Post-operative 5-Fluorouracil for glaucoma surgery

Abstract

Background: Trabeculectomy is performed as a treatment for many types of glaucoma in an attempt to lower the intra-ocular pressure. The surgery involves creating a channel through the sclera, through which intra-ocular fluid can leave the eye. If scar tissue blocks the exit of the surgically created channel intra-ocular pressure rises and the operation fails. Antimetabolites such as 5-Fluorouracil are used to inhibit wound healing to prevent the conjunctiva scarring down on to the sclera.

Objectives: The objective of this review is to assess the effects of post-operative injections of 5-Fluorouracil in eyes of people undergoing surgery for glaucoma.

Search strategy: We searched the Cochrane Controlled Trials Register - CENTRAL (which includes the Cochrane Eyes and Vision Group specialised register), MEDLINE and EMBASE. We searched the reference lists of relevant articles for additional trials, and we used the Science Citation Index to search for articles that cited the included studies. We contacted investigators and experts for details of additional relevant trials.

Selection criteria: We included randomised trials of post-operative 5-Fluorouracil injections compared to placebo injections or no injections in trabeculectomy for glaucoma.

Data collection and analysis: Two reviewers independently assessed trial quality and extracted data. We contacted trial investigators for missing information. Data were summarised using relative risk, Peto odds ratio and weighted mean difference as appropriate.

Main results: Nine trials, which randomised a total of 614 participants, are included in the review. As far as can be determined from the trial reports, the methodological quality of the trials was not high. When delivered by post-operative injection, 5-Fluorouracil appears to be effective in reducing the likelihood of surgical failure of trabeculectomy both in eyes at high risk of failure and those undergoing surgery for the first time. The results suggest that injection of low doses of 5-Fluorouracil may not be effective. Whilst no evidence was found of an increased risk of serious sight threatening complications, other complications are more common after 5-Fluorouracil injections. None of the trials reported on the participants' perspective of care.

Reviewer's conclusions: Post-operative injections of 5-Fluorouracil are now rarely used as a planned series but are increasingly used on an ad hoc basis. This presumably reflects an aspect of the treatment that is unacceptable to both patients and doctors. None of the trials reported on the participants' perspective of care which constitutes a serious omission for an invasive treatment such as this.