Introduction Warfarin is a commonly used anticoagulant whose effect in vitreoretinal surgery has not been well studied.

Methods A series of 60 patients on warfarin therapy undergoing pars plana vitrectomy were retrospectively case controlled to 60 patients with similar presenting complaints. In addition, an online survey was performed of current practice in the UK.

Results 2% of the patients receiving vitrectomy were on warfarin. There were 33 males and 27 females with a median age of 72.5 years; follow-up was for a mean of 0.88 years. The international normalised ratio (INR) ranged between 0.94 and 4.6 (median 2.3). Two cases of suprachoroidal haemorrhages occurred in the control group (one with preoperative choroidal haemorrhage from dislocated lens nucleus), while none occurred in the warfarin group. 12 patients with rhegmatogenous retinal detachment (RRD) in the warfarin group presented with vitreous haemorrhage compared with only four in the control group (p=0.04). From the online survey, 48 respondents (81%) would ask patients to withhold warfarin prior to vitreoretinal surgery based on the INR.

Conclusions There was no increase in complications in patients continuing to take warfarin compared with controls. Patients with RRD are more likely to have vitreous haemorrhage at presentation if they are on warfarin.