Methodological quality of the review: Low confidence

Author: Lip GYH, Durrani OM, Roldan V, Lip PL, Marin F, Reuser TQ.

Region: Details not provided

Sector: Antithrombotic therapy, ophthalmic patients, cataract surgery and glaucoma surgery

Sub-sector: Aspirin, warfarin

Type of cataract: Age-related cataract

Equity focus: None specified

Review type: Effectiveness review

Quantitative synthesis method: Narrative analysis

Qualitative synthesis methods: Not applicable

Background

Increasing numbers of patients who undergo ophthalmic surgery (including cataract, glaucoma and vitreoretinal surgery) use anticoagulant and antiplatelet therapy such as warfarin and aspirin. Authors note that these drugs are routinely discontinued preoperatively because of the perceived risk of intra or post-operative severe bleeding. However, authors argue that this practice is not based on published evidence and that risks to the patient are not fully understood.

Research objectives

The aim of this review was to provide a semi-systematic review of the current published evidence on the perioperative management of anticoagulant and antiplatelet therapy. In particular, we will review the risk of significant bleeding in patients on anticoagulant and anti-platelet therapy and determine what types of ophthalmic procedures are safer than others.

Main findings

32 retrospective or prospective studies were included in this review. Based on the literature, authors concluded that:

• Aspirin and warfarin should not be discontinued prior to the use of local anaesthetic;
• In the presence of ‘vasculopathic risk factors’, aspirin should not be stopped before any type of ophthalmic surgery;
• Cataract surgery can be safely carried out in patients taking aspirin or warfarin;
• With the exception of vitreoretinal surgery (as no evidence found) warfarin should be continued in patients undergoing ophthalmic surgery as the risk of thrombophilia is higher than the risk of significant bleeding.

Authors suggested that current evidence supports the continued use of aspirin and, with some exceptions, warfarin in the perioperative period. For most types of surgical procedures, the risks of interrupting anticoagulation outweigh its benefits but clinical needs may dictate the disruption of warfarin or aspirin.

The retrospective and prospective studies included in the review were small and authors recommend that high-quality prospective randomized studies should be conducted to further define and influence the risk of thrombotic complications.

Methodology

Authors conducted a search of MEDLINE, EMBASE and the Database of Abstracts of reviews Of Effects (DARE) and Cochrane Controlled trials register and Cochrane systematic reviews for published data between 1970 and 2009. It was not clear if there were any language restrictions, and whether the screening and data extraction of articles were conducted independently by two reviewers.

Authors conducted a narrative synthesis of the data. The review lists the studies included in the review, the interventions, results and strength of evidence. However, the study designs and quality assessment criteria of included studies were not reported. More detail around methods and outcomes and quality assessment used to conduct this review are provided as web-only supplementary material and not included in the review itself. Supplementary material was not found as of 4 July 2014.

Applicability/external validity

The review did not directly discuss the external validity of the findings from the review although did recognize that the review largely relied upon limited quality and quantity of evidence, therefore potentially limiting its applicability.

Geographic focus

The geographical location of the included studies was not reported by the review authors.

Quality assessment

Authors noted that details in regards to the methodology used to conduct this review were provided as a web-only supplementary material and not included in this review. Nevertheless, as this supplementary information was not available, quality assessment was based on the information provided in this review only. The authors conducted a narrative synthesis of included studies although, due to lack of information in the review itself on its methodology, it is not clear if meta-analysis of the data would have been possible or preferred.

Authors made some strong recommendations and conclusions on the back of the review, however limitations to the review were reported, that is the quality of a number of the included studies was rated as ‘weaker evidence consisting of small non-comparative case series and case reports’. Therefore, low confidence was awarded to the conclusions about the effects of this study.