vitrectomy (PPV) with endolaser panretinal photocoagulation (PRP) without retinal detachment (RD) repair.

Methods

Retrospective chart review of the rate of postoperative clinical findings and visual acuity in patients with PDR from May 2014 to August 2021.

Results

Pars plana vitrectomy with endolaser PRP was performed in 81 eyes of 81 patients (mean age of 62.1 ± 10.5 years). At a median follow-up of 18 months, mean Snellen best-corrected visual acuity (BCVA) significantly improved from 20/774 preoperatively to 20/53 at last follow-up (P < 0.001). Postoperative complications and clinical findings included VH (12.3%), diabetic macular edema (DME) (12.3%), ocular hypertension (8.6%), RD (4.9%), and need for additional PPV (6.2%). Eyes with PRP performed within 6 months before surgery had a lower frequency of developing postoperative VH (5.3%) compared to eyes that received PRP more than 6 months before surgery (27.3%, P = 0.04). Eyes that received preoperative anti-vascular endothelial growth factor (VEGF) treatment (2.0%) had a lower frequency of postoperative VH compared to eyes that did not receive anti-VEGF treatment (14.3%, P = 0.04). Eyes that received intraoperative sub-tenon triamcinolone acetonide developed postoperative DME (4.0%) less frequently than eyes that did not receive sub-tenon triamcinolone acetonide (26.7%, P = 0.04).

Conclusion

In patients with PDR and VH, PPV with PRP yielded significant improvements in visual acuity and resulted in overall low rates of recurrent postoperative VH. Preoperative anti-VEGF and PRP laser treatment were associated with lower rates of postoperative VH. Furthermore, intraoperative use of sub-tenon triamcinolone acetonide was associated with a lower rate of postoperative DME. Pars plana vitrectomy with endolaser PRP in conjunction with the aforementioned pre- and intraoperative therapies is an effective treatment for patients with PDR and VH.

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

Potential bias of preoperative intravitreal anti-VEGF injection for complications of proliferative diabetic retinopathy

PURPOSE

Intravitreal anti-VEGF injection (IVI) is administered before vitrectomy to assist management of proliferative diabetic retinopathy (PDR)-related complications. In the clinical setting, retinal surgeons determine the use of preoperative IVI based on individual criteria. In this study, we investigated factors related to the potential bias of retinal surgeons in using IVI prior to vitrectomy for PDR-related complications, and evaluated the real-world outcomes of surgeon-determined preoperative IVI.

METHODS

Medical records of 409 eyes of 409 patients who underwent 25-gauge vitrectomy for PDR complications at seven Japanese centers (22 surgeons) were retrospectively reviewed. Ocular factors, demographic and general clinical factors, surgical procedures, and postoperative complications were compared between IVI group (patients who received preoperative IVI; 87 eyes, 21.3%) and non-IVI group (patients who did not receive preoperative IVI; 322 eyes, 78.7%). In addition, baseline HbA1c in IVI group and non-IVI group was compared between eyes with and without postoperative complications.

RESULTS

At baseline, IVI group was younger (P<0.001), had shorter duration of diabetes treatment (P = 0.045), and higher frequencies of neovascular glaucoma [NVG] (P<0.001) and tractional retinal detachment [TRD] (P<0.001) compared to non-IVI group. Although IVI group had higher frequencies of intraoperative retinal break and tamponade procedure, there were no significant differences in postoperative complications and additional treatments between two groups. Baseline HbA1c levels were also not correlated with postoperative complications of VH, NVG, and RD both in IVI group and non-IVI group. Logistic regression analysis identified age (P<0.001, odds ratio [OR] 0.95), presence of NVG (P<0.001, OR 20.2), and presence of TRD (P = 0.0014, OR 2.44) as preoperative factors in favor of IVI.

CONCLUSIONS

In this multicenter real-world clinical study, younger age and presence of NVG and TRD were identified as potential biases in using IVI before vitrectomy for PDR complications. Eyes that received preoperative IVI had more intraoperative retinal breaks requiring tamponade than eyes not receiving IVI, but postoperative outcome was not different between the two groups.

Anti-Vascular Endothelial Growth Factor Therapy as an Adjunct to Diabetic Vitrectomy

Introduction:

The purpose of this work is to study the efficacy of the preoperative intravitreal administration of bevacizumab as an adjunct to vitrectomy in patients with Proliferative Diabetic Retinopathy (PDR).

