Effect of tranexamic acid on early postvitrectomy diabetic haemorrhage; a randomised clinical trial

Effects of Preoperative Intravenous Versus Subcutaneous Tranexamic Acid on Postoperative Periorbital Ecchymosis and Edema Following Upper Eyelid Blepharoplasty: A Prospective, Randomized, Double-Blinded, Placebo-Controlled, Comparative Study

PURPOSE

To compare the effects of preoperative tranexamic acid (TXA) administered intravenously (IV) versus subcutaneously on postoperative ecchymosis and edema in patients undergoing bilateral upper eyelid blepharoplasty.

METHODS

A prospective, double-blinded, placebo-controlled study of patients undergoing bilateral upper eyelid blepharoplasty at a single-center. Eligible participants were randomized to preoperatively receive either (1) 1 g of TXA in 100 ml normal saline IV, (2) 50 µl/ml of TXA in local anesthesia, or (3) no TXA. Primary outcomes included ecchymosis and edema at postoperative day 1 (POD1) and 7 (POD7). Secondary outcomes included operative time, pain, time until resuming activities of daily living, patient satisfaction, and adverse events.

RESULTS

By comparison (IV TXA vs. local subcutaneous TXA vs. no TXA), ecchymosis scores were significantly lower on POD1 (1.31 vs. 1.56 vs. 2.09, p = 0.02) and on POD7 (0.51 vs. 0.66 vs. 0.98, p = 0.04) among those that received TXA. By comparison (IV TXA vs. local subcutaneous TXA vs. no TXA), significant reductions in edema scores occurred in those that received TXA on POD1 (1.59 vs. 1.43 vs. 1.91, p = 0.005) and on POD7 (0.85 vs. 0.60 vs. 0.99, p = 0.04). By comparison (IV TXA vs. local subcutaneous TXA vs. no TXA) patients treated with intravenous and local subcutaneous TXA preoperatively were more likely to experience shorter operative times (10.8 vs. 11.8 vs. 12.9 minutes, p = 0.01), reduced time to resuming activities of daily livings (1.6 vs. 1.6 vs. 2.3 days, p < 0.0001), and higher satisfaction scores at POD1 (8.8 vs. 8.7 vs. 7.9, p = 0.0002). No adverse events occurred were reported.

CONCLUSION

In an analysis of 106 patients, preoperative TXA administered either IV or subcutaneously safely reduced postoperative ecchymosis and edema in patients undergoing upper eyelid blepharoplasty. While statistical superiority between intravenous versus local subcutaneous TXA treatment was not definitively identified, our results suggest clinical superiority with IV dosing.

Oral tranexamic acid for acute management of active bleeding from iris microhemangiomatosis: A case report

Purpose

to report a case of active intraocular bleeding caused by iris microhemangiomatosis managed with oral tranexamic acid.

Observations

an 80-year-old male was referred to our emergency department for acute intraocular bleeding. Eye exam showed filiform bleeding arising from a cluster of vascular tufts at the upper pupillary margin, which was consistent with a diagnosis of iris microhemangiomatosis. The bleeding had started 6 hours before and could not be halted by conservative maneuvers such as ocular compression and application of sympathomimetic drops. Oral tranexamic acid 500 mg was administered and led to prompt resolution of the hemorrhage within 60 minutes. The patient was monitored for 3 months and showed no recurrence of the hemorrhage.

Conclusion and importance

oral tranexamic acid may represent a viable option to manage active intraocular bleeding from iris microhemangiomatosis, facilitating rapid hemorrhage resolution.

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.

A pilot study of viscoelastic agent to prevent recurrent vitreous hemorrhage after vitrectomy for proliferative diabetic retinopathy

BACKGROUND

To evaluate the possibilty of preventing recurrent vitreous hemorrhage (RVH) after vitrectomy in proliferative diabetic retinopathy (PDR) patients with unabsorbed vitreous hemorrhage (VH) by intravitreal injection of viscoelastic agent (VA) at the end of the surgery and compared its effect with triamcinolone acetonide (TA).

