Experts Offer Guidance on Suprachoroidal Space Injections, the Newest Frontier in Retinal Drug Delivery

Suprachoroidal space (SCS) injection offers unique benefits that could broaden treatment options for patients with retinal conditions, according to first-ever guidelines laid out in a recent study led by a Houston Methodist Hospital ophthalmologist.

The guidelines, produced by a panel of experts and published in the journal Retina, support and promote the standardization of SCS injection, the innovative approach for targeted drug delivery that has been under exploration for several years but is still relatively new in clinical practice. SCS represents an alternative drug delivery site to the traditional intravitreal injection.

"We wanted to provide ophthalmologists with a detailed roadmap for safely and effectively delivering medications into the eye's suprachoroidal space," said Dr. Charles Wykoff, a professor of Clinical Ophthalmology at Houston Methodist and the study's first author. "It's a new skill set for many physicians, but one with a lot of potential for expansion in the future."

The minimally invasive technique is appealing because it can precisely deliver medication and reduce the risk of adverse events. It is performed in an office setting.

The suprachoroidal space, situated between the choroid and sclera in the wall of the eye, is a key site in uveoscleral outflow, notes Dr. Wykoff, also a retinal disease specialist at Retina Consultants of Texas.

"This choroid-adjacent potential space expands with the introduction of fluid and serves as a drainage path from the front to the back of the eye, contributing to the normal maintenance of intraocular pressure," said Dr. Wykoff.

While the procedure shares some similarities with more widely used intravitreal injections — where medication is delivered directly into the eye's vitreous cavity — it also offers some advantages.

For instance, whereas intravitreal injections can cause floaters and other visual disturbances, medications injected into the suprachoroidal space are not visible to patients.

Additionally, preclinical studies on distribution and durability have reflected favorably on SCS injection techniques.

Animal eye models showed high levels of small molecule injectates in posterior tissues with some drugs persisting in the retinal pigment epithelium-choroid-sclera and retinas of rabbit eyes up to six months, supporting the potential for prolonged drug bioavailability.

"It's not necessarily a more effective space to do an injection, it's just a different space, with a side effect profile that may be more favorable for certain therapeutics in some circumstances," said Dr. Wykoff.

To inform the new guidelines, the panel reviewed current published evidence and clinical experience to define points of consensus including best practices in patient preparation, pre- and peri-injection management, SCS-specific injection techniques and post-injection management and follow-up.

The guidelines conclude that current clinical evidence and physician experience supports SCS injection as a safe and effective method for delivering retinal and choroidal therapeutics.

Currently, the only FDA-approved medication administered through this route is XIPERE (triamcinolone acetonide injectable suspension produced by Bausch + Lomb), a steroid used to treat macular edema associated with noninfectious uveitis.

"It's still a relatively niche product at the moment, but it has the potential to be used in the treatment of more retinal pathologies," Dr. Wykoff explained. "Many companies are studying the space for the delivery of novel therapeutics."

Clinical trials are underway for a wide range of treatments utilizing the suprachoroidal space, including gene therapies and slow-release drugs for other retinal conditions.

As research continues and more drugs become available, Dr. Wykoff and colleagues will follow the developments carefully to help physicians navigate this emerging frontier with confidence.