Methods:

This retrospective comparative study was performed on 118 eyes (118 patients) with proliferative diabetic retinopathy (PDR), which underwent vitrectomy surgery at the Department of Diabetic Eye Disease at Zarifa Aliyeva National Ophthalmology Centre (Baku, Azerbaijan) in 2015-2019. The main group (the bevacizumab group) included 48 eyes with PDR that received intravitreal administration of bevacizumab (Avastin; Genentech Inc., USA) within one week before vitrectomy; the control group included 70 eyes that did not receive a bevacizumab injection for at least 3 months before the vitrectomy. The minimum follow-up was 12 months.

Results:

In both groups, complete retinal attachment after primary vitrectomy was achieved in all eyes (100%). Clinically significant intraoperative haemorrhage was observed in the preoperative bevacizumab injection group in 31.2% and the control group- 51.4%, p = 0.030. The preoperative bevacizumab injection reduced the risk of clinically significant haemorrhage by 2.3 times and the need for endodiathermy by 2.7 times (p = 0.031 and p = 0.024, respectively). Early vitreous cavity haemorrhage was observed in 15.0% in the bevacizumab group and in 35.5% in the control group (p = 0.038). The preoperative injection of bevacizumab before vitrectomy reduced the risk of vitreous cavity haemorrhage in the early postoperative period by 3.0 times (p = 0.036).

Conclusion:

The preoperative use of bevacizumab as an adjunct to diabetic vitrectomy can help reduce the incidence of intraoperative and early postoperative vitreous cavity haemorrhage, which leads to better functional results in the early postoperative period. Over the long-term follow-up period, the effect of the preoperative bevacizumab injections decreases.

An optimized segmentation and quantification approach in microvascular imaging for OCTA-based neovascular regression monitoring

Background

Quantification of neovascularization changes in terms of neovascular complex (NVC) acquired from the optical coherence tomography angiography (OCTA) imaging is extremely important for diagnosis and treatment monitoring of proliferative diabetic retinopathy (PDR). However, only few vessel extraction methods have so far been reported to quantify neovascular changes in NVC with proliferative diabetic retinopathy PDR based on OCTA images.

Methods

Here we propose an optimized approach to segment blood vessels, which is based on an improved vascular connectivity analysis (VCA) algorithm and combined with morphological characterization and elimination of noise and artifacts. The length and width of vessels are obtained in the quantitative assessment of microvascular network. The feasibility of the proposed method is further studied by a treatment monitoring and statistical analysis process, as we have monitored and statistically analyzed the changes of NVC based on sampled OCTA images of PDR patients (N = 14) after treatment by intravitreal injection of conbercept.

Results

The proposed method has demonstrated better performance in accuracy compared with existing algorithms and can thus be used for PRD treatment monitoring. Following the PDR treatment monitoring study, our data has shown that from the 1st day to 7th day of treatment, the averaged (arithmetic mean) length of NVC has been substantially shortened by 36.8% (P < 0.01), indicating significant effects of treatment. Meanwhile, the averaged (arithmetic mean) width of NVC from the 1st day to 7th day of treatment has been increased by 10.2% (P < 0.05), indicating that most of the narrow neovascularization has been reduced.

Conclusion

The results and analysis have confirmed that the proposed optimization process by the improved VCA method is both effective and feasible to segment and quantify the NVC with lower noise and fewer artifacts. Thus, it can be potentially applied to monitor the fibrovascular regression during the treatment period.

Clinical Trial Registration This trial is registered with the Chinese Clinical Trial Registry (Registered 27 December 2017, http://www.chictr.org.cn, registration number ChiCTR-IPR-17014160).