METHODS

This was a pilot prospective, observational study. PDR patients with VH who underwent vitrectomy were assigned to 3 groups according to the tamponade applicated at the end of the surgery, including VA group (intravitreally injected 1 ml VA if the retina was prone to bleed during the operation), TA group (intravitreally injected 2 mg TA when there was much exudates), or balanced salt solution (BSS) group (no tamponade). Then postoperative follow-up was performed routinely until 6 months after surgery. The primary outcome was the incidence of RVH, secondary outcome were the best-corrected visual acuity (BCVA) and introcular pressure (IOP). Cataract formation and other complication were also assessed.

RESULTS

A total of 68 eyes, from 68 patients, were included. 18,18,32 eyes were enrolled in the VA group, TA group and BSS group, respectively. The integral incidence of RVH after vitrectomy was 5.6%, 5.6% and 12.5% respectively (P = 0.602). There was no early RVH in VA or TA group, whereas 3 early RVHs were identified in BSS group, however there was no significant difference (P = 0.171). Every group had one late RVH case. In all groups, final BCVA showed significant improvement compared to baseline. BCVA at any postoperative visit showed no significant differences among 3 groups. Mean IOP was higher 1 week after surgery in VA group compared with the other groups; however, in other times the differences were not significant. No cataract formation and other complication was noted in 3 groups.

CONCLUSION

Intravitreal injection of VA or TA at the end of vitrectomy for PDR patients with unabsorbed VH tend to reduce the incidence of early RVH after vitrectomy similarly. As VA was preferred to applicate in the eyes that were prone to bleed, intravitreal injection of VA at the end of vitrectomy might be a promising method for preventing RVH in PDR patients.

Association of Intravenous Tranexamic Acid With Thromboembolic Events and Mortality: A Systematic Review, Meta-analysis, and Meta-regression

IMPORTANCE

Tranexamic acid (TXA) is an efficient antifibrinolytic agent; however, concerns remain about the potential adverse effects, particularly vascular occlusive events, that may be associated with its use.

OBJECTIVE

To examine the association between intravenous TXA and total thromboembolic events (TEs) and mortality in patients of all ages and of any medical disciplines.

DATA SOURCE

Cochrane Central Register of Controlled Trials and MEDLINE were searched for eligible studies investigating intravenous TXA and postinterventional outcome published between 1976 and 2020.

STUDY SELECTION

Randomized clinical trials comparing intravenous TXA with placebo/no treatment. The electronic database search yielded a total of 782 studies, and 381 were considered for full-text review. Included studies were published in English, German, French, and Spanish. Studies with only oral or topical tranexamic administration were excluded.

DATA EXTRACTION AND SYNTHESIS

Meta-analysis, subgroup and sensitivity analysis, and meta-regression were performed. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

MAIN OUTCOMES AND MEASURES

Vascular occlusive events and mortality.

RESULTS

A total of 216 eligible trials including 125 550 patients were analyzed. Total TEs were found in 1020 (2.1%) in the group receiving TXA and 900 (2.0%) in the control group. This study found no association between TXA and risk for total TEs (risk difference = 0.001; 95% CI, -0.001 to 0.002; P = .49) for venous thrombosis, pulmonary embolism, venous TEs, myocardial infarction or ischemia, and cerebral infarction or ischemia. Sensitivity analysis using the risk ratio as an effect measure with (risk ratio = 1.02; 95% CI, 0.94-1.11; P = .56) and without (risk ratio = 1.03; 95% CI, 0.95-1.12; P = .52) studies with double-zero events revealed robust effect size estimates. Sensitivity analysis with studies judged at low risk for selection bias showed similar results. Administration of TXA was associated with a significant reduction in overall mortality and bleeding mortality but not with nonbleeding mortality. In addition, an increased risk for vascular occlusive events was not found in studies including patients with a history of thromboembolism. Comparison of studies with sample sizes of less than or equal to 99 (risk difference = 0.004; 95% CI, -0.006 to 0.014; P = .40), 100 to 999 (risk difference = 0.004; 95% CI, -0.003 to 0.011; P = .26), and greater than or equal to 1000 (risk difference = -0.001; 95% CI, -0.003 to 0.001; P = .44) showed no association between TXA and incidence of total TEs. Meta-regression of 143 intervention groups showed no association between TXA dosing and risk for venous TEs (risk difference, -0.005; 95% CI, -0.021 to 0.011; P = .53).

