Ranibizumab pretreatment in diabetic vitrectomy: a pilot randomised controlled trial (the RaDiVit study)

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.

Anti-vascular endothelial growth factor for proliferative diabetic retinopathy

BACKGROUND

Proliferative diabetic retinopathy (PDR) is an advanced complication of diabetic retinopathy that can cause blindness. It consists of the presence of new vessels in the retina and vitreous haemorrhage. Although panretinal photocoagulation (PRP) is the treatment of choice for PDR, it has secondary effects that can affect vision. Anti-vascular endothelial growth factor (anti-VEGF), which produces an inhibition of vascular proliferation, could improve the vision of people with PDR.

OBJECTIVES

To assess the effectiveness and safety of anti-VEGFs for PDR and summarise any relevant economic evaluations of their use.

SEARCH METHODS

We searched 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. We did not use any date or language restrictions. We last searched the electronic databases on 1 June 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing anti-VEGFs to another active treatment, sham treatment, or no treatment for people with PDR. We also included studies that assessed the combination of anti-VEGFs with other treatments. We excluded studies that used anti-VEGFs in people undergoing vitrectomy.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted data, and assessed the risk of bias (RoB) for all included trials. We calculated the risk ratio (RR) or the mean difference (MD), and 95% confidence intervals (CI). We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 15 new studies in this update, bringing the total to 23 RCTs with 1755 participants (2334 eyes). Forty-five per cent of participants were women and 55% were men, with a mean age of 56 years (range 48 to 77 years). The mean glycosylated haemoglobin (Hb1Ac) was 8.45% for the PRP group and 8.25% for people receiving anti-VEGFs alone or in combination. Twelve studies included people with PDR, and participants in 11 studies had high-risk PDR (HRPDR). Twelve studies were of bevacizumab, seven of ranibizumab, one of conbercept, two of pegaptanib, and one of aflibercept. The mean number of participants per RCT was 76 (ranging from 15 to 305). Most studies had an unclear or high RoB, mainly in the blinding of interventions and outcome assessors. A few studies had selective reporting and attrition bias. No study reported loss or gain of 3 or more lines of visual acuity (VA) at 12 months. Anti-VEGFs ± PRP probably increase VA compared with PRP alone (mean difference (MD) -0.08 logMAR, 95% CI -0.12 to -0.04; I2 = 28%; 10 RCTS, 1172 eyes; moderate-certainty evidence). Anti-VEGFs ± PRP may increase regression of new vessels (MD -4.14 mm2, 95% CI -6.84 to -1.43; I2 = 75%; 4 RCTS, 189 eyes; low-certainty evidence) and probably increase a complete regression of new vessels (RR 1.63, 95% CI 1.19 to 2.24; I2 = 46%; 5 RCTS, 405 eyes; moderate-certainty evidence). Anti-VEGFs ± PRP probably reduce vitreous haemorrhage (RR 0.72, 95% CI 0.57 to 0.90; I2 = 0%; 6 RCTS, 1008 eyes; moderate-certainty evidence). Anti-VEGFs ± PRP may reduce the need for vitrectomy compared with eyes that received PRP alone (RR 0.67, 95% CI 0.49 to 0.93; I2 = 43%; 8 RCTs, 1248 eyes; low-certainty evidence). Anti-VEGFs ± PRP may result in little to no difference in the quality of life compared with PRP alone (MD 0.62, 95% CI -3.99 to 5.23; I2 = 0%; 2 RCTs, 382 participants; low-certainty evidence). We do not know if anti-VEGFs ± PRP compared with PRP alone had an impact on adverse events (very low-certainty evidence). We did not find differences in visual acuity in subgroup analyses comparing the type of anti-VEGFs, the severity of the disease (PDR versus HRPDR), time to follow-up (< 12 months versus 12 or more months), and treatment with anti-VEGFs + PRP versus anti-VEGFs alone. The main reasons for downgrading the certainty of evidence included a high RoB, imprecision, and inconsistency of effect estimates.