Perioperative anti-vascular endothelial growth factor agents treatment in patients undergoing vitrectomy for complicated proliferative diabetic retinopathy: a network meta-analysis

Currently, controversies regarding the optimal time-point of anti-vascular endothelial growth factor (VEGF) pretreatment before pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR) still exist. To clarify this, we conducted a network meta-analysis, 26 randomized controlled trials including 1806 PDR patients were included. Compared with the sham group, performing anti-VEGF injection at preoperative (Pre-Op) 6 to 14 days could significantly improve post-operative best-corrected visual acuity (BCVA) and decrease the incidence of recurrent vitreous hemorrhage (VH). Meanwhile, it could significantly reduce the duration of surgery. Performing anti-VEGF injection at Pre-Op more than 14 days, 6 to 14 days or 1 to 5 days could significantly reduce the incidence of intra-operative bleeding, while no significant benefit existed at the end of PPV (P > 0.05). No significant difference existed between all those strategies and sham group in reducing the rate of silicone oil tamponade. Based on currently available evidence, performing the anti-VEGF pretreatment at pre-operative 6 to 14 days showed best efficacy in improving post-operative BCVA, reducing the duration of surgery and incidence of recurrent VH, it also achieves satisfactory effect in reducing the incidence of intra-operative bleeding.

Preoperative Bevacizumab for Tractional Retinal Detachment in Proliferative Diabetic Retinopathy: A Prospective Randomized Clinical Trial

PURPOSE

To assess the effectiveness and safety of an intravitreal injection of 1.25 mg bevacizumab (IVB) as a preoperative adjunct to small-gauge pars plana vitrectomy (PPV) compared with PPV alone in eyes with tractional retinal detachment secondary to proliferative diabetic retinopathy.

METHODS

This prospective, double-masked, randomized, multicenter, active-controlled clinical trial enrolled 224 eyes of 224 patients between November 2013 and July 2015. All eyes underwent a baseline examination including best-corrected visual acuity, color photos, optical coherence tomography, and fluorescein angiography. Data were collected on intraoperative bleeding, total surgical time, early (<1 month) postoperative vitreous hemorrhage, and mean change in best-corrected visual acuity at 12 months. P < .05 was considered statistically significant.

RESULTS

A total of 214 patients (214 eyes) were randomized in a 1:1 ratio to PPV plus IVB ([study group] 102 eyes) or PPV plus sham ([control] 112 eyes). Iatrogenic retinal breaks were noted intraoperatively in 35 eyes (34.3%) in the study group, and 66 eyes (58.9%) in the control group (P = .001). Grade 2 intraoperative bleeding was noted in 32 (31.3%) eyes in the study group and 58 (51.7 %) eyes in the control group (P = .001). Endodiathermy was necessary in 28 (27.4 %) eyes in the study group, compared with 75 (66.9%) eyes in the control group (P = .0001). Mean surgical time was 71.3 ± 32.1 minutes in the study group and 83.6 ± 38.7 minutes in the control group (P = .061).

CONCLUSION

Preoperative IVB seems to reduce intraoperative bleeding, improving surgical field visualization, and reducing intraoperative and postoperative complications. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Surgical management of diabetic tractional retinal detachments

Tractional retinal detachment is an end-stage form of diabetic retinopathy that occurs when contractile forces in the vitreous and neovascular tissue lead to the detachment of the neurosensory retina. We review the literature related to the management of this disease. Preoperative planning includes appropriate patient selection, diagnostic and prognostic imaging, and medical optimization with reduction of systemic risk factors. Use of antivascular endothelial growth factor for preoperative treatment has had significant benefits for tractional retinal detachment repair in improving surgical efficiency and outcomes. Advances in microsurgical instrumentation are discussed, with attention to small-gauge vitrectomy with improved flow dynamics, viewing strategies, and lighting allowing bimanual surgery. Special emphasis is placed on bimanual surgical technique, choice of tamponade, and the avoidance of iatrogenic damage. Complications and special considerations are further explored. Based on our compilation of relevant literature, we propose a surgical algorithm for the management of these complex patients.

OCT angiography-based monitoring of neovascular regression on fibrovascular membrane after preoperative intravitreal conbercept injection

PURPOSE

To quantify the preoperative neovascular change pattern on the fibrovascular membrane (FVM) within 7 days after intravitreal injection of conbercept (IVC) using optical coherence tomography angiography (OCTA) in proliferative diabetic retinopathy (PDR).

METHODS

Prospective, observational study of PDR patients with visible FVM receiving or not receiving IVC. Neovascular changes were assessed by OCTA pre-IVC and 1, 3, 5, and 7 days post-IVC. Vessel skeleton density (SD) and vessel density (VD) were quantified by an intensity-based optical microangiography algorithm. The interclass correlation coefficient (ICC) was calculated to assess the agreement between measurements. The SD and VD were compared between follow-ups using repeated-measures analysis in the IVC group.

