HEMORRHAGIC RISK OF VITREORETINAL SURGERY IN PATIENTS MAINTAINED ON NOVEL ORAL ANTICOAGULANT THERAPY

Antiplatelets and Anticoagulants in Vitreoretinal Surgery: A Systematic Review

Background: Antiplatelets and anticoagulants have substantially influenced contemporary vitreoretinal surgical practices. The availability of new oral blood thinners has recently spurred a renewed interest in the clinical approach to vitreoretinal surgical conditions since it may be difficult for the surgeon to collect sufficient evidence-based data to decide whether to discontinue or continue such medications. Materials and Methods: We conducted a systematic review on the use of antiplatelets and/or anticoagulants in the perioperative setting in vitreoretinal surgery and their possible complications, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The level of evidence, according to the Oxford Centre for Evidence-Based Medicine (OCEM) 2011 guidelines, and the quality of evidence, according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system, were assessed for all included articles. Results: In total, 2310 articles were initially extracted, out of which 1839 articles were obtained after duplicates were removed and their abstracts were screened. A total of 27 articles were included in the full-text review. Finally, a remaining 22 articles fulfilled the inclusion criteria. Conclusions: Even though there is just a small number of studies with solid results, the advantage of using antiplatelets and/or anticoagulants in vitreoretinal surgery seems to outweigh the disadvantages, which are mainly related to postoperative hemorrhagic complications.

Risk Factors for Severe Bleeding Complications in Glaucoma Surgery and the Role of Antiplatelet or Anticoagulant Agents

Purpose

To evaluate the influences and risk factors for severe bleeding complications during glaucoma surgery, and to investigate the role of antiplatelet (AP) and anticoagulant (AC) agents.

Methods

This prospective study enrolled patients undergoing trabeculectomy, trabeculotomy (with Trabectome® or Kahook Dual Blade®), viscocanaloplasty and Ahmed or Baerveldt implants. Bleeding severity was graded on an ordinal scale ranging from 0 to 5. Immediately after surgery and one day later, the incidence and severity of bleeding events was documented on a standardized form. A grade ≥3 was defined as severe bleeding. The influence of known systemic disorders, the type of anesthesia, surgical procedure, intraoperative blood pressure, and the use of or change in AP or AC agents on intraoperative bleeding were analyzed.

Results

Data from 89 eyes undergoing glaucoma procedures were included (age 71.3y ± 10.5). We observed severe intraoperative bleeding in 8 eyes (9%) and found that concomitant diseases such as the history of a deep vein thrombosis or peripheral arterial occlusive disease, and the type of surgical procedure (trabeculectomy and viscocanaloplasty) were significantly associated with severe bleeding events. By contrast, the use of AP/ AC agents had no significant influence on severe intraoperative bleeding events.

Conclusion

According to the results of our study cohort, glaucoma procedures entailing scleral manipulations (trabeculectomy and viscocanaloplasty) and concomitant diseases such as the history of a deep vein thrombosis or peripheral arterial occlusive disease influence the risk of severe intraoperative bleeding events, we detected no increased risk related to concomitant antiplatelet and/ or anticoagulant medication use.

Haemorrhagic complications following cataract and vitreoretinal surgery with sub-Tenon's block in patients receiving non-vitamin K oral anticoagulant agents: A prospective audit

There is a lack of data to support either continuation or interruption of non-vitamin K oral anticoagulants for cataract and vitreoretinal surgery. A prospective audit was undertaken of 291 patients undergoing cataract surgery or vitreoretinal surgery, predominantly under sub-Tenon's block, while continuing these agents. The median time from last non-vitamin K oral anticoagulant dose to the insertion of sub-Tenon's block was five hours. No patient required emergency reversal of anticoagulation. There were no sight-threatening complications in the immediate perioperative period, although two vitreoretinal patients (3.8%) had a moderate haemorrhagic complication on day five, and two cataract patients (0.8%) had a minor haemorrhagic complication on days one and 14 postoperatively. Despite continuing their non-vitamin K oral anticoagulants, three (1%) cataract patients had a moderate thromboembolic complication within the 30-day postoperative period. The risk of haemorrhagic complications associated with continuation of anticoagulation with non-vitamin K oral anticoagulants for cataract and vitreoretinal surgery is low, and this audit supports the continuation of non-vitamin K oral anticoagulants for our patients having cataract and vitreoretinal surgery.