CONCLUSIONS AND RELEVANCE

Findings from this systematic review and meta-analysis of 216 studies suggested that intravenous TXA, irrespective of dosing, is not associated with increased risk of any TE. These results help clarify the incidence of adverse events associated with administration of intravenous TXA and suggest that TXA is safe for use with undetermined utility for patients receiving neurological care.

The effect of adjunctive intravitreal conbercept at the end of diabetic vitrectomy for the prevention of post-vitrectomy hemorrhage in patients with severe proliferative diabetic retinopathy: a prospective, randomized pilot study

BACKGROUND

To investigate the effect of intravitreal conbercept (IVC) injections on the incidence of postoperative vitreous hemorrhage (VH) in eyes undergoing surgery for severe proliferative diabetic retinopathy.

METHODS

This was a pilot prospective, comparative, and randomized study. Thirty patients, who underwent vitrectomy for severe proliferative diabetic retinopathy, were assigned randomly to either group 1 (intravitreal conbercept [IVC] injection at the end of pars plana vitrectomy) or group 2 (no IVC injection). Postoperative follow-up was performed on the first day, first week, first month, third month, sixth month and first year after surgery. The primary outcome was the incidence of postoperative VH. Secondary outcomes were the initial time of vitreous clearing (ITVC), best-corrected visual acuity (BCVA) and central retinal thickness (CRT) after surgery.

RESULTS

A total of 30 eyes, from 30 patients, were included. Fifteen eyes were enrolled in the IVC group and fifteen in the control group. The incidence of early and late postoperative VH was not significantly different between the control and IVC groups. ITVC was shorter in the IVC group than that in the control group, but this was not significant (7.38 ± 10.66 vs 13.23 ± 17.35, P = 0.31). Final BCVA, 1 year after surgery, showed significant improvement compared to baseline in both groups. However, analysis of the BCVA at any postoperative visit after surgery showed no significant differences between the two groups. There were two cases of recurrent VH identified at 3 and 6 months after surgery in each group, requiring a second round of surgery. Foveal thickness was significantly different between the two groups at the 3-month, 6-month and 1-year follow-up visits.

CONCLUSIONS

In this pilot study, the effect of IVC injection in reducing the incidence of postoperative VH after diabetic vitrectomy at the end of vitrectomy was not shown.

TRIAL REGISTRATION

The study was registered with the Chinese Clinical Trial Registry. (Reference Number: ChiCTR1800015751).

Exclusion criteria and adverse events in perioperative trials of tranexamic acid: a systematic review and meta-analysis

BACKGROUND

Tranexamic acid (TXA) is an inexpensive therapy effective at minimizing perioperative blood loss and transfusion. However, it remains underutilized due to safety concerns. To date, no evidence-based guidelines exist identifying which patients should not receive TXA therapy. This study determined patient groups for whom safety information regarding TXA is lacking due to common exclusion from perioperative TXA trials.

STUDY DESIGN AND METHODS

A systematic review searching the databases Medline, EMBASE, CENTRAL, and Clinicaltrials.gov was performed. Randomized controlled trials (RCTs) administering systemic TXA perioperatively to elective or emergent surgery patients were eligible. Our primary outcome was to describe exclusion criteria of RCTs, and the secondary outcome was TXA safety. A descriptive synthesis of exclusion criteria was performed, and TXA safety was assessed by meta-analysis.

