Healey and Crowston, in the September issue of BJO,¹ describe a novel and ingenious study using trypan blue to stain antiproliferative agents used during trabeculectomy surgery and trabeculectomy bleb needling. Trypan blue is commercially available as Vision Blue (Dorc, Zuidland, Netherlands). It is widely used in cataract surgery to stain the anterior capsule, and in vitreoretinal surgery to improve the visibility of preretinal membranes and is therefore readily available in most eye theatres.

They describe a clinical safety and efficacy trial backed up by laboratory based studies of colouring mitomycin C or 5-fluorouracil with the vital dye trypan blue 0.1%. Addition of trypan blue in vitro had no effect on cell death rates in controls or on mitomycin C and 5-fluorouracil treated cells. In vivo, there was no difference in outcome in a series of eyes undergoing trabeculectomy surgery with trypan blue stained antiproliferative agent compared to controls. This technique has the potential to be useful both in research to compare outcomes of surgery as well as in clinical practice by enhancing safety in the use of antiproliferative agents and improving surgical technique.

Trabeculectomy is the surgical procedure of choice in most countries for treatment of chronic open angle glaucoma. Since the first description in 1968 by Cairns² the operation has survived challenges from procedures such as laser trabeculoplasty,³ holmium laser sclerostomy,⁴ artificial drainage devices^5–7 and, more recently, …