Risk Factors for Severe Bleeding Complications in Vitreoretinal Surgery and the Role of Antiplatelet or Anticoagulant Agents

PURPOSE

To evaluate the influences and risk factors for severe bleeding complications during vitreoretinal surgery and to investigate the role of antiplatelet and anticoagulant agents.

DESIGN

Prospective trial.

PARTICIPANTS

Patients undergoing vitreoretinal surgery.

METHODS

The procedures included were pars plana vitrectomy and scleral buckling. We developed a uniform classification to grade the bleeding severity. Bleeding was graded on an ordinal scale ranging from 0 to 5. Immediately after surgery and 1 day later, the incidence and the severity of bleeding events was documented on a standardized form. A grade of 3 or more was defined as severe bleeding. Furthermore, the influence of known systemic disorders before surgery, the type of anesthesia, type of surgical procedure, intraoperative blood pressure, and the use or change of antiplatelet or anticoagulant agents on intraoperative bleeding was analyzed.

MAIN OUTCOME MEASURES

Incidence and risk factors for severe intraoperative bleeding events.

RESULTS

Data from 374 eyes undergoing vitreoretinal procedures were included in our study (mean age, 67.6 ± 12.9 years). A severe intraoperative bleeding event was observed in 15 eyes (4%). We found that concomitant diseases such as diabetes mellitus and carotid artery stenosis, the presence of diabetic retinopathy, younger age, and scleral buckling combined with a transscleral puncture were associated significantly with severe bleeding events. By contrast, use of antiplatelet or anticoagulant agents, or both, had no significant influence on severe intraoperative bleeding events.

CONCLUSIONS

Although external manipulations during buckling surgery (e.g., drainage of subretinal fluid) and concomitant diseases such as diabetes mellitus and carotid artery stenosis influences the risk of severe intraoperative bleeding events, we did not detect an increased risk related to coexisting antiplatelet or anticoagulant medication use, or both.

Comparative Incidence of Postoperative Hemorrhage in Vitreoretinal Surgery in Patients on Anti-Coagulants

BACKGROUND AND OBJECTIVE

Data regarding hemorrhagic complications of direct oral anticoagulants (DOACs) and vitreoretinal surgery are limited.

PATIENTS AND METHODS

Multicenter analysis of longitudinal, aggregated electronic health records of patients undergoing pars plana vitrectomy (PPV) with no prior history of ocular hemorrhage. Retrospective analysis of patients undergoing PPV between January 1, 2013, and December 31, 2019. The main outcomes were development of postoperative hemorrhagic complications within 1 month following vitreoretinal surgery.

RESULTS

A total of 58,131 eyes underwent PPV, with 2,956 (5.1%) on anticoagulant medication prior to surgery. Eight hundred twenty-eight eyes (1.4%) developed a postoperative hemorrhage. Of eyes with anticoagulation use, 50 of 2,956 (1.29%) developed a hemorrhage, whereas 778 of 55,175 (1.41%) of the eyes with no prior anticoagulation use developed a postoperative hemorrhage (P = .2107).

CONCLUSION

Use of DOACs prior to vitreoretinal surgery does not appear to be associated with increased rates of postoperative intraocular hemorrhage. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:374-379.].

Update on the perioperative management of antiplatelets and anticoagulants in ophthalmic surgery

INTRODUCTION

Anti-thrombotic drugs (antiplatelets and anticoagulants) are widely used for different clinical reasons. This means that there are an increasing number of patients undergoing elective ophthalmic surgery that are being treated with these drugs. A better knowledge of their implications and their peri-operative use may help to prevent surgical and secondary adverse events. There is often no firm recommendation on how to manage certain drugs in certain surgeries.

OBJECTIVE

To review the recommendations in the scientific literature as regards managing anti-thrombotic agents during the peri-operative period of ophthalmic surgery.

MATERIAL AND METHODS

A review was made of the relevant guidelines and studies using an antiplatelet and anticoagulant drugs approach for cataract, vitreo-retinal, glaucoma, oculoplastic, and strabismus surgeries.