AUTHORS' CONCLUSIONS

Anti-VEGFs ± PRP compared with PRP alone probably increase visual acuity, but the degree of improvement is not clinically meaningful. Regarding secondary outcomes, anti-VEGFs ± PRP produce a regression of new vessels, reduce vitreous haemorrhage, and may reduce the need for vitrectomy compared with eyes that received PRP alone. We do not know if anti-VEGFs ± PRP have an impact on the incidence of adverse events and they may have little or no effect on patients' quality of life. Carefully designed and conducted clinical trials are required, assessing the optimal schedule of anti-VEGFs alone compared with PRP, and with a longer follow-up.

Prospective Comparison of Surgery Outcome Between Preoperative and Intraoperative Intravitreal Injection of Ranibizumab for Vitrectomy in Proliferative Diabetic Retinopathy Patients

INTRODUCTION

To compare the efficacy and safety of intravitreal injections of ranibizumab (IVR) before and at the end of vitrectomy in proliferative diabetic retinopathy (PDR) patients.

METHODS

A prospective comparative study was performed on 60 eyes of 52 PDR patients who received ranibizumab injection (0.5 mg/0.05 ml) 3-5 days before vitrectomy (preoperative group) and 55 eyes of 50 PDR patients who received ranibizumab injection (0.5 mg/0.05 ml) at the end of vitrectomy (intraoperative group). Intra- and postoperative indices were collected for further comparison.

RESULTS

Postoperative best-corrected visual acuity (BCVA) in preoperative group was better than in intraoperative group at 1 week after surgery (P < 0.05) but comparable at 1- and 3-month follow-up (P = 0.20 and P = 0.37, respectively). Central retinal thickness (CRT) in preoperative group was lower than in intraoperative group at 1 week postoperatively (P < 0.05), but comparable at 1- and 3-month follow-up (P = 0.39 and P = 0.77, respectively). The average surgery time was significantly shorter in preoperative group than in intraoperative group (61.50 ± 11.44 min vs. 74.49 ± 12.01 min, P < 0.01). The incidence of intraoperative bleeding was significant lower in preoperative group than in intraoperative group (21.7% vs. 40.0%, P < 0.05). Moreover, the incidence of intraocular electrocoagulation use, iatrogenic retinal breaks, relaxing retinotomy and silicone oil tamponade were all significantly lower in preoperative group than that in intraoperative group (P < 0.05, respectively). The incidences of postoperative vitreous hemorrhage (VH), neovascular glaucoma (NVG), recurrent retinal detachment, postoperative fibrovascular proliferation progression and reoperation showed no statistical differences between the two groups (P > 0.05, respectively). Both groups had no ocular or system adverse events during observation period.

CONCLUSION

In vitrectomy for PDR, preoperative IVR can significantly reduce surgery time and lower the incidence of intraoperative bleeding, intraocular electrocoagulation use, iatrogenic retinal breaks, relaxing retinotomy and silicone oil tamponade during surgery and gain short-term better postoperative BCVA and thinner CRT.

TRIAL REGISTRATION

ClinicalTrials.gov (identifier, NCT05408416).

Intravitreal Anti-Vascular Endothelial Growth Factor Agents for the Treatment of Diabetic Retinopathy: A Review of the Literature

