The field of retina continues to rapidly advance and we, as retinal physicians, continue to evolve our practice to incorporate new innovations. Intravitreal injections have been the mainstay of in-office drug delivery, helping to revolutionize the treatment of exudative pathologies with the introduction of anti-VEGF agents and, more recently, with the entry of a bispecific anti-VEGF/Ang2 agent. However, the route of in-office administration has largely stayed the same with each incremental advancement over the past 2 decades. The recent approval of Xipere (Bausch + Lomb), validating suprachoroidal drug delivery and making it a clinical reality, may well be seen as an inflection point in the future: we now have an alternative route of administration, which targets posterior structures with limited anterior-segment exposure.

This special edition of Retinal Physician, supported by Bausch + Lomb, is intended to explore the potential benefits of the suprachoroidal route, the experience with injections into the suprachoroidal space (SCS) that brought us Xipere, and future avenues being explored.

Noninfectious uveitic macular edema is the indication that has ushered in suprachoroidal injections from trial to clinic. This issue includes a feature describing the role and potential benefits of SCS steroid delivery in this setting.

Because the injection technique and delivery site differ from traditional intravitreal injections, this issue also offers a review of the technique, as well as the safety and reliability profile of SCS injections from the collective experience across numerous trials for a variety of retinal disorders, with an overview of pipeline SCS agents. Further insights into the anatomy and biomechanics of suprachoroidal delivery via microneedle injection are also presented, as well as 2 different modalities of accessing the SCS, via microneedle vs tunneled suprachoroidal catheter.

One of the potential applications of SCS injections garnering interest is gene therapy. Because our current approach to gene therapy employs viral vectors to transduce target tissue and generate therapeutic product, a key consideration in delivering these agents is circumventing or mitigating the immune reaction and subsequent inflammation elicited by viral vectors as a class. Although recent strategies include steroid prophylaxis for intravitreal administration and delivery to the immune-privileged subretinal space via a surgical route, suprachoroidal injection is uniquely positioned as an in-office treatment with a potentially reduced inflammatory profile. The application of SCS delivery in gene therapy and the associated current trials in diabetic retinopathy and exudative AMD are reviewed in this issue.

Another condition that might potentially benefit from a suprachoroidal approach is the treatment of melanoma. While radiation is an effective treatment, it also comes with many negative sequelae. A feature in this issue addresses light-activated suprachoroidal therapy for the first line treatment of indeterminate lesions and small choroidal melanoma, reviewing the mechanism of action and suprachoroidal delivery of infrared dye-conjugated virus-like drug conjugates, and their potential to treat choroidal melanoma with a reduced side-effect profile.

Together, these articles aim to familiarize retinal physicians with suprachoroidal drug delivery. We hope you find them to be informative and beneficial to your practice. RP

Mark Barakat, MD, is a retina specialist and the director of research at Retinal Consultants of Arizona in Phoenix, Arizona. Dr. Barakat reports consultancy to Bausch + Lomb, Clearside Biomedical, Adverum Biotechnologies, Regenxbio, Genentech, Novartis, and Regeneron. Reach him at mark.barakat@gmail.com.