Comparison of two techniques used in routine care for the treatment of inflammatory macular oedema, subconjunctival triamcinolone injection and intravitreal dexamethasone implant: medical and economic importance of this randomized controlled trial

Abstract

Background: Whether they are injected peri- or intraocularly, corticosteroids are still essential tools in the therapeutic arsenal for treating inflammatory macular oedema. A few years ago, however, only triamcinolone acetonide was available to ophthalmologists. While this compound was initially developed for rheumatological or dermatological use, it has been increasingly deployed in ophthalmology, despite still being off-label. In 2011, the system for delivery of dexamethasone from a biodegradable, injectable implant into the vitreous cavity obtained approval for use in inflammatory macular oedema. While the efficacy and safety of triamcinolone in macular oedema, including inflammatory oedema, have already been studied, there are currently no publications on subconjunctival triamcinolone injections, which are simple, effective and well tolerated. To date, the dexamethasone 700 μg implant has been authorized for the treatment of noninfectious intermediate and posterior uveitis, but there have been no studies to evaluate the efficacy and safety of the different peri- and intraocular strategies, including the treatment of inflammatory macular oedema.

Methods: This protocol is therefore designed to compare the efficacy and safety of peri- and intraocular corticosteroid injections in the treatment of inflammatory macular oedema. In this ongoing study, 142 patients will be included, and the oedematous eye will be randomised to treatment with either subconjunctival triamcinolone injection or an intravitreal implant containing 700 μg dexamethasone. Follow-up is planned for 6 months with monthly visits. Each visit will include visual acuity measurement, a slit lamp examination, fundoscopy, intraocular pressure measurement, laser flare measurement (if available) and spectral domain optical coherence tomography.

Discussion: The results of this trial will have a real impact on public health if it is shown that a Kenacort retard® (i.e. triamcinolone) injection costing just €2.84 and performed in the physician's office (with no additional overhead costs) is at least as effective as the dexamethasone 700 μg implant (Ozurdex®; costing approximately €960 with the injection performed in a dedicated room), with no increased side effects.

Trial registration: ClinicalTrials.gov, NCT02556424. Registered on 22 September 2015.

Keywords: Corticoids; Intraocular injection; Macular oedema; Medical cost–benefit analyses; Periocular injection.

Fig. 1

Subconjunctival triamcinolone crystals (from Turpin et al. [11])

Fig. 2

An intravitreal dexamethasone 700 μg implant (from Turpin et al. [11])

Fig. 3

Flowchart: overview of the enrolment and follow-up of study participants. D day, M month

Fig. 4

Intravitreal injection (from Turpin et al. [11])