Background: Diabetic retinopathy (DR) is the leading cause of blindness in the working-age population. The purpose of this review is to gather the existing literature regarding the use of the approved anti-vascular endothelial growth (anti-VEGF) agents in the treatment of DR. Methods: A comprehensive literature review in PubMed engine search was performed for articles written in English language up to 1 July 2021, using the keywords “diabetic retinopathy”, “ranibizumab”, “aflibercept”, and “anti-VEGF”. Emphasis was given on pivotal trials and recent robust studies. Results: Intravitreal anti-VEGF agents have been found to significantly improve visual acuity and reduce retinal thickness in patients with diabetic macular edema (DME) in a long-term follow-up ranging from 1 to 5 years and are considered the standard-of-care in such patients. Regarding DR, intravitreal anti-VEGF agents provided ≥2-step improvement in DR severity on color fundus photography in about 30–35% of patients with NPDR at baseline, in the majority of clinical trials originally designed to evaluate the efficacy of intravitreal anti-VEGF agents in patients with DME. Protocol S and CLARITY study have firstly reported that intravitreal anti-VEGF agents are non-inferior to panretinal photocoagulation (PRP) in patients with proliferative DR (PDR). However, the use of new imaging modalities, such as optical coherence tomography-angiography and wide-field fluorescein angiography, reveals conflicting results about the impact of anti-VEGF agents on the regression of retinal non-perfusion in patients with DR. Furthermore, one should consider the high “loss to follow-up” rate and its devastating consequences especially in patients with PDR, when deciding to treat the latter with intravitreal anti-VEGF agents alone compared to PRP. In patients with PDR, combination of treatment of intravitreal anti-VEGF agents and PRP has been also supported. Moreover, in the specific case of vitreous hemorrhage or tractional retinal detachment as complications of PDR, intravitreal anti-VEGF agents have been found to be beneficial as an adjunct to pars plana vitrectomy (PPV), most commonly given 3–7 days before PPV, offering reduction in the recurrence of vitreous hemorrhage. Conclusions: There is no general consensus regarding the use of intravitreal anti-VEGF agents in patients with DR. Although anti-VEGF agents are the gold standard in the treatment of DME and seem to improve DR severity, challenges in their use exist and should be taken into account in the decision of treatment, based on an individualized approach.

Anti-VEGF crunch syndrome in proliferative diabetic retinopathy: A review

Anti-vascular endothelial growth factor (anti-VEGF) crunch syndrome describes the progression to tractional retinal detachment following intravitreal anti-VEGF therapy in an eye with proliferative diabetic retinopathy . We reviewed the literature on the anti-VEGF crunch using the PubMed and Cochrane databases. Anti-VEGF crunch typically manifests as sudden vision loss in the affected eye between 1 and 6 weeks following intravitreal anti-VEGF injection, with a mean onset of 13 days. Risk factors for crunch development include the use of a higher anti-VEGF dose and increased severity of diabetic retinopathy with fibrosis. Our review found that intravitreal anti-VEGF, in particular bevacizumab, should be used with caution when treating patients with severe proliferative diabetic retinopathy and pre-existing intraocular fibrosis. In patients where anti-VEGF is used before a planned vitrectomy, we recommend close monitoring for crunch symptoms and proceeding promptly with surgery if there is new or progression of tractional retinal detachment. For eyes with minimal preexisting traction that develop crunch after anti-VEGF treatment, surgeons should proceed to vitrectomy within 7 days. The existing literature on the anti-VEGF crunch is limited by heterogeneity in the way crunch is documented and characterized and the presence of panretinal photocoagulation as a confounding factor. Because of these methodological flaws, the relative frequency of the anti-VEGF crunch cannot be accurately estimated.

Analysis of the etiologies, treatments and prognoses in children and adolescent vitreous hemorrhage

AIM

To determine the etiologies, treatment modalities and visual outcomes of vitreous hemorrhage (VH; range from birth to 18y).

METHODS

A total of 262 eyes from 210 patients between January 2010 and September 2016 were included. All children underwent an appropriate ocular and systemic examination. Data collected included demographics, clinical manifestations, details of the ocular and systemic examination, management details, final fundus anatomy and visual acuity (VA).

RESULTS

The most common etiologies were non-traumatic VH (64.89%), most of which were due to retinopathy of prematurity (ROP; 37.10%); while traffic accidents, including 16 (21.00%) eyes, was the most common ocular traumas. Surgery, performed in 143 (54.58%) eyes, was the most common management modality. The initial mean baseline visual acuity was 2.77±0.21 logarithm of the minimal angle of resolution (logMAR) in children and adolescent with traumatic VH, which was significantly improved to 2.15±1.31 logMAR (P<0.05).

CONCLUSION

VH in children and adolescent has a complicated and diverse etiology. ROP is the primary cause of non-traumatic VH, which is the most common etiology. Appropriate treatment of traumatic VH is associated with obvious improvement in visual acuity. The initial VA is one of most important predictors of outcome.

