The Use of Suprachoroidal Triamcinolone Acetonide to Treat Macular Edema in Retinal Vein Occlusion

This prospective non-randomized open-label interventional study aimed to evaluate feasibility in regard to potential efficacy and safety of triamcinolone acetonide (TA) injected in the suprachoroidal space (SCS) as a promising therapeutic route that provides a better bioavailability, longer sustained duration of action, and thus improved patients' compliance for the treatment of macular edema due to retinal vein occlusion (RVO).

Management of Macular Edema (ME) associated with Retinal Vein Occlusion (RVO) still poses a therapeutic challenge taking into account its complicated etiopathogenesis. Despite improved visual and anatomical outcomes achieved by intravitreal injections of antiangiogenics and steroids, these treatments are still associated with non-responders, tachyphylaxis, rebound phenomenon, high re-injection, and adverse events rates, which underscore the importance of addressing new approaches to formulate treatment strategies.

Delivery of therapeutic agents into the suprachoroidal space (SCS) provides a novel alternative approach that has theoretical appeal, as it dominantly targets chorioretinal tissues with the posterior and circumferential spread of the drug administered while relatively sparing the unaffected anterior segment of the eye and the vitreous chamber, thus minimizing risks associated with off-target effects, which potentiates safety. This was well translated in preclinical and clinical studies through microinjector, which has been shown to provide a safe, minimally invasive, and reliable method of targeting SCS. In addition, sustained duration and favorable pharmacokinetics have been observed for small molecule suspensions including Triamcinolone Acetonide (TA), with the potential to reduce treatment burden.

Eligibility Criteria:
Inclusion Criteria:

1. Male or nonpregnant female patients \>18 years of age.
2. Has a clinical diagnosis of Retinal Vein Occlusion (RVO) in the study eye.
3. Best-Corrected Visual Acuity (BCVA) in Early Treatment Diabetic Retinopathy Study (ETDRS) letter score ≥ 20 (20/400 Snellen equivalent), and ≤75 in the study eye (20/32 Snellen equivalent).
4. Central Subfield Thickness (CST) ≥310 microns measured by Spectral Domain Optical Coherence Tomography (SD-OCT) in the study eye.

Exclusion Criteria:

1. Intravitreal (IVT) injection of anti-VEGF: Bevacizumab (Avastin; Genentech, South San Francisco, CA, USA/Roche, Basel, Switzerland) or ranibizumab (Lucentis; Genentech Inc., South San Francisco, CA, USA) within 1 month and aflibercept (Eylea®; Regeneron Pharmaceuticals Inc., Tarrytown, NY, USA, and Bayer HealthCare Pharmaceuticals, Berlin, Germany) within 2 months in the study eye.
2. Intraocular or periocular corticosteroid injection within 3 months, dexamethasone implant (Ozurdex, Allergan, Dublin, Ireland) within 6 months, Retisert (Bausch and Lomb, Bridge water, NJ) within 1 year, or fluocinolone acetonide implant (Iluvien, Alimera Sciences, Alpharetta, GA) within 3 years in the study eye.
3. Macular laser photocoagulation treatment in the study eye.
4. Topical ophthalmic nonsteroidal anti-inflammatory drugs in the study eye within a month.
5. Any significant media opacity that could hinder the evaluation of the retina or ocular condition causing decreased vision other than RVO.
6. IOP \>22 mm Hg, or history of steroid-induced ocular hypertension; uncontrolled glaucoma.
7. Past vitreoretinal or glaucoma surgery in the study eye.
8. Uncontrolled systemic disease that could hinder follow-up, immunodeficiency, or any other systemic contraindication for steroids.