RESULTS

A total of 268 eligible RCTs were included. Meta-analysis showed that systemic TXA did not increase risk of adverse events compared to placebo or no intervention (relative risk, 1.05; 95% confidence interval, 0.99-1.12). Patient groups commonly excluded from perioperative TXA trials, and thus potentially lacking TXA safety data, were those with major comorbidities, a history of thromboembolism, medication use affecting coagulation, TXA allergy, and coagulopathy. Exclusion of patients with major comorbidities may not be necessary; we showed that the risk of adverse events was similar in studies that excluded patients with major comorbidities and those that did not.

CONCLUSION

Sufficient evidence exists to develop perioperative guidelines for TXA use in many populations. Further studies evaluating perioperative TXA use in patients with a history of thromboembolism are warranted.

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.

PECULIARITIES OF VITRECTOMY AND MORPHOLOGIC CHANGES IN THE EPIRETINAL MEMBRANE AFTER INTRAVITREAL AFLIBERCEPT IN PATIENTS WITH SEVERE PROLIFERATIVE DIABETIC RETINOPATHY

PURPOSE

To examine the peculiarities of vitrectomy and morphologic changes in the epiretinal membrane after intravitreal aflibercept in patients with proliferative diabetic retinopathy.

METHODS

Prospective study of 21 consecutive cases with proliferative diabetic retinopathy complicated by vascularized epiretinal membrane forming tractional retinal detachment that underwent pars plana vitrectomy 4 days after intravitreal injection of aflibercept. After removal, the epiretinal membranes were taken for histologic examination using light microscopy. Obliteration of neovascularization of epiretinal membranes, the lack of bleeding in the intraoperative and early postoperative periods, retinal attachment, and improvement of visual acuity were taken for the criteria of treatment effectiveness.

RESULTS

On the fourth day after intravitreal injection, newly formed vessels of epiretinal membranes were completely obliterated. There was no bleeding during segmentation and delamination of epiretinal membranes during vitrectomy. In the early postoperative period, bleeding complications were not noted. A microscopic examination of epiretinal membranes showed single-thin-walled capillary vessels lined with endothelial cells, the lumen of which does not contain blood cells. Capillaries are submerged in the connective tissue of different degrees of maturity.

CONCLUSION

Intravitreal aflibercept resulted in the obliteration of neovascularization of epiretinal membranes, thus avoiding intraoperative and postoperative bleeding during vitrectomy. The improvement in visual acuity was noted in all cases. Histologic examination of epiretinal membranes determined single-thin-walled capillary vessels lined with endothelial cells without blood cells.

The adjunctive use of pre-operative intravitreal bevacizumab in the setting of proliferative diabetic retinopathy

Purpose

To evaluate the efficacy of pre-operative intravitreal bevacizumab injection on the rate of postoperative vitreous hemorrhage in patients undergoing vitrectomy for complications of proliferative diabetic retinopathy.

Methods

Consecutive retrospective comparative cohort study. Forty eyes of 37 patients who received pre-operative intravitreal bevacizumab 1.25 mg were compared to a similar group of 44 eyes of 44 patients who had undergone vitrectomy surgery prior to the availability and widespread use of pre-operative intravitreal bevacizumab. The primary outcome measure was the incidence of post-vitrectomy hemorrhage at one week after surgery. Secondary outcome measures included are postoperative vitreous hemorrhage at one month and changes in the best-corrected visual acuity (BCVA). For statistical analysis, the paired Student’s t-test and Fisher’s exact test were used.

Results

Four out of 40 eyes (10%) pretreated with intravitreal bevacizumab vs. 12 of 44 eyes (27%) not pretreated with intravitreal bevacizumab had a clinically significant postoperative vitreous hemorrhage at one week. The mean best-corrected visual acuity (BCVA) in bevacizumab group improved from a mean of hand motions to a mean of 20/300 at 1 month (range: 20/25-light perception; p < .001) and mean BCVA in the non-injected group improved from preoperative mean of hand motion to 20/200 at one month follow-up (range: 20/25-no light perception; p < .001). In both groups, 4 patients (12%) needed repeat vitrectomy.