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.

The Evolving Treatment of Diabetic Retinopathy

Purpose

To review the current therapeutic options for the management of diabetic retinopathy (DR) and diabetic macular edema (DME) and examine the evidence for integration of laser and pharmacotherapy.

Methods

A review of the PubMed database was performed using the search terms diabetic retinopathy, diabetic macular edema, neovascularization, laser photocoagulation, intravitreal injection, vascular endothelial growth factor (VEGF), vitrectomy, pars plana vitreous surgery, antiangiogenic therapy. With additional cross-referencing, this yielded 835 publications of which 301 were selected based on content and relevance.

Results

Many recent studies have evaluated the pharmacological, laser and surgical therapeutic strategies for the treatment and prevention of DR and DME. Several newer diagnostic systems such as optical coherence tomography (OCT), microperimetry, and multifocal electroretinography (mfERG) are also assisting in further refinements in the staging and classification of DR and DME. Pharmacological therapies for both DR and DME include both systemic and ocular agents. Systemic agents that promote intensive glycemic control, control of dyslipidemia and antagonists of the renin-angiotensin system demonstrate beneficial effects for both DR and DME. Ocular therapies include anti-VEGF agents, corticosteroids and nonsteroidal anti-inflammatory drugs. Laser therapy, both as panretinal and focal or grid applications continue to be employed in management of DR and DME. Refinements in laser devices have yielded more tissue-sparing (subthreshold) modes in which many of the benefits of conventional continuous wave (CW) lasers can be obtained without the adverse side effects. Recent attempts to lessen the burden of anti-VEGF injections by integrating laser therapy have met with mixed results. Increasingly, vitreoretinal surgical techniques are employed for less advanced stages of DR and DME. The development and use of smaller gauge instrumentation and advanced anesthesia agents have been associated with a trend toward earlier surgical intervention for diabetic retinopathy. Several novel drug delivery strategies are currently being examined with the goal of decreasing the therapeutic burden of monthly intravitreal injections. These fall into one of the five categories: non-biodegradable polymeric drug delivery systems, biodegradable polymeric drug delivery systems, nanoparticle-based drug delivery systems, ocular injection devices and with sustained release refillable devices. At present, there remains no one single strategy for the management of the particular stages of DR and DME as there are many options that have not been rigorously tested through large, randomized, controlled clinical trials.

Conclusion

Pharmacotherapy, both ocular and systemic, will be the primary mode of intervention in the management of DR and DME in many cases when cost and treatment burden are less constrained. Conventional laser therapy has become a secondary intervention in these instances, but remains a first-line option when cost and treatment burden are more constrained. Results with subthreshold laser appear promising but will require more rigorous study to establish its role as adjunctive therapy. Evidence to support an optimal integration of the various treatment options is lacking. Central to the widespread adoption of any therapeutic regimen for DR and DME is substantiation of safety, efficacy, and cost-effectiveness by a body of sound clinical trials.

Incidence and Risk Factors for Tractional Macular Detachment after Anti-Vascular Endothelial Growth Factor Agent Pretreatment before Vitrectomy for Complicated Proliferative Diabetic Retinopathy

The study’s purpose was to determine the incidence, risk factors, and outcomes of tractional macular detachment after anti-vascular endothelial growth factor (VEGF) pretreatment before vitrectomy for complicated proliferative diabetic retinopathy. Patients who underwent primary vitrectomy for complicated proliferative diabetic retinopathy, from January 2012 to 31 December 2018, were enrolled. Ophthalmic and pre-operative data were extracted from electronic record systems. All eyes with a valuable Optical Coherence Tomography (OCT)performed within 5 days before injection of anti-VEGF and on the day of vitrectomy were included. Multivariable logistic regression showed that significant risk factors for developing tractional macular detachment included days between anti-VEGF and vitrectomy (OR, 0.71 [95% CI 0.65–0.76]; p < 0.001), vitreous hemorrhage (OR, 0.23 [95% CI 0.11–0.49]; p < 0.001), and age (OR, 1.05 [95% CI 1.02–1.08]; p < 0.001). Decision-tree analysis showed that the stronger predictors of tractional macular detachment were the time between anti-VEGF injection and vitrectomy (p < 0.001). Secondary predictors were the presence of vitreous hemorrhage (p = 0.012) in eyes that underwent vitrectomy between 6 and 10 days after anti-VEGF injection and younger age (p = 0.031) in eyes that underwent vitrectomy 10 days after anti-VEGF injection. Tractional macular detachment occurs in 10% of eyes after anti-VEGF injection, the main risk factors being days between anti-VEGF injection and vitrectomy, vitreous hemorrhage, and age.

