The suprachoroidal space (SCS) is the potential space between the sclera and choroid. Drugs delivered through SCS can bypass the sclera, avoiding clearance by conjunctival and scleral blood vessels and lymphatic circulation, so that more drugs can reach the disease tissues such as choroid and retina. SCS drug delivery does not disrupt the ocular integrity, is safer than the intravitreal drug injection and more effective than trans-scleral drug delivery. In addition, SCS delivery only needs a very small volume of drug, which makes it possible to be carried out in multiple parts of the sclera, and the specific disease area can be more precisely targeted. SCS drug delivery is suitable for the treatment of choroidal and retinal diseases. However, currently SCS drug delivery is still a novel field and many aspects need to be more in-depth studied, including its safety, delivery methods, drug formulation and effectiveness.
The suprachoroidal space is a potential space between the sclera and choroid. Suprachoroidal spacedrug delivery is becoming an applicable method to the ocular posterior segment diseases. Because it targets the choroid, retinal pigment epithelium and retina with high bioavailability and safety, while maintaining low levels elsewhere in the eye. In recent years, new discoveries has been carried out in different areas of interest, such as drug delivery methods, pharmacokinetics and clinical trials. Clinical trials with suprachoroidal space injection of triamcinolone acetonide are executed with promising findings for patients with noninfectious uveitis and diabetic macular edema. Suprachoroidal space triamcinolone acetonide injectable suspension is the first and currently the only agent specifically approved for uveitic macular edema by Food and Drug Administration. Nowadays, many clinical trails with suprachoroidal space drug delivery have been explored, although there are still many risks and uncertainties. With the development of technology in the future, suprachoroidal space drug delivery appears to be a promising treatment modality for ocular posterior segment diseases.