RESULTS

Recommendations about whether to continue or discontinue anti-thrombotic drugs in the peri-operative period of different ophthalmic surgical fields are presented.

CONCLUSIONS

There are only firm recommendations of maintaining anti-thrombotic drugs as regards cataract surgery using phacoemulsification with topical anaesthesia. In other surgical fields, ophthalmologists should balance the risk of thromboembolic events and risks of haemorrhagic complications in order to carry out a proper management. A multi-disciplinary approach is recommended for complex cases. Additional studies should be performed to better characterise the peri-operative use of anti-thrombotic agents in order to prepare clinical guidelines for ophthalmic surgery.

Update on the perioperative management of antiplatelets and anticoagulants in ophthalmic surgery

INTRODUCTION

Anti-thrombotic drugs (antiplatelets and anticoagulants) are widely used for different clinical reasons. This means that there are an increasing number of patients undergoing elective ophthalmic surgery that are being treated with these drugs. A better knowledge of their implications and their peri-operative use may help to prevent surgical and secondary adverse events. There is often no firm recommendation on how to manage certain drugs in certain surgeries.

OBJECTIVE

To review the recommendations in the scientific literature as regards managing anti-thrombotic agents during the peri-operative period of ophthalmic surgery.

MATERIAL AND METHODS

A review was made of the relevant guidelines and studies using an antiplatelet and anticoagulant drugs approach for cataract, vitreo-retinal, glaucoma, oculoplastic, and strabismus surgeries.

RESULTS

Recommendations about whether to continue or discontinue anti-thrombotic drugs in the peri-operative period of different ophthalmic surgical fields are presented.

CONCLUSIONS

There are only firm recommendations of maintaining anti-thrombotic drugs as regards cataract surgery using phacoemulsification with topical anaesthesia. In other surgical fields, ophthalmologists should balance the risk of thromboembolic events and risks of haemorrhagic complications in order to carry out a proper management. A multi-disciplinary approach is recommended for complex cases. Additional studies should be performed to better characterise the peri-operative use of anti-thrombotic agents in order to prepare clinical guidelines for ophthalmic surgery.

Perioperative risk of bleeding with antithrombotic agents in macular surgery: a national, prospective, multicentre study

PURPOSE

To compare the risk of haemorrhagic complications in elective macular surgery between patients with no antithrombotic (AT) treatment (defined as patients with no history of AT therapy or who discontinued AT therapy) and patients who continued AT treatment during the surgery.

METHODS

E-case report forms were prospectively recorded in a database before vitreoretinal surgery and 1 month after. Data on patient characteristics, surgical techniques, haemorrhagic complications and antithrombotic status were collected. Patients with retinal detachment, proliferative diabetic retinopathy and previous retinal haemorrhage were excluded.

RESULTS

A total of 748 procedures (single procedure in one eye per patient) were performed between January and May 2019. Among them, 202 patients (27.0%) were treated with antithrombotic therapy at the time of surgery: 19.5% with antiplatelet agents (n = 146), 6.3% with anticoagulants (n = 47) including 3.2% (n = 24) patients treated with novel oral anticoagulants, 0.8% (n = 6) with anticoagulants and antiplatelet agents, and 0.4% (n = 3) with heparin. Overall, 92 patients (12.3%) developed one or more haemorrhagic complications, of which 63 (11.5%) and 29 (14.4%) were in the non-AT and AT group, respectively. The multivariate logistic regression model showed no difference between AT treatment groups regarding ocular bleeding complications (odds ratio [OR] 1.2, 95% confidence interval (CI) [0.7-2.2], p = 0.54).

CONCLUSION

No cases of uncontrolled or severe perioperative haemorrhage in patients continuing antithrombotic agents were reported in this selected population. For the majority of the patients taking antiplatelets or anticoagulants, these agents could be safely continued during macular surgery.

Management of Anticoagulation and Antiplatelet Therapy in Glaucoma Surgery

The use of antithrombotic therapy is rising as the population of older adults grows and novel agents with wider indications emerge. Likewise, surgical treatment of glaucoma may become increasingly common as the prevalence of glaucoma increases and innovative treatment options are developed. These trends highlight the need to understand how best to manage antithrombotic therapy in the context of glaucoma surgery. This review article describes current literature on antithrombotic therapy and perioperative thromboembolic risk evaluation based on individual factors. In addition, guidance is offered on the management of antithrombotic therapy in the setting of each type of glaucoma surgery, with an emphasis on a multidisciplinary approach involving the patients' treating physicians.

