Comparison of subconjunctival TRIamcinolone acetonide injection and intravitreal dexamethasone (OZurdex) injection for uveitic and postoperative macular oedema: the TRIOZ study.

Aims: To compare effectiveness of subconjunctival triamcinolone acetonide injections and intravitreal injections of dexamethasone 700 µg implants in reducing central macular thickness (CMT) in uveitic and postoperative macular oedema (ME).

Methods: We conducted an open-label, French multicentre randomised comparative trial with a logarithmic CMT non-inferiority margin set at 0.06. Patients were adults with non-infectious inflammatory ME, without any contraindication to the treatments. They were randomised 1:1 to receive either triamcinolone or dexamethasone. The primary endpoint was the difference in CMT among treated eyes between baseline and 2 months, measured with spectral-domain optical coherence tomography. Secondary outcomes included visual acuity, laser flare, vitreous haze, duration of action, tolerance to injections and adverse events.

Results: Between January 2016 and January 2020, 106 patients were enrolled (54 in the triamcinolone group and 52 in the dexamethasone group). Subconjunctival triamcinolone injections seemed to be non-inferior to intravitreal dexamethasone injections, especially at month 3 (and nearly at month 1). Nevertheless, we could not demonstrate it, with a treatment effect at month 2 of 0.05 (0.01 ; 0.09) (p value=0.001). This was corroborated by post hoc analyses in the postoperative subgroup, for whom the non-inferiority was nearly demonstrated at month 2 with a treatment effect of 0.02 (-0.03 ; 0.08) (p=0.37). There was no significant difference in the occurrence of adverse effects.

Conclusion: We could not demonstrate the non-inferiority of triamcinolone injections at month 2. Nevertheless, they showed some efficacity, particularly in treating postoperative ME, being as safe as dexamethasone injections, without any loss of chance if a therapeutic switch is necessary.