Conclusion

There is a trend to reduced incidence of early post-vitrectomy hemorrhage in patients undergoing vitrectomy for complications of proliferative diabetic retinopathy that have been pre-treated with intravitreal bevacizumab 1 week prior to surgery.

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

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

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Postoperative vitreous hemorrhage after diabetic 23-gauge pars plana vitrectomy

PURPOSE

To report the frequency of postoperative vitreous hemorrhage (VH) in eyes that underwent primary 23-gauge pars plana vitrectomy (PPV) for nonclearing VH resulting from proliferative diabetic retinopathy, as well as associated risk factors.

DESIGN

Retrospective, consecutive, interventional case series.

METHODS

SETTING

Institutional (Retina Service of Wills Eye Institute).

STUDY POPULATION

One hundred seventy-three eyes of 157 patients.

INTERVENTION

Twenty-three-gauge PPV for nonclearing diabetic VH.

MAIN OUTCOME MEASURES

Percentage of eyes in which postoperative VH developed, categorized as early, delayed, or severe persistent, as well as percentage requiring reoperation.

RESULTS

During a mean follow-up of 32 weeks, 56 (32%) of 173 eyes demonstrated postoperative VH, categorized as early (8 eyes; 5%), delayed (13 eyes; 8%), or severe persistent (35 eyes; 20%). Twenty-two (13%) of 173 eyes required reoperation: 4 (50%) of 8 in the early group, 8 (62%) of 13 in the delayed group, and 10 (29%) of 35 in the severe persistent group. Mean preoperative logarithm of the minimum angle of resolution visual acuity was 1.5 (Snellen equivalent, approximately 20/600); mean postoperative VA was 0.65 (Snellen equivalent, approximately 20/90), a gain of 0.85 (P < .0001). Thirty-four (27%) of 127 eyes with complete scatter photocoagulation before undergoing PPV compared with 22 (48%) of 46 eyes with incomplete scatter photocoagulation before undergoing PPV demonstrated postoperative VH (P = .002). Other factors associated with postoperative VH included younger age (P = .022) and phakia (P = .036).

CONCLUSIONS

Postoperative VH was not uncommon after initial 23-gauge PPV for diabetic VH and was associated with incomplete scatter photocoagulation, younger age, and phakia before PPV. However, only a minority of patients required reoperation.

Tranexamic acid: a review of its use in the treatment of hyperfibrinolysis

Tranexamic acid, a synthetic derivative of the amino acid lysine, is an antifibrinolytic agent that acts by binding to plasminogen and blocking the interaction of plasmin(ogen) with fibrin, thereby preventing dissolution of the fibrin clot. Tranexamic acid (Transamin®) is indicated in Japan for use in certain conditions with abnormal bleeding or bleeding tendencies in which local or systemic hyperfibrinolysis is considered to be involved. This article reviews the efficacy and tolerability of tranexamic acid in conditions amenable to antifibrinolytic therapy and briefly overviews the pharmacological properties of the drug. In large, randomized controlled trials, tranexamic acid generally significantly reduced perioperative blood loss compared with placebo in a variety of surgical procedures, including cardiac surgery with or without cardiopulmonary bypass, total hip and knee replacement and prostatectomy. In many instances, tranexamic acid also reduced transfusion requirements associated with surgery. It also reduced blood loss in gynaecological bleeding disorders, such as heavy menstrual bleeding, postpartum haemorrhage and bleeding irregularities caused by contraceptive implants. Tranexamic acid significantly reduced all-cause mortality and death due to bleeding in trauma patients with significant bleeding, particularly when administered early after injury. It was also effective in traumatic hyphaema, gastrointestinal bleeding and hereditary angioneurotic oedema. While it reduces rebleeding in subarachnoid haemorrhage, it may increase ischaemic complications. Pharmacoeconomic analyses predicted that tranexamic acid use in surgery and trauma would be very cost effective and potentially life saving. In direct comparisons with other marketed agents, tranexamic acid was at least as effective as ε-aminocaproic acid and more effective than desmopressin in surgical procedures. It was more effective than desmopressin, etamsylate, flurbiprofen, mefenamic acid and norethisterone, but less effective than the levonorgestrel-releasing intra-uterine device in heavy menstrual bleeding and was as effective as prednisolone in traumatic hyphaema. Tranexamic acid was generally well tolerated. Most adverse events in clinical trials were of mild or moderate severity; severe or serious events were rare. Therefore, while high-quality published evidence is limited for some approved indications, tranexamic acid is an effective and well tolerated antifibrinolytic agent.