Efficacy and safety of non-vitamin K-antagonist oral anticoagulants for retinal vascular diseases in patients with atrial fibrillation: Korean cohort study

We investigated the prevalence of retinal vascular occlusion and intraocular bleeding and compare their risks in patients undergoing anticoagulant therapy, either with non-vitamin K-antagonist oral anticoagulants (NOAC) or warfarin. We performed a cohort study (January 2015 to April 2018) in 281,970 patients with nonvalvular atrial fibrillation (AF) using health claims in the nationwide database of the Health Insurance Review and Assessment service of Korea. A Cox-proportional hazard regression was used to calculate the hazard ratio (HR) for retinal vascular occlusion or intraocular bleeding. The HR of retinal vascular occlusion was estimated to 1.59 (95% confidence interval [CI], 1.35–1.86) for NOAC users compared to that with warfarin users. Among the various types of NOACs, all NOACs showed higher risk of retinal vascular occlusion than did warfarin. For intraocular bleeding, the HR was estimated to be 0.86 (95% CI, 0.75–0.98) for NOAC users compared with that with warfarin users. The risk of retinal vascular occlusion was higher in NOAC users than in warfarin users, while the risk of intraocular bleeding was lower with NOAC therapy. NOACs were not found to be as effective as warfarin for retinal vascular occlusion, but safe in terms of intraocular bleeding.

Perioperative Management of Anticoagulants in Ocular Surgeries

Use of anticoagulant therapy has increased in patients presenting for ophthalmic surgery over the past decade. The decision of whether or not to discontinue anticoagulant medications prior to ophthalmic surgeries is nuanced and ultimately based on multiple factors including the type of surgery and the patient’s comorbidities and risk profile. In the setting of cataract surgery, no increased risk of bleeding with anticoagulation was observed in a large prospective study, which suggests that anticoagulation should not be interrupted for the average-risk patient on anticoagulation. In other types of ophthalmic surgery, expert opinion and studies are divided on the perioperative management of anticoagulant therapy. Preoperative thromboembolic risk stratification, intraoperative techniques to minimize bleeding, and postoperative management are also reviewed to generate more comprehensive recommendations on ophthalmic perioperative management of anticoagulation.

Randomised controlled trial on vitreoretinal surgery with and without oral anticoagulants: surgical complications, visual results and perioperative thromboembolic events

BACKGROUND

Vitreoretinal surgery in anticoagulated patients is a challenging situation for vitreoretinal surgeons, who have to choose between being faced with the systemic thromboembolic risks that the interruption of anticoagulation involves, or the intra- and postoperative haemorrhagic risks associated with maintenance of this therapy. So far, no trial has compared, in a prospective and randomized manner, perioperative complications and the visual results associated with continuation or interruption of oral anticoagulant therapy before pars plana vitrectomy (PPV) under retrobulbar anaesthesia. The main objective of this trial is to compare haemostasis-related perioperative complications of PPV in patients maintaining anticoagulant therapy before surgery compared to patients with an interruption in this therapy before surgery.

METHODS

Ninety-six patients will be randomly assigned to either the control group, in whom oral anticoagulant therapy will be interrupted and substituted with subcutaneous heparin according to local clinical practice, or the intervention group in whom oral anticoagulant therapy will not be interrupted before surgery. Patients will be stratified according to the oral anticoagulant they were taking (direct or indirect anticoagulation). They will be followed up for 12 weeks, and the primary outcome, and haemorrhagic complications until 15 days after surgery, will be evaluated.

DISCUSSION

This trial will provide novel information on the possibility of continuing anticoagulant therapy during PPV. The benefits expected from the change in the current surgical management paradigm for anticoagulated patients would be a decreased risk in the incidence of perioperative thromboembolic events and the possibility of performing surgery without delay and without the need for patients to change their usual anticoagulation protocol to the more complex and less safe substitutive therapy.

TRIAL REGISTRATION

Clinical Trials Register EudraCT, 2018-000753-45. Registered on 11 November 2018.