RESULTS

The ICC was 0.992 (95% confidence interval [CI]: 0.982-0.996) for SD and 0.926 (95% CI: 0.838-0.912) for VD of neovascularization. The neovascularization on FVM significantly regressed in the IVC group (n = 16) compared with no IVC (n = 8) (p = 0.001 for SD and p < 0.001 for VD). The comparisons between consecutive follow-ups showed a statistically significant reduction in SD and VD at 1 and 3 days post-IVC. However, from day 3 onward, the SD and VD remained unchanged. There was no development or progression of tractional retinal detachment within the 7-day period after IVC.

CONCLUSION

OCTA-based quantification of the neovascularization on FVM in PDR is feasible, with high inter-reader agreement. The regression of neovascularization reaches a plateau 3 days after IVC.

CLINICAL TRIAL REGISTRATION

This trial is registered with the Chinese Clinical Trial Registry ( http://www.chictr.org.cn , registration number ChiCTR-IPR-17014160).

Characteristics and Outcomes of Pars Plana Vitrectomy for Proliferative Diabetic Retinopathy Patients in a Limited Resource Tertiary Center over an Eight-Year Period

Purpose

To report characteristics and visual results in patients with PDR-associated complications following pars plana vitrectomy (PPV) in a tertiary center over an eight-year period.

Methods

Medical records of diabetic retinopathy patients receiving PPV between January 2007 and December 2014 for PDR-related complications were reviewed.

Results

A total of 890 consecutive PDR patients were included in the study. PPVs were performed for tractional retinal detachment (36.6%), persistent vitreous hemorrhage (VH) (35.4%), combined tractional and rhegmatogenous retinal detachment (14.5%), and vitreoretinal abnormalities (13.5%), respectively. Preoperative intravitreal bevacizumab injection (IVB) within two weeks prior to PPV and 23G vitrectomy systems was found to decrease the risk for intraoperative retinal break development (P=0.045 and P=0.015, respectively). The incidence of early dense postoperative VH decreased significantly with the administration of preoperative or intraoperative IVB at the end of PPV. Postoperative visual results significantly correlated with the initial visual acuity level, intraoperative retinal break development, and retained silicone oil tamponade at the final visit (P < 0.001, P=0.040, and P=0.044, respectively). Administration of adjuvant IVB either before or at the end of PPV had no significant association with the final visual outcomes.

Conclusions

This study reported an improvement in visual acuity in nearly half of patients receiving PPV for PDR-associated complications in a limited resource center. The incidence of intraoperative retinal break and early postoperative VH decreased significantly with the application of IVB injections. Poor final visual outcomes were related to the lower initial visual acuity levels, intraoperative retinal breaks, and postoperative retained silicone oil.

Safety and efficacy of intravitreal conbercept injection after vitrectomy for the treatment of proliferative diabetic retinopathy

BACKGROUND/OBJECTIVES

The aim of this study was to evaluate the safety and efficacy of intravitreal conbercept (a recombinant fusion protein that primarily targets vascular endothelial growth factors) after vitrectomy for the management of proliferative diabetic retinopathy without tractional retinal detachment (TRD).

SUBJECTS/METHODS

Fifty patients with non-clearing vitreous haemorrhage (VH) due to proliferative diabetic retinopathy without TRD were enroled. They were randomly divided into control and treatment groups (25 eyes to each group) after they provided informed consent. The treatment group received intravitreal conbercept (10 mg/mL, 0.5 mg) immediately after surgery, while the control group did not. The best corrected visual acuity (BCVA) and the central retinal thickness were measured.

RESULTS

There were no significant between-group differences in baseline characteristics (P > 0.05), except in age (P = 0.003). Improvement in BCVA was significantly greater at 1, 4, 12, and 24 weeks post surgery in the treatment group than it was in the control group (P < 0.001). There were more cases in the control group who developed recurrent VH, but the recurrence rate of VH was not significantly different between the two groups at 12 and 24 weeks post surgery (P = 0.192 and  0.103). Central retinal thickness was lower in the treatment group than in the control group at 1 week (P = 0.012), 4 weeks (P = 0.01), 12 weeks (P = 0.001), and 24 weeks (P = 0.004) post surgery, which were statistically significant.