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.

Reducing the incidence of early postoperative vitreous haemorrhage by preoperative intravitreal bevacizumab in vitrectomy for diabetic tractional retinal detachment

PURPOSE

 This study aimed to evaluate whether preoperative intravitreal injection of bevacizumab reduces early postoperative vitreous haemorrhage (VH) in vitrectomy for diabetic tractional retinal detachment.

METHODS

We conducted a retrospective chart review of a consecutive, interventional case series. This included 29 eyes (27 patients) in the bevacizumab group and 40 eyes (37 patients) in the non-bevacizumab group. For statistical analysis, each patient was assigned to one of four groups according to the haemostatic modalities used (group 1, none; group 2, only long-acting gas; group 3, only preoperative intravitreal bevacizumab; group 4, both long-acting gas and preoperative intravitreal bevacizumab). The primary outcome measure was the incidence of early postoperative VH. The secondary outcome measure was visual acuity (VA) at 1month.

RESULTS

The incidence of early postoperative VH was highest in group 1 (63%), followed by group 2 (21%), group 3 (20%) and group 4 (5%). Group 3 showed the best visual recovery in the first month. All eyes in group 3 reached VA ≥1/100 at 1month after the operation, compared with 44%, 29% and 42% in groups 1, 2 and 4, respectively.

CONCLUSIONS

Preoperative intravitreal injection of bevacizumab may be useful for reducing early postoperative VH in vitrectomy for diabetic tractional retinal detachment. Eyes receiving preoperative intravitreal bevacizumab without the use of long-acting gas achieved the best visual recovery at 1 month after the operation.

Sulfur Hexafluoride 20% versus Lactated Ringer's Solution for Prevention of Early Postoperative Vitreous Hemorrhage after Diabetic Vitrectomy

PURPOSE

To compare the hemostatic effect of sulfur hexafluoride 20% (SF6 20%) with lactated Ringer's solution for prevention of early postoperative vitreous hemorrhage following diabetic vitrectomy.

METHODS

In a prospective randomized clinical trial, 50 eyes undergoing diabetic vitrectomy were divided into two groups. At the conclusion of surgery, in one group the vitreous cavity was filled with SF6 20% while in the other group lactated Ringer's solution was retained in the vitreous cavity. The two groups were compared for the rate of early postoperative vitreous hemorrhage.

RESULTS

The incidence of vitreous hemorrhage was lower in the SF6 group than the Ringer's group 4 days (20% vs 68%, P=0.001), 7 days (24% vs 60%, P=0.01) and 4 weeks (16% vs 40%, P=0.059) after vitrectomy.

CONCLUSION

In comparison with lactated Ringer's solution, SF6 20% had a significant hemostatic effect especially in the early postoperative period after diabetic vitrectomy and reduced the incidence of vitreous hemorrhage.

Ghost cell glaucoma after intravitreal bevacizumab for postoperative vitreous hemorrhage following vitrectomy for proliferative diabetic retinopathy

BACKGROUND AND OBJECTIVE

To report the occurrence of ghost cell glaucoma after intravitreal injection of bevacizumab for the treatment of postoperative vitreous hemorrhage after vitrectomy for proliferative diabetic retinopathy (PDR).

PATIENTS AND METHODS

Retrospective chart review from August 2006 to December 2007. Patients who had postoperative vitreous hemorrhage after vitrectomy for PDR and received an intravitreal injection of bevacizumab were enrolled in the study.