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.

Efficacy comparison of intravitreal injections of conbercept and ranibizumab for severe proliferative diabetic retinopathy

OBJECTIVE

To determine the efficacy of preoperative intravitreal injections of conbercept (IVC) and ranibizumab (IVR) on postoperative best-corrected visual acuity (BCVA), vitreous hemorrhage (VH), and neovascular glaucoma (NVG) in a population with proliferative diabetic retinopathy (PDR) undergoing vitrectomy.

DESIGN

Retrospective, cross-sectional study.

PARTICIPANTS

386 patients with severe PDR (428 eyes).

METHODS

The patients who did not receive IVC or IVR were assigned to group A (125 eyes), the patients who received IVR (0.5 mg) were assigned to group B (146 eyes), and the patients who received IVC (0.5 mg) were assigned to group C (157 eyes).

RESULTS

Both group B (p = 0.009) and group C (p = 0.002) had better postoperative BCVA than group A. Early postoperative VH occurred significantly less frequently in group B (22.60%; p = 0.007) and group C (12.10%; p < 0.001) than in group A (37.60%). Importantly, the incidences of postoperative NVG in group B (2.74%; p = 0.001) and group C (0.64%; p < 0.001) were both significantly less than that in group A (15.20%). However, there was no significant difference in the incidences of postoperative NVG between groups B and C (p = 0.325).

CONCLUSIONS

The contribution of preoperative IVC to an improved BCVA for patients with severe PDR was better than that of IVR, and IVC decreased the risk of postoperative early VH. Pretreatment with IVC or IVR reduced the incidence of postoperative NVG based on the 24-month follow-up data.

Antivascular endothelial growth factor agents pretreatment before vitrectomy for complicated proliferative diabetic retinopathy: a meta-analysis of randomised controlled trials

Background/aims

To evaluate the efficacy of antivascular endothelial growth factor (anti-VEGF) agents pretreatment before vitrectomy for patients with complicated proliferative diabetic retinopathy (PDR).

Methods

The PubMed, Embase and the Cochrane Central Register of Controlled Trials were searched up to June 2017 to identify related studies. The Peferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed. The StataSE V.12.0 software was used to analyse the relevant data. The weighted mean difference, relative risk and their 95% CIs were used to assess the strength of the association.

Results

14 randomised controlled trials involving 613 patients were assessed, the anti-VEGF pretreatment group included 289 patients and the control group included 324 patients. Our analysis indicated that anti-VEGF pretreatment before vitrectomy for complicated PDR could facilitate much easier surgery regarding less intraoperative bleeding, less endodiathermy, shorter duration of surgery, less iatrogenic retinal breaks, less frequency of using silicone oil and relaxing retinotomy (P<0.05). Additionally, anti-VEGF pretreatment could also achieve better postoperative best-corrected visual acuity, less early recurrent vitreous haemorrhage (VH) and quicker absorption of recurrent VH (P<0.05). However, the incidence of late recurrent VH, recurrent retinal detachment or related secondary surgery could not be reduced (P>0.05).

Conclusion

The pretreatment of anti-VEGF agents before vitrectomy for patients with complicated PDR might facilitate much easier surgery and better visual rehabilitation, reduce the rate of early recurrent VH and accelerate its absorption. Moreover, future better-designed studies with larger sample sizes are required to further evaluate the efficacy of different anti-VEGF agents and reach a firmer conclusion.