Suprachoroidal injection of triamcinolone acetonide as adjuvant to surgical treatment of epiretinal membrane

Background: To analyse the effect of suprachoroidal injection (SChI) of triamcinolone acetonide (TA) on macular thickness (CRT), ectopic inner foveal layer thickness (EIFL-T) and best corrected visual acuity (BCVA) in pseudophakic patients undergoing vitrectomy for epiretinal membrane (iERM) compared to intravitreal injection of TA (IVTA). Methods: Prospective matched comparison of patients undergoing vitrectomy for Govetto stage 3 and 4 iERM. 25 eyes receiving IVTA (G-1) were compared to 23 eyes receiving SChI-TA (G-2) during vitrectomy. Primary outcome was change in BCVA, CRT, EIFL-T before surgery and 1, 3 and 6 months after surgery. Secondary outcome was the incidence of cystoid macular edema (CME). Results: Six months after surgery, G2 had a greater mean reduction in CRT (−222 µm vs −131 µm) and EIFL-T (−200 µm vs −104 µm) than G1. BCVA improved more in G2 than in G1 (p = 0.02). Foveal depression reformed in 43% of cases in G-2 and 16% of cases in G-1. Incidence of postoperative CME was 16% in G-1 and 4.3% in G-2. Conclusions: During vitrectomy for iERM, SChI-TA was more effective than IVTA in reducing CRT and EIFL-T and improving BCVA. SChI-TA was effective in preventing postoperative CME. SChI-TA treatment was safe and reproducible and did not affect postoperative IOP. Trial registration NP6289—June 18th, 2024 (retrospectively registered).