Safety of cataract surgery in patients treated with the new oral anticoagulants (NOACs)

PURPOSE

To evaluate the safety of phacoemulsification of cataract in patients taking new oral anticoagulants (NOACs).

METHODS

In a prospective case series, consecutive patients on NOACs (dabigatran, rivaroxaban, or apixaban) who were referred for uncomplicated cataract surgery to the eye institute underwent a thorough ophthalmological and hematological evaluation. Rivaroxaban and apixaban anti-factor Xa tests, and diluted thrombin time for dabigatran, were used for monitoring anticoagulation levels in blood. Blood was drawn for these tests just prior to surgery and at a peak level of the drug at about 4 h post-surgery (2 h after the drug was given). All surgeries were videotaped and patients were examined at 1 and 7 days after the operation. The main outcome measures included assessment of intra-operative, postoperative ocular bleeding, and other related complications.

RESULTS

Thirty-five eyes of 25 unrelated patients ranging in age from 63 to 92 years (mean 77.6 years) underwent phacoemulsification. Intra-operative bleeding was observed in 5 eyes from the conjunctiva or limbus at the main incision site. No intraocular bleeding occurred. No hemorrhagic complications were observed during the 1-week follow-up. According to anti-factor Xa levels prior to surgery and following surgery, 85% of the patients were on therapeutic levels of NOACs.

CONCLUSIONS

Clear corneal incision phacoemulsification performed under topical anesthesia can be safely performed in simple cases of cataract without discontinuing NOAC treatment.

Peri-operative management of ophthalmic patients on anti-thrombotic agents: a literature review

There is variability in the management of ophthalmic patients on anti-thrombotic agents (antiplatelets and anticoagulants) during the peri-operative period. A survey carried out in a UK teaching hospital on a cohort of ophthalmologists showed majority were comfortable with antiplatelet management but there was variability in managing patients on warfarin and direct oral anticoagulants (DOACs); 40% were unaware of existing guidelines. We aim to review the recommendations in the literature with regards to managing anti-thrombotic agents during the peri-operative period of ophthalmic surgery. We reviewed incidences of complications, specifically, the haemorrhagic complications associated. Pubmed search was carried out on relevant keywords from January 2007 to August 2017. All relevant UK guidelines including the Royal College of Ophthalmologists and British Society of Haematology were reviewed. Literature recommendations for routine cataract surgery under topical or sub-Tenon's anaesthesia would be to continue all anti-thrombotic agents. For sharp needle anaesthesia, avoidance of dual antiplatelet therapy was recommended and warfarin could be continued if INR within therapeutic range. Recommendations for surgeries in glaucoma, vitreo-retinal, oculoplastic and lacrimal; and strabismus are presented. No evidence was found for corneal surgery. Haemorrhagic complications are reported in all groups. Limitations of this review include the retrospective nature, lack of randomized control trials and the limited evidence regarding DOACs. It is important for ophthalmologists to be aware of and balance the risk of thromboembolic events and risks of haemorrhagic complications for ophthalmic surgery. A multi-disciplinary approach is recommended for complex cases.

Association of Novel Oral Antithrombotics With the Risk of Intraocular Bleeding

Importance

Novel oral anticoagulation and antiplatelet therapies have become a mainstay of treatment for thromboembolic disease. However, the safety profile of these medications has not been completely characterized.

Objective

To determine the risk of developing intraocular hemorrhages with novel oral antithrombotic therapy compared with that of traditional antithrombotic agents.

Design, Setting, and Participants

In this retrospective cohort study, a large national insurance claims database was used to generate 2 parallel analyses. All patients with incident use of dabigatran etexilate or rivaroxaban between January 1, 2010, and September 30, 2015, were compared with patients with incident use of warfarin sodium. Similarly, patients with new use of prasugrel hydrochloride were compared with those with new use of clopidogrel bisulfate. Both analyses required the patient to be in the insurance plan for at least 24 months prior to initiation of therapy and excluded patients with any previous diagnosis of intraocular hemorrhages or any prescription for the comparator medications. Furthermore, the antiplatelet analysis required a diagnosis of acute coronary syndrome or a myocardial infarction within 60 days of initiation of pharmacologic therapy. The anticoagulant analysis excluded patients with end-stage renal disease, renal transplants, and those with heart valve disease.

