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.

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.

Corneal Subbasal Nerve Density and Sensitivity After Pars Plana Vitrectomy Using Contact or Noncontact Wide-Angle Viewing Systems

PURPOSE

To assess corneal subbasal nerve density (SBND) and corneal sensitivity (CS) after pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD) without intraoperative 360-degree laser treatment using contact or noncontact panoramic viewing systems.

METHODS

This is a prospective study of 34 eyes affected by RRD, which underwent PPV using contact (18 eyes) and noncontact (16 eyes) panoramic viewing systems; 12 eyes which underwent scleral buckling, and 17 eyes which underwent cataract surgery. SBND and CS were assessed before surgery and 3 and 6 months postoperatively by in vivo confocal microscopy and Cochet-Bonnet esthesiometry.

RESULTS

Compared with baseline values, at 6 months, SBND and CS decreased in both contact PPV (SBND preoperative value: 19.1 ± 3.7 mm/mm; SBND postoperative value: 3.5 ± 1.3 mm/mm; CS preoperative value: 5.1 ± 0.5 cm; CS postoperative value: 1.5 ± 0.4 cm) and in noncontact PPV groups (SBND preoperative value: 19.5 ± 3.8 mm/mm; SBND postoperative value: 8.7 ± 2.3 mm/mm; CS preoperative value: 5.3 ± 0.5 cm; CS postoperative value: 2.5 ± 0.7 cm) (P < 0.001 for all comparisons). SBND reduction was greater in the contact PPV group than in the noncontact PPV group (P < 0.001). By contrast, the scleral buckling and cataract surgery group values were unchanged (P > 0.1 for all comparisons). In multivariate analysis, no significant effect was found for cataract surgery associated with PPV, pseudophakia, surgical time, intraocular pressure, or for laser in horizontal sectors for PPV groups. SBND was highly correlated with CS (r = 0.93).

CONCLUSIONS

A contact viewing system reduces SBND after PPV more than a noncontact system does.

Postoperative Complications of Pars Plana Vitrectomy for Diabetic Retinal Disease

Despite recent advances in the medical management of diabetic retinal disease, there remain established indications for vitreoretinal surgery in the treatment of severe proliferative diabetic retinopathy. These include non-clearing vitreous hemorrhage and tractional retinal detachment. Advances in surgical instrumentation, technique, and experience have led to improved visual outcomes, as well as a corresponding decrease in the incidence of postoperative complications. However, the presence of systemic and ocular factors in diabetic patients increases the risk of adverse events compared to non-diabetic individuals. This review will focus on the most important postoperative complications following pars plana vitrectomy, with specific considerations for the diabetic patient.

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.

Impact of intraoperative topical hydroxypropyl methylcellulose 2% versus sodium hyaluronate 1.2% on corneal reepithelialization after intentional epithelial debridement during vitrectomy

PURPOSE

The aim of this study was to assess the impact of the intraoperative use of topical hydroxypropyl methylcellulose (HPMC) 2% versus sodium hyaluronate 1.2% on corneal reepithelialization time and final corneal status after intentional epithelial debridement during vitrectomy for proliferative vitreoretinopathy.

METHODS

Forty eyes of 40 patients were included in the study, divided into 2 groups of 20 eyes. HPMC 2% and sodium hyaluronate 1.2% were used as corneal protectors in the first and second group, respectively. Patients' charts were reviewed to determine any differences between the HPMC 2% and sodium hyaluronate 1.2% groups in relation to the preoperative, intraoperative, and postoperative factors that could impact postoperative corneal reepithelialization. Postoperative reepithelialization time and final corneal status were recorded.

RESULTS

No significant between-group differences in preoperative, intraoperative, and postoperative factors were found. Reepithelialization time was significantly shorter in the sodium hyaluronate 1.2% group than in the HPMC 2% group, although reepithelialization was eventually achieved in every patient in both groups. Corneal sequelae were significantly more frequent in the HPMC 2% group than in the sodium hyaluronate 1.2% group.

CONCLUSIONS

The choice of the ophthalmic viscosurgical device for intraoperative corneal protection may significantly influence the postoperative corneal status after complicated retinal detachment.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Surgery for diabetic retinopathy

Surgery for diabetic retinopathy addresses late secondary complications of a primary microvascular disease. Since surgery is not a causative therapy, the functional outcome of surgery depends on the degree of retinal ischemia and may be disappointing even in technically and anatomically successfully operated eyes. Typical indications for vitrectomy are vitreous hemorrhage, tractional retinal detachment, combined tractional rhegmatogenous retinal detachment and tractive macular edema. More recently diffuse diabetic macular edema has been shown to improve after removal of an attached vitreous in several cases. Neovascular glaucoma requires aggressive surgical intervention to salvage the eye. Cataract surgery is commonly performed in eyes with diabetic retinopathy. It may however deteriorate diabetic eye disease. Vitreous surgery also has a potential for severe complications in diabetic eyes which can be ameliorated but not eliminated by proper surgical strategies and techniques. The decision for an intervention in diabetic eyes always requires a careful weighing of risks and benefits of surgery.

Visual outcome and risk factors for light perception and no light perception vision after vitrectomy for diabetic retinopathy

PURPOSE

To assess the visual outcome following vitrectomy for diabetic retinopathy compared with previous studies; to evaluate risk factors for light perception (LP) and no light perception (NLP) vision after diabetic vitrectomy.

DESIGN

Retrospective medical record review.

METHODS

The charts of 100 consecutive patients who underwent vitrectomy for proliferative diabetic retinopathy between November 1, 1997, and November 30, 1998, were reviewed. Surgical technique included standard pars plana vitrectomy with combination of delamination and segmentation of gliotic tractional membranes using bimanual techniques. All patients had post-operative follow-up of at least 12 months. Several factors were analyzed for their effect on poor visual outcome (LP and NLP) using Fisher's exact test.

RESULTS

Post-vitrectomy, 73% of diabetic patients had stable or improved vision; 16% had worsened but functional vision, defined as worse but still >or= 20/400; 4% had worsened but ambulatory vision, defined as worse but still count fingers (CF) or hand motion (HM); and 7% had poor visual outcome, LP or NLP. Resultant visual acuity was >or=20/40 in 38% of patients, 20/50 to 20/100 in 34%, 20/120 to CF in 18%, HM in 3%, LP in 4%, and NLP in 3%. Risk factors for eyes with LP and NLP vision included pre-operative iris neovascularization (INV), P = .05, post-operative INV, P = .02, post-operative macular ischemia, P = .0001, and post-operative vitreous hemorrhage (VH), P = .02.

CONCLUSIONS

Pre-operative and post-operative INV, post-operative macular ischemia, and post-operative VH appear to be risk factors for LP and NLP vision following diabetic vitrectomy, whereas overall improvements in surgical technique and visual outcome continue to be reported.