CONCLUSIONS

An intravitreal injection of conbercept after vitrectomy improved visual acuity and seemed to reduce the recurrence of VH resulting in prompt visual recovery in the PDR patients.

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.

Role of bevacizumab in the prevention of early postoperative haemorrhage after 25-gauge microincision vitrectomy surgery

Objective:

To evaluate the effect of preoperative intravitreal bevacizumab injection on the incidence of postoperative haemorrhage and visual prognosis, in patients undergoing 25-gauge micro incision vitrectomy surgery (MIVS) for diabetic vitreous haemorrhage.

Methods:

One hundred and twenty two eyes of 122 patients of diabetic retinopathy of both genders and aged over 18 years, who presented with non-resolving vitreous haemorrhage were enrolled for this study. All patients received an intravitreal injection of 1.25 mg/0.05 mL bevacizumab (Avastin) which was followed one week later by 25-gauge sutureless micro incision vitrectomy surgery. Main outcomes measured were best corrected visual acuity (BCVA) assessed with logMAR and post-operative vitreous haemorrhage. Follow ups were up to six months post-operatively. IBM SPSS 21 was used for data analysis.

Result:

A total of 122 patients were included; 78 (63.9%) males and 44 (36.1%) females. Mean age at the time of surgery was 51.4 ± 13.66 years. The mean preoperative BCVA was 1.64 ± 0.427 logMAR which improved to 0.57 ± 0.253 logMAR at 12 months post-operatively (p-value < 0.001). Recurrent vitreous haemorrhage was seen in four patients (3.28%).

one1 week before 25-gauge vitrectomy helps to reduce the incidence of early post-vitrectomy haemorrhage in diabetic patients.

Long-term outcomes of sutureless 25-G+ pars-plana vitrectomy for the management of diabetic tractional retinal detachment

PURPOSE

To evaluate the short- and long-term surgical and clinical outcomes in eyes with diabetic tractional retinal detachment (TRD) undergoing 25-G+ pars-plana vitrectomy (PPV).

METHODS

A total of 238 patients were reviewed for inclusion in this study. A retrospective cohort study of 109 eyes of 73 patients operated on for diabetic TRD were included. All eyes received intraocular tamponade of air, sulfur hexafluoride, octofluropropane or silicone oil. All patients were followed up for a minimum period of one year.

RESULTS

The mean age of all patients at surgery was 53.9 years ± 9.2, while the mean duration of diabetes was 18.7 ± 10.4 years. The mean length of follow-up was 923 ± 87 days after surgery (range, 432-1792 days). Thirty-two cases (29.3 %) had an associated rhegmatogenous component. Mean BCVA improved from logarithm minimum angle of resolution (logMAR) 1.17 (20/300) to 0.812 (20/130) (p < 0.05). All eyes underwent intraoperative laser photocoagulation. Primary, single-surgery anatomic reattachment was achieved in 99 eyes (91 %). Final anatomic attachment was achieved in 107 eyes (98 %). There was no statistically significant difference in primary or secondary re-attachment rate in terms of type of tamponade agent used. There were five cases of post-operative hypotony (≤5 mmHg) on postoperative day 1, while 11 eyes had IOP ≥ 30 mmHg. There were no cases of endophthalmitis in our cohort.

CONCLUSIONS

25G+ PPV provides for safe and effective repair of diabetic TRDs. Patients experienced positive functional and anatomic outcomes, with no significant intraoperative complications and minimal postoperative sequelae.

Evaluation of Intravitreal Ranibizumab on the Surgical Outcome for Diabetic Retinopathy With Tractional Retinal Detachment