RESULTS

Eight eyes of 8 patients (mean age: 46 years) were included. After intravitreal injection of bevacizumab, 4 (50%) eyes had clearance of vitreous hemorrhage. Three eyes developed ghost cell glaucoma within 1 week after intravitreal injection of bevacizumab. Of these, intraocular pressure was controlled in 1 eye through the use of anti-glaucoma medication, whereas the other 2 eyes needed surgical intervention to lower intraocular pressure and subsequently clear the vitreous hemorrhage.

CONCLUSION

Intravitreal injection of bevacizumab may accelerate the clearance of postoperative vitreous hemorrhage in cases of PDR. However, a high incidence of ghost cell glaucoma was observed. Caution should be exercised when administering an intravitreal injection of bevacizumab for a postoperative vitreous hemorrhage after vitrectomy for PDR.

[Use of silicone oil in vitreal hemorrhage complicating proliferated diabetic retinopathy]

INTRODUCTION

Vitreous hemorrhage is a frequent complication of proliferated diabetic retinopathy. Vitrectomy has vastly improved its prognosis. The purpose of this study was to evaluate the use of silicone oil in vitreal surgery in this indication.

METHODS

We present a retrospective study of 15 eyes that underwent vitrectomy and silicone oil injection for vitreal hemorrhage complicating proliferative diabetic retinopathy. For each patient, we noted the clinical and echographic features, the surgical procedure, and the postoperative outcome after a mean period of 20 months.

RESULTS

The indications for silicone injection were recurrent vitreal hemorrhage (seven eyes), aggressive fibrovascular proliferations (five eyes), and iatrogenic retinal breaks (three eyes). Anatomic success was noted in ten cases. Four patients had a hemorrhage reoccurrence after silicone oil removal and one patient developed neovascular glaucoma. Silicone cataract (seven eyes) and emulsification of silicone (one eye) were noted.

DISCUSSION

The use of silicone oil in vitreal surgery for complicated proliferated diabetic retinopathy contributes a hemostatic and plugging effect, but it still has a number of disadvantages such as the need to remove it and its own side effects. It can be beneficial in cases of rubeosis or recurrent hemorrhage. However, it is essentially indicated in recurrent hemorrhage in monophthalmos patients.

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

PURPOSE

To evaluate the effects of bevacizumab pretreatment combined with intravitreal infusion of C3F8 10% on the clearance speed of early postoperative vitreous hemorrhage in diabetic vitrectomy for eyes with active fibrovascular proliferation.

DESIGN

Prospective, nonrandomized, comparative case study.

METHODS

Sixteen eyes (15 patients) that underwent primary pars plana vitrectomy for active proliferative diabetic retinopathy (PDR) were prospectively enrolled with a follow-up period of six months or more. These cases received an intravitreal injection of bevacizumab (1.25 mg/0.05 ml) one week prior to surgery and intravitreal C3F8 10% infusion during surgery. The severity of intraoperative bleeding, vitreous clear-up time, percentage of prolonged vitreous clear-up (> or = three weeks), and recurrent hemorrhage respectively were compared with those in a control group (24 eyes in 24 patients) that received gas infusion alone.

RESULTS

The severity of intraoperative bleeding was significantly lower in the study group than in the control group. Vitreous clear-up time for the study group and the control group was 7.2 +/- 5.6 days and 15.2 +/- 11.4 days, respectively (P = .04). Prolonged vitreous clear-up time (> or = three weeks) was observed in one of 16 (6.3%) and nine of 24 (37.5%) of the cases, respectively (P = .03). Early recurrent vitreous hemorrhage rates in the two groups were zero of 16 (0%) and one of 24 (4.2%), respectively (P = .41). Multiple logistic regression analyses showed that bevacizumab pretreatment reduced vitreous clear-up time.

CONCLUSIONS

Bevacizumab pretreatment combined with C3F8 10% infusion could be an effective adjunct to vitrectomy in accelerating postoperative vitreous clear-up for eyes with active PDR.

