Suprachoroidal triamcinolone acetonide for the treatment of macular edema associated with retinal vein occlusion: a pilot study

BACKGROUND: Suprachoroidal Drug Delivery has emerged in recent years as a novel promising approach, which may help address the clinical unmet needs in the management of Retinal Vein Occlusion (RVO) associated Macular Edema (ME). In this study, we aim to evaluate the feasibility in regard of the potential efficacy and safety of suprachoroidal injection of Triamcinolone Acetonide (TA) using a microinjector as a mono-treatment of ME due to RVO. METHODS: This trial included 16 eyes of 16 patients with RVO associated ME presenting to the department of ophthalmology, Al Mouwasat university hospital, Syria. 4 mg of preserved TA was injected suprachoroidally 4 mm away from the inferotemporal limbus using a patient-customized microinjector. After injection, patients were followed after 1 week then monthly for 3 months. Primary outcome measures included the percentage of participants with best-corrected visual acuity (BCVA) gain≥15 letters and increased intraocular pressure (IOP) ≥ 20 mmHg in months 1,2, and 3, secondary measures included mean change from baseline BCVA, central subfield thickness (CST), and IOP through each of the follow-up points in addition to other measures. RESULTS: After injection, BCVA gain≥15 letters occurred in 68.7, 62.5, 50, 50% of patients at week 1 and through months 1,2 and 3 respectively, the mean BCVA improved significantly by 16.4, 16, 14.4, and 11.9 letters (p-value< 0.0005) at week 1 and months 1,2 and 3 respectively. This visual gain was associated with a significant reduction of CST by 290.94 ± 181.76 (week-1) (p-value< 0.0005), 274.31 ± 184.60 (month-1) (p-value< 0.0005), 183.50 ± 165.61 (month-2) (p-value = 0.006) and 137,75 ± 156.25 μm (month-3) (p-value = 0.038). We reported one case of increased IOP ≥ 20 mmHg in the first month that decreased in the second month. The mean change of IOP readings was not statistically significant, with an increase ranging from 0.75 mmHg after the first week (p-value = 0.09) and 0.5 mmHg after 3 months (p-value = 0.72). CONCLUSION: This study suggests that suprachoroidal TA could be well tolerated and efficacious as a mono-treatment of RVO associated ME. Future clinical trials are required to confirm its longer-term safety and efficacy and to compare this efficacy with the other therapeutic options. TRIAL REGISTRATION: This study was retrospectively registered at clinicaltrials.gov (ID: NCT05038072) on 08/09/2021. This article was published as a preprint on 22/06/2022. 10.21203/rs.3.rs-1701105/v1.