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We believe that some issues presented in the article by Kiire et al 1 need to be corrected, and others deserve some further discussion.
Authors in the paragraph on cataract surgery pointed the increased risk of suprachoroidal haemorrhage in patients with high myopia, glaucoma, diabetes, atherosclerotic vascular disease or hypertension referencing to the interesting study,2 which was based only on intracapsular (ICCE) and extracapsular (ECCE) cataract extractions. Both techniques are much more traumatic and are supplemented usually with more invasive than topical form of anaesthesia, however, rarely used today. The dominant technique for cataract surgery is today phacoemulsification with implantation of foldable intraocular lenses (IOLs) through avascular clear corneal incisions under topical anaesthesia. This transformed the surgery into a lower risk procedure. Thus, information given on suprachoroidal haemorrhage in ECCE and ICCE seems to be irrelevant regarding the present risk of this complication during cataract surgery.
Moreover, some important data were not included in the article.
The study based on analysis of the 48 862 patients who were taking aspirin, warfarin, clopidogrel and dipyridamole shown that any complication of a sharp needle or subtenon's cannula local anaesthetic block was increased in patients taking clopidogrel, warfarin, versus non-users, but no increase in potentially sight-threatening complications, including choroidal/suprachoroidal haemorrhage and hyphaema was identified.3 The Royal College of Ophthalmologists of the United Kingdom (RCOphth) published guidelines on the perioperative management of the anticoagulated patient.4 These recommendations reported that
warfarin is effective at reducing life-threatening thrombotic events;
stopping warfarin increases the risk for stroke to 1 in 100;
the international normalised ratio (INR) should be checked to ensure that a patient is within the desired therapeutic range;
with needle local anaesthesia, the risk of orbital haemorrhage is increased from 0.2% to 1.0%;
consideration should be given to use of topical anaesthesia or sub-Tenon’s block.
It was also pointed that since anticoagulant and antiplatelet medications are taken to reduce the incidence of potentially life-threatening thromboembolic events in patients with cardiovascular conditions, it is desirable to continue them before surgery as long as they do not threaten the success of cataract surgery.4
Prospective cohort studies in cataract surgery showed an incidence of clinically important bleeding of up to 3%. However, Baron et al 5 have recently proposed continuation of antithrombotic agents in patients undergoing cataract surgery since this procedure is considered to be associated with a low risk of bleeding (<1.5%).
Interestingly, none of original studies presenting the original data in relation to the risk of anticoagulants and/or antiplatelet therapy in cataract surgery during the period 2007–2013 was presented nor discussed in the article.
It was also presented a systematic review of the literature that patients under treatment with warfarin who underwent cataract surgery without anticoagulant interruption had a threefold greater risk for haemorrhage than non-anticoagulated patients who have cataract surgery.6 However, most of the bleeding was self-limiting without clinical consequences, consisting in microhyphema and subconjunctival haemorrhage segments. They reported only one potentially serious retrobulbar haemorrhage in patients under anticoagulation therapy, whereas six retrobulbar bleeds had been observed in non-anticoagulated patients. Furthermore, there was no evidence that perioperative continuation of warfarin had a deleterious impact on postoperative visual acuity or bleeding risk.
In conclusion, we argue that the risk of a cardiovascular event among patients in whom anticoagulant and antiplatelet agents are discontinued is higher than the risk of bleeding during cataract surgery among patients who continue to receive these drugs.
Contributors All authors substantially contributed to the conception or design of the work, and the acquisition, analysis or interpretation of data; drafting the work and revising it critically for important intellectual content; and finally approved the version submitted.
Competing interests None.
Provenance and peer review Not commissioned; internally peer reviewed.