Intravitreal long-acting gas in the prevention of early postoperative vitreous hemorrhage in diabetic vitrectomy

OBJECTIVE

To evaluate the hemostatic effects of intravitreal infusion of 10% C3F8 in patients undergoing diabetic vitrectomy on the occurrence of early postoperative recurrent vitreous hemorrhage.

DESIGN

Prospective, randomized, observational case series.

PARTICIPANTS

Sixty-one eyes (59 patients) that underwent primary pars plana vitrectomy for complications of proliferative diabetic retinopathy from September 2004 to April 2005, with postoperative retinal reattachment > or = 3 months and follow-up > 6 months were enrolled.

METHODS

Sixty-one cases were randomly divided into either group 1 (intravitreal 10% C3F8 infusion at the end of surgery) or group 2 (no intravitreal gas). Ultrasound biomicroscopy (UBM) examination of the 3 sclerotomy sites was performed at > or = 2 months postoperatively. Demographic data, history, intraoperative findings, and management of recurrent vitreous hemorrhage were recorded.

MAIN OUTCOME MEASURES

Initial time to vitreous clearing (ITVC), percentage of prolonged ITVC (> 5 weeks), and early (< or = 4 weeks) versus late (> 4 weeks) manifest postoperative recurrent vitreous hemorrhage in groups 1 and 2 were compared to determine the effects of 10% C3F8 on prevention of early recurrent vitreous hemorrhage. Multiple logistic regression analyses were performed to examine risk factors related to early recurrent vitreous hemorrhage.

RESULTS

Group 1 ITVC was 13.2+/-9.6 days, and group 2 ITVC was 11.3+/-11.1 days (P = 0.26). Prolonged ITVC (> 5 weeks) in each group was 1/31 (3.2%) and 2/30 (6.7%; P = 0.53). Early manifest recurrent vitreous hemorrhage rates in groups 1 and 2 were 0/31 (0%) and 5/30 (16.7%), respectively (P = 0.02). Early manifest recurrent hemorrhage plus prolonged ITVC in the 2 groups were 1/31 (3.2%) and 7/30 (23.3%), respectively (P = 0.02). The incidences of elevated intraocular pressure, iris neovascularization, and significant cataract formation among the 2 groups were too low to detect statistical significance. No evidence of fibrovascular ingrowth was found by UBM examination in either group. Multiple logistic regression analyses in non-gas-infused cases showed that an increased extent of membrane peeling raised the possibility of significant early vitreous rebleeding.

CONCLUSIONS

Intraocular tamponade with 10% C(3)F(8) may be a useful adjunct to vitrectomy for proliferative diabetic retinopathy in the reduction of early postoperative recurrent vitreous hemorrhage.

Diabetic vitrectomy: risks, prognosis, future trends

PURPOSE OF REVIEW

We review the current standards, risks, prognosis, and indications for diabetic pars plana vitrectomy and consider recent developments in surgical techniques. We also examine surgery's role as a treatment modality for diabetic eye disease among the other accepted and developing treatment options, such as systemic and intravitreal pharmacotherapy.

RECENT FINDINGS

Pars plana vitrectomy for diabetic macular edema and for traction retinal detachment is addressed. Techniques to decrease retinal swelling and ischemia are showing promising results. The use of the smaller 25-gauge and 23-gauge vitrectors is gaining acceptance and offers advantages such as less trauma, less postoperative discomfort, and quicker healing. Techniques are being developed and refined to help prevent postoperative vitreous hemorrhage using cryotherapy around sclerotomy sites and/or endolaser in a near-confluent pattern in an effort to quell fibrovascular ingrowth and subsequent hemorrhage. Finally, pharmacological advances include targeting three levels of intervention: achieving the best glycemic control, correcting altered retinal metabolism secondary to increased glucose availability, and employing neuroprotective and vasoprotective agents.

SUMMARY

The combination of therapies and interventions as they improve and evolve offers the potential to revolutionize the approach to the complications of diabetic eye disease and may soon render many current interventions obsolete. Diabetic pars plana vitrectomy continues to advance with better anatomic and visual success.