Efficacy and Safety of Intravitreal Conbercept, Ranibizumab, and Triamcinolone on 23-Gauge Vitrectomy for Patients with Proliferative Diabetic Retinopathy

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.

Comparison of the adjuvant effect of conbercept intravitreal injection at different times before vitrectomy for proliferative diabetic retinopathy

Purpose

To assess the optimal time of intravitreal conbercept (IVC) treatment prior to pars plana vitrectomy (PPV) in patients with severe proliferative diabetic retinopathy (PDR).

Method

This study was exploratory in nature. Forty-eight consecutive patients (48 eyes) with PDR were divided into four groups according to different IVC times (0.5 mg/0.05 mL) before PPV: group A (3 days), group B (7 days), group C (14 days), and group D (non-IVC). Intraoperative and postoperative effectiveness were assessed, and vitreous VEGF concentrations were detected.

Result

For intraoperative effectiveness, groups A and D had a higher incidence of intraoperative bleeding than groups B and C (P = 0.041). Furthermore, groups A-C required less surgical time than group D (P < 0.05). For postoperative effectiveness, group B had a significantly higher proportion of visual acuity that improved or remained unchanged than group D (P = 0.014), and groups A-C had lower proportions of postoperative bleeding than group D. The vitreous VEGF concentration of group B (67.04 ± 47.24 pg/mL) was significantly lower than that of group D (178.29 ± 110.50 pg/mL) (P = 0.005).

Conclusion

IVC treatment that was administered 7 days preoperatively was associated with better effectiveness and a lower vitreous VEGF concentration than its administration at other time points.

Diabetic Retinopathy – Diagnostics and Treatment Guidelines

Diabetic retinopathy is one of the most common complications of diabetes mellitus and represents a serious health, social and economic problem. With the expected increase in the number of patients with diabetes, it is becoming the leading cause of severe vision loss in the working-age population.  The presented guidelines summarize the current knowledge about this disease in order to standardize and update the procedures for the diagnosis, classification and treatment of diabetic retinopathy.

Comparison of efficacy and safety of intravitreal ranibizumab and conbercept before vitrectomy in Chinese proliferative diabetic retinopathy patients: a prospective randomized controlled trial

BACKGROUND

To compare the efficacy and safety of preoperative intravitreal injections of ranibizumab and conbercept in Chinese proliferative diabetic retinopathy (PDR) patients.

METHODS

This prospective randomized controlled trial enrolled 90 eyes of 80 patients with PDR. Forty-four eyes of 40 patients that received intravitreal ranibizumab (IVR) injections (0.5 mg/0.05 mL) before vitreous surgeries were assigned to the IVR group. Forty-six eyes of 40 patients that received intravitreal conbercept (IVC) injections (0.5 mg/0.05 mL) before vitreous surgeries were assigned to the IVC group. Intraoperative and postoperative indices were assessed for further comparison between the two groups.

RESULTS

There were no statistically significant differences in all surgery indices, including intraoperative indices (surgery time, P = 0.225; intraoperative bleeding, P = 0.808; endodiathermy use, P = 0.693; incidence of iatrogenic retinal breaks, P = 0.740; relaxing retinotomy, P = 0.682; retinal reattachment, P = 0.682 and silicone oil tamponade, P = 0.814) and postoperative indices (postoperative vitreous hemorrhage (VH), P = 0.808; neovascular glaucoma (NVG), P = 0.964; recurrent retinal detachment, P = 0.531; postoperative fibrovascular proliferation progression, P = 0.682 and reoperation, P = 0.955) between the two groups. There were no statistically significant differences in best-corrected visual acuity (BCVA) at each follow-up visit (P = 0.939, 0.669, 0.741 and 0.717, respectively) or in central retinal thickness (CRT) (P = 0.976, 0.699, 0.551 and 0.686, respectively). As for safety profile, both groups had no ocular or system adverse events during the observation period.

CONCLUSIONS

IVR and IVC as a pretreatment of vitrectomy had similar efficacy and safety profile for Chinese PDR patients.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov ( NCT05414149 ).

Intravitreal conbercept as an adjuvant in vitrectomy for proliferative diabetic retinopathy: a meta-analysis of randomised controlled trials

PURPOSE

To evaluate the efficacy of intravitreal conbercept (IVC) in pars plana vitrectomy (PPV) for patients with proliferative diabetic retinopathy (PDR).

METHODS

A meta-analysis of randomized control trials (RCTs) using online databases was performed. The intraoperative outcome measures were the incidence of intraoperative bleeding and endodiathermy application, and the mean surgical time. The postoperative outcome measures were mean change in best-corrected visual acuity (BCVA) from baseline, postoperative vitreous clear-up time and incidence of recurrent vitreous hemorrhage (VH).

