Proliferative vitreoretinopathy (PVR) is a retinal scarring process which occurs following retinal detachment. It is a major cause of failure of retinal reattachment surgery and impairment of ultimate visual recovery. Low weight molecular heparin (LMWH) and 5-Fluorouracil (5-FU) are agents that can be used during surgery to potentially reduce the amount of PVR following surgery.
The two studies included in this review looked at using LMWH with 5-FU during retinal detachment repair to see if there was an effect of reducing PVR levels after surgery. One study focused on patients who are considered at high-risk of developing PVR after surgery because of pre-existing ocular features, and found beneficial effects of this treatment in this group. The other study looked at a wider group of patients and did not find a benefit in using this combination treatment, and in certain patients the treatment was associated with poorer vision. Due to the inconsistency of the evidence, until further data are available, future research on the use of LMWH with 5-FU should be conducted only in retinal detachment patients who are likely to develop considerable retinal scarring after surgery.
Results from this review indicate that there is inconsistent evidence from two studies on patients at different risk of PVR on the effect of LMWH and 5-FU used during vitrectomy to prevent PVR. Future research should be conducted on high risk patients only, until a benefit is confirmed at least in this patient subgroup.
Proliferative vitreoretinopathy (PVR) is a significant cause of failure in retinal reattachment surgery. Various pharmacological agents have shown potential benefit in reducing postoperative PVR risk.
This review aimed to compare the use of intravitreal low molecular weight heparin (LMWH) alone or with 5-Fluorouracil (5-FU) versus placebo, as an adjunct in the prevention of PVR following retinal reattachment surgery.
We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 9), MEDLINE (January 1950 to October 2012), EMBASE (January 1980 to October 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the 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 15 October 2012.
We only included randomised controlled trials (RCTs) that compared intravitreal LMWH alone or with 5-FU, versus placebo for the prevention of postoperative PVR in patients undergoing primary vitrectomy for rhegmatogenous retinal detachment repair.
Two review authors independently assessed trial quality and extracted data. The review authors contacted study authors for additional information.
We included two RCTs (with a total of 789 participants) comparing LMWH with 5-FU infusion and placebo. However, we did not perform a meta-analysis because of significant heterogeneity between these studies. One study found a significant beneficial effect of LMWH with 5-FU in reducing postoperative PVR compared to placebo (RR: 0.48, 95% confidence interval: 0.25 to 0.92), in 174 patients who were viewed at high-risk of developing postoperative PVR. The other study included 615 unselected cases of rhegmatogenous retinal detachment and could not show a difference between LMWH with 5-FU infusion and placebo in reducing PVR rates (RR:1.45, 95% confidence interval: 0.76 to 2.76).