[Preservative-free triamcinolone versus purified triamcinolone preparations]

Intravitreal injections of triamcinolone are not only an important therapeutic tool for a variety of vitreo-retinal disorders, but can also be employed for visualisation of the vitreous during pars plana vitrectomy. Triesence® is a preservative-free triamcinolone suspension that has been approved for visualisation during vitrectomy via intravitreal administration and as intravitreal therapy for certain rare ocular diseases. However, the differences between Triesence® and purified (and thus also preservative-free) triamcinolones such as Volon A® or Kenalog® are not well specified, although the manufacturer of Triesence® advertises the product as "specifically formulated for the eye".

The publicly available FDA application material and information provided by the manufacturer for Triesence®, Kenalog® and Volon A® were analysed with respect to the differences between Triesence® and older triamcinolone preparations.

According to the publicly available FDA documents the approval of Triesence mainly was based on studies that have been conducted with the older triamcinolone preparations Kenalog® or purified Volon A®. Apart from the absence of preservative the differences between Triesence® and the "older" triamcinolone preparation seem marginal. Published experimental or clinical studies in respect to the possible advantages of Triesence® compared to Kenalog® or Volon A® are lacking. Triesence® has been approved for sympathetic ophthalmia, temporal arteriitis, uveitis unresponsive to topical corticosteroids and for enhancing tissue visualisation during vitrectomy. Recently, the manufacturer of Kenalog® added a warning label ("not for intraocular use") on each vial of Kenalog®. The motifs for this re-labelling of Kenalog® remain unclear.

Apart from the intraoperative use during vitrectomy Triesence® has only been approved for sympathetic ophthalmia, temporal arteriitis, and ocular conditions unresponsive to topical steroids. Consequently, the use of Triesence® like the older triamcinolone preparations (Kenalog® or Volon A®) for diabetic macular oedema, for Irivine-Gass syndrome, for neovascular AMD or after retinal vein occlusion is off-label.