RESULTS

Eight RCTs were selected for meta-analysis. They included 409 eyes (215 eyes in IVC group and 194 eyes in no conbercept group). Preoperative IVC application was associated with less intraoperative bleeding and endodiathermy applications (RR = 0.34, 95% CI, 0.23-0.50, P < 0.00001, and RR = 0.26, 95% CI, 0.12-0.56, P = 0.0005) compared to no conbercept. It also shortened surgical time (WMD = -15.87, 95% CI, -22.04 to -9.69, P < 0.00001). In addition, preoperative or intraoperative IVC achieved better BCVA outcome (WMD = -0.37, 95% CI, -0.62 to -0.13, P = 0.003), shorter vitreous clear-up time postoperatively (WMD = -5.44, 95% CI, -6.31 to -4.57, P < 0.00001) and a lower rate of VH recurrence (RR = 0.45, 95% CI, 0.22-0.91, P = 0.03).

CONCLUSION

IVC is an effective adjuvant in PPV for PDR, with better intraoperative and postoperative outcomes.

The efficacy and safety of intravitreal injection of Ranibizumab as pre-treatment for vitrectomy in proliferative diabetic retinopathy with vitreous hemorrhage

Background

Intravitreal injection of anti-vascular endothelial growth factor (VEGF) has become first line therapy for diabetic macular edema. This study evaluated the efficacy and safety of intravitreal injection of Ranibizumab (IVR) as pre-treatment for pars plana vitrectomy in proliferative diabetic retinopathy (PDR) patients with vitreous hemorrhage.

Methods

This pilot randomized controlled trial included 48 eyes with vitreous hemorrhage resulting from active PDR. Eyes were treated with IVR 1 or 3 days before vitrectomy or a sham subconjunctival injection 3 days before surgery. The occurrence of new tractional retinal detachment (TRD), total operation time, and intraoperative findings were compared. The concentrations of VEGF and connective tissue growth factor (CTGF) in aqueous humor and plasma collected at the time of IVR and vitrectomy were determined by ELISA.

Results

None of the patients who received IVR experienced new TRD. Ranibizumab injection improved intraoperative outcomes. The mean concentrations of VEGF in aqueous humor were significantly lower after than before IVR in patients who received IVR 1 and 3 days before surgery (P < 0.001 each). The CTGF/log₁₀ (VEGF) ratio was significantly higher after than before IVR in patients who received IVR 3 days before vitrectomy (P = 0.046).

Conclusion

Preoperative IVR is an effective and safe strategy for the surgical treatment of severe PDR combined with vitreous hemorrhage. IVR 1 and 3 days before surgery can significantly reduce VEGF content in aqueous humor and effectively improve intraoperative conditions without causing TRD.

Trial registration

This study was registered with the Chinese Clinical Trial Registry. Name of the registry: Exploratory analysis of effect of intravitreal ranibizumab as pre-treatment for pars plana vitrectomy in proliferative diabetic retinopathy. Trial registration number: ChiCTR-ONC-16009520. Date of registration: October 20, 2016. URL of trial registry record: http://www.chictr.org.cn/searchprojen.aspx

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.

Updates on the Management of Ocular Vasculopathies with VEGF Inhibitor Conbercept

Purpose: To provide a detailed review on the therapeutic efficacy of conbercept for the management of ocular vasculopathies. Methods: A comprehensive literature search of various electronic databases was performed. Results: Ocular vasculopathy is one of the major causes of visual impairment and blindness which includes a range of disorders. Vascular endothelial growth factor (VEGF) regulates angiogenesis, enhances vascular permeability, and drives the formation of neovascularization. Anti-VEGF therapy has been shown to prevent vision loss or potentially improve vision in patients with exudative or neovascular retinal disease. The most recent anti-VEGF drug in China is conbercept. In the USA and Europe, bevacizumab is the most recently approved anti-VEGF agent. Conclusions: Conbercept serves as another anti-VEGF option for patients with neovascular AMD and other retinal vascular disorders. There have not been many clinical trials that study conbercept as compared with other currently available anti-VEGF drugs. There is a need for large-scale, well-designed, randomized clinical trials to ensure its long-term safety and efficacy and to determine if it has any advantages over other anti-VEGF agents.

Intravitreal conbercept improves outcome in patients undergoing vitrectomy for proliferative diabetic retinopathy: A systematic review and meta-analysis

OBJECTIVES

To evaluate the latest evidence concerning the efficacy of conbercept on vitrectomy for proliferative diabetic retinopathy (PDR) and its efficacy compared to control and other antivascular endothelial growth factor.

METHODS

We performed a systematic literature search on topics that assess the role of conbercept in patients undergoing vitrectomy for PDR from inception to November 2019, using PubMed, EuropePMC, Cochrane Central Database, ProQuest, ScienceDirect, and Clinicaltrials.gov. Two researchers independently searched literature, extracted data, and evaluated the risk of bias. RevMan 5.3 and StataMP 16 software were used to perform data analysis.