This study aims to investigate intravitreal injection of Ranibizumab on the surgical outcome for diabetic patients who had tractional retinal detachment but did not receive any preoperative retinal photocoagulation.Ninety-seven patients (97 eyes) who had diabetic retinopathy with tractional retinal detachment were enrolled to receive 23-G pars plana vitrectomy (PPV). They were assigned to an experimental group (Group I, n = 47 eyes) and a control group (Group II, n = 50 eyes). The patients in Group I were given 1 injection of intravitreal Ranibizumab (Lucentis 0.5 mg/0.05 mL) 1 week before surgery, whereas those in Group II went down to surgery directly. Follow-ups were performed for 6 months to 3 years (16 ± 6 months), and indicators observed included postoperative best-corrected visual acuity, complications, and retinal thickness in the macula measured by optical coherence tomography.In Group I, BCVA improved from logMAR 1.92 ± 0.49 to logMAR 0.81 ± 0.39 following surgery, whereas in Group II, BCVA improved from logMAR 1.91 ± 0.49 to logMAR 0.85 ± 0.41. There was significant postoperative gain in vision, but there was no significant difference between the 2 groups at postoperative follow-up visits. The mean duration of vitrectomy in Group I and Group II was (40 ± 7) minutes and (53 ± 9) minutes, respectively, with significant difference. Iatrogenic breaks were noted in 5 eyes (11%) in the experimental group and 17 eyes (34%) in the control group; the difference was significant. The retinal thickness in the macula measured by OCT was (256 ± 44) μm and (299 ± 84) μm in Group I and Group II respectively with significant difference. Besides, there were significantly more eyes in Group II that required silicone oil tamponade and postoperative retinal photocoagulation.23-G PPV combined with intravitreal tamponade and panretinal photocoagulation still remains an effective regimen for the treatment of diabetic retinopathy complicated with tractional retinal detachment. Preoperative intravitreal injection of Ranibizumab could shorten surgical duration, reduce intraoperative complications, and sometimes spare the need for silicone oil tamponade and postoperative retinal photocoagulation, alleviating patients' suffering from surgery.

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.

Changing paradigms of anti-VEGF in the Indian scenario

Anti-vascular endothelial growth factors (VEGF) agents have revolutionized the treatment of retinal diseases. Use of anti-VEGF agents in the Indian Scenario present some unique challenges considering the absence of compounding pharmacies, poor penetrance of health insurance and limited affordability of the citizens of a developing economy. To study the changing paradigms of anti-VEGF use in the Indian scenario, all articles published by Indian authors, data from web-based surveys amongst Indian vitreo-retinal specialists were reviewed. In the paucity of compounding pharmacies in India, fractionation and injection techniques differ from those of developed countries. Frequent anti-VEGF monotherapy offers the best anatomical and visual results, but economics of scale do not allow the same in the Indian scenario, resulting in PRN dosing and combination of anti-VEGF with laser photocoagulation, being the commonly employed treatment protocols.

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.

Outcome of a Single Intravitreal Bevacizumab Injection on the Visual Acuity and Course of Pars Plana Vitrectomy in Proliferative Diabetic Retinopathy

Abstract Purpose: To evaluate the effect of a single intravitreal 1.25 mg/0.05 ml bevacizumab (IVB) (Avastin, Genentech) injection on the visual outcome and both intraoperative and postoperative course of pars plana vitrectomy (PPV) in proliferative diabetic retinopathy. Study Design: Prospective case-control interventional comparative study. Methods: One hundred patients (100 eyes) were divided into two groups: Group I had undergone PPV with preoperactive IVB (50 patients), and Group II had undergone PPV without IVB (50 patients). Best corrected visual acuity (BCVA), intraoperative and postoperative complications were compared between both groups. Patients were followed-up for one year. Results: After one year, there was a highly statistically significant difference in the mean BCVA, as it was (0.146 ± 0.103) in Group I and 0.069 ± 0.049 in Group II with (p < 0.001), while mean bleeding frequency in Group I was 0.7 ± 0.78 times/case with range between 0 and 2 bleeding attacks/case and mean bleeding frequency in Group II was 3.12 ± 1.31times/case with range between 3 and 6 bleeding attacks/case and the difference was statistically significant as (p < 0.001). Diathermy was used in Group I in 15 patients only with mean frequency of 0.3 ± 0.46 times/case with range between 0 and 1 attack/case; while diathermy was used in all cases in Group II with mean frequency of 2.4 ± 1.06 times/case with range between 1 to 4 times/case and this difference was also statistically significant as p < 0.001. Postoperative vitreous hemorrhage developed in 3 eyes (6%) in Group I and 15 eyes (30%) in Group II and this difference was statistically significant (p < 0.003). All the other intraoperative and postoperative complications were reduced in Group I, but with no statistically significant difference between both groups. Conclusions: The use of intravitreal bevacizumab before pars plana vitrectomy is beneficial in improving visual outcome, minimizing the incidence of intraoperative bleeding and reducing the need for intraoperative diathermy.