Main Outcomes and Measures

Incident intraocular hemorrhages at 90 and 365 days. Multivariate Cox proportional hazards regression models were used to compare the hazard ratio (HR) of developing an intraocular hemorrhage in individuals taking novel agents compared with those taking traditional medications.

Results

A total of 146 137 patients taking warfarin (76 714 women and 69 423 men; mean [SD] age, 69.8 [11.8] years) were compared with 64 291 patients taking dabigatran or rivaroxaban (31 576 women and 32 715 men; mean [SD] age, 67.6 [11.7] years). Cox proportional hazards regression revealed a decreased hazard for developing an intraocular hemorrhage with dabigatran or rivaroxaban at 365 days (HR, 0.75; 95% CI, 0.58-0.97; P = .03), but not at 90 days (HR, 0.73; 95% CI, 0.22-2.63; P = .13). A total of 103 796 patients taking clopidogrel (37 578 women and 66 218 men; mean [SD] age, 68.0 [11.3] years) were compared with 8386 patients taking prasugrel (1988 women and 6380 men; mean [SD] age, 61.0 [9.6] years) and no increased hazard for developing an intraocular hemorrhage with prasugrel was seen at 90 days (HR, 0.75; 95% CI, 0.29-1.92; P = .55) or 365 days (HR, 1.19; 95% CI, 0.69-2.04; P = .53).

Conclusions and Relevance

These results suggest a decreased risk of intraocular hemorrhage associated with novel direct thrombin inhibitors and direct factor Xa inhibitors, but no difference for P2Y12 inhibitors compared with traditional vitamin K anticoagulation and antiplatelet therapy, respectively.

Risk of Intraocular Bleeding With Novel Oral Anticoagulants Compared With Warfarin: A Systematic Review and Meta-analysis

Importance

It is unclear if the risk of intraocular bleeding with novel oral anticoagulants differs compared with warfarin.

Objective

To characterize the risk of intraocular bleeding with novel oral anticoagulants compared with warfarin.

Data Sources

A systematic review and meta-analysis was undertaken in an academic medical setting. MEDLINE and ClinicalTrials.gov were searched for randomized clinical trials published up until August 2016. This search was supplemented by manual bibliography searches of identified trials and other review articles.

Study Selection

Studies were eligible for inclusion if they were phase 3 randomized clinical trials, enrolled patients with atrial fibrillation or venous thromboembolism, compared a novel oral anticoagulant (dabigatran, rivaroxaban, apixaban, or edoxaban) with warfarin, and recorded event data on intraocular bleeding. Data on intraocular bleeding were pooled using inverse-variance, weighted, fixed-effects meta-analysis.

Data Extraction and Synthesis

The PRISMA guidelines were used for abstracting data and assessing quality. Independent extraction was performed by 2 investigators.

Main Outcomes and Measures

Intraocular bleeding events and associated risk ratio for novel oral anticoagulants compared with warfarin.

Results

Twelve trials investigating 102 627 patients were included. Randomization to novel oral anticoagulants was associated with a 22% relative reduction in intraocular bleeding compared with warfarin (risk ratio, 0.78; 95% CI, 0.61-0.99). There was no significant heterogeneity observed (I2 = 4.8%, P = .40). Comparably lower risks of intraocular bleeding with novel oral anticoagulants were seen in subgroup analyses, with no significant difference according to the indication for anticoagulation (P for heterogeneity = .49) or the novel oral anticoagulant type (P for heterogeneity = .15). Summary estimates did not differ materially when random-effects meta-analytic techniques were used.

Conclusions and Relevance

These results suggest that novel oral anticoagulants reduce the risk of intraocular bleeding by approximately one-fifth compared with warfarin. Similar benefits were seen in both patients with atrial fibrillation and venous thromboembolism. Our data have particular relevance for patients at higher risk of spontaneous retinal and subretinal bleeding. These findings may also have important implications in the perioperative period, in which the use of novel oral anticoagulants may be superior. Future studies are required to better characterize the optimal management of patients with both ophthalmic disease and cardiovascular comorbidities requiring anticoagulation.