RESULTS

There were 699 cases (eyes) from eight studies. Baseline best-corrected visual acuity (BCVA) was better in the control group compared to conbercept group (mean difference [MD] = 0.13, I²   = 0%). A greater BCVA improvement was observed in the conbercept group after 1-month (MD = -0.27, I²   = 1%), 3-month (MD = -0.28, I²   = 0%), and 6-month (MD = -0.20, I²   = 78%) follow-up. The need for endodiathermy (odds ratio [OR] = 0.20, I²   = 0%) and silicone oil tamponade use (OR = 0.59, I²   = 72%) and intraoperative bleeding (OR = 0.11, I²   = 33%) was lower in conbercept group. Postoperative early (OR = 0.22, I²   = 0%) and late (OR = 0.47, I²   = 0%) vitreous hemorrhage was lower in conbercept group. There was no significant difference in BCVA improvement and intraoperative outcome between conbercept and ranibizumab.

CONCLUSIONS

Intravitreal conbercept was associated with a more significant BCVA improvement, better intraoperative outcome, and less postoperative vitreous hemorrhage compared to no conbercept.

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.

Longitudinal neovascular changes on optical coherence tomography angiography in proliferative diabetic retinopathy treated with panretinal photocoagulation alone versus with intravitreal conbercept plus panretinal photocoagulation: a pilot study

PURPOSE

To investigate the longitudinal changes in neovascularization of the retinal elsewhere (NVE) size on optical coherence tomography angiography (OCTA) in proliferative diabetic retinopathy (PDR) treated by panretinal photocoagulation (PRP) alone or by single intravitreal conbercept injection plus PRP.

METHODS

A prospective pilot study. Forty-four PDR eyes with NVE confirmed by fundus fluorescein angiography (FFA) and OCTA were included. They were assigned to receive PRP alone (PRP group) or intravitreal conbercept injection plus PRP (combination group). Ophthalmic examinations, including BCVA and OCTA to measure the NVE size, were performed at baseline before each PRP session, and at 1, 3, and 6 months.

RESULTS

Twenty-nine eyes were included in the PRP group, and 15 eyes were included in the combination group. There was no significant difference between the two groups with respect to age, BCVA, and NVE area at baseline. In both groups, there was a significant (P < 0.05) NVE size reduction during the majority of study visits, with the reduction observed in the combination group significantly larger than that in the PRP group. No significant BCVA changes were observed in either groups, except that in the PRP group, the BCVA at 3 months was significantly improved (P < 0.05). No deaths or unexpected adverse events (AEs) were reported.

CONCLUSIONS

Intravitreal conbercept plus PRP was more effective than PRP monotherapy in NVE regression. Precise quantification of the NVE area by OCTA makes it a useful tool for monitoring the response of retinal neovascular lesions to the therapy.

Preoperative Intravitreal Conbercept Facilitates Vitrectomy in Proliferative Diabetic Retinopathy: Is Attention Required for the Fellow Eye?

Purpose

To evaluate the effect of preoperative intravitreal conbercept (IVC) injection on patients with proliferative diabetic retinopathy (PDR).

Methods

Medical records of patients who underwent vitrectomy due to complications of PDR were retrospectively reviewed. Patients were grouped as the IVC group and non-IVC group according to preoperative IVC. Preoperative, intraoperative, and postoperative data of both eyes were collected. The main outcome measures were best-corrected visual acuity (BCVA), intraocular pressure (IOP), central retinal thickness (CRT), and incidence of tractional retinal detachment (TRD).

Results

A total of 37 cases were included, 16 in the IVC group and 21 in the non-IVC group. Preoperative IVC significantly reduced surgical duration (IVC vs. non-IVC, 88.9 ± 11.9 min vs. 97.8 ± 12.8 min, p  <  0.05). In the vitrectomized eye, no significant difference existed between the IVC group and non-IVC group regarding postoperative BCVA (logMAR, 1.20 ± 0.53 vs. 1.27 ± 0.54, p = 0.68), IOP (16.5 ± 2.9 mmHg vs. 15.6 ± 3.7 mmHg, p = 0.44), and CRT (330.1 ± 35.2 μm vs. 319.2 ± 32.5 μm, p=0.34). In the fellow eye, 6 cases in the IVC group were diagnosed with TRD during postoperative follow-up, while only 2 cases were diagnosed in the non-IVC group (p  <  0.05).

Conclusion

Preoperative intravitreal injection of conbercept has effectively facilitated vitrectomy in PDR patients, but it potentially promotes tractional retinal detachment in the fellow eye following preoperative injection.