Using targeted drug delivery to suprachoroidal space to treat macular edema

Reviewed by Steven Yeh, MD

Triamcinolone acetonide injectable suspension (Xipere, Bausch + Lomb) was launched recently as the first and only therapy approved by the FDA for use in the suprachoroidal space to treat the macular edema associated with uveitis.

This method of administration facilitates targeted delivery of the medication to the retina and choroid.

“This injection procedure is a more nuanced technique compared with intravitreal injections and relies on delivering the medication to the suprachoroidal space, which is a low-resistance system,” said Steven Yeh, MD, a professor of ophthalmology and director of Retinal Disease and Uveitis at the Stanley M. Truhlsen Eye Institute at the University of Nebraska Medical Center in Omaha, Nebraska.

About 47% of patients with macular edema associated with noninfectious uveitis have a 3-line or greater improvement in visual acuity as a result of injection of triamcinolone acetonide injectable suspension, he reported.

Drug delivery pearls

Yeh emphasized the importance of discussing with patients that this injection technique is new.

Importantly, patient selection is paramount, in that this technique of suprachoroidal injection is performed in patients with noninfectious uveitis with macular edema who likely will benefit from increased vision and reduced macular edema.

Yeh said he prefers to use subconjunctival lidocaine, although other physicians favor a topical anesthetic.

After applying the local anesthetic and antiseptic, such as betadine, he uses a 900-microneedle held perpendicular to the ocular surface to administer the drug to the suprachoroidal space.

“This allows me to maximize the short length of the needle while delivering the drug reliably into the suprachoroidal space,” he explained.

The microneedle has a circular area that will create a small dimple in the conjunctiva, which allows the tissue to displace as the needle enters the suprachoroidal space. Dr. Yeh described that as the plunger of the micro-needle is depressed gently, he can feel the lessening of resistance as the medications enters the suprachoroidal space.

He also pointed out that the scleral has greater resistance and as a result this resistance can be felt if the needle is not positioned correctly within the suprachoroidal space.

“I deliver the medication with a very steady, slow, deliberate pace over about 5 seconds in contrast to a rapid injection,” he advised, because patients may feel the expansion of the suprachoroidal space and pressure.

The Bausch & Lomb training accurately reproduces what the clinician should feel as Xipere is being administered, Dr. Yeh said.

Safety considerations

Injection of the drug into the suprachoroidal space can be associated with elevated intraocular pressure in about 12% to 14% of patients or development of cataract in about 6% to 7% of treated and sham-treated patients in the Peachtree study.¹

Development of endophthalmitis is also a possible adverse event, with an incidence rate of about 1 case in 2,000 patients who receive intravitreal injections.

Patient discomfort is possible when the drug is injected too rapidly or when the anesthesia is inadequate.

Physicians should also rule out the possibility of active infectious uveitis because of the potential for exacerbation of the disease with steroids.

“Xipere is an advance in drug delivery for the treatment of macular edema associated with noninfectious uveitis,” Yeh concluded. “I am excited about the possibility of where this drug delivery platform will go, both for uveitis patients as well as other patients with retinal conditions for which this platform is currently being studies.”

Steven Yeh, MD

E: Syeh@unmc.edu

Yeh is a consultant to Bausch & Lomb.

Reference

1 Yeh S, Khurana RN, Shah M, et al., for the PEACHTREE Study Investigators. Efficacy and safety of suprachoroidal CLS-TA for macular edema secondary to noninfectious uveitis phase 3 randomized trial. Ophthalmology 2020;127:948-55; published January 10, 2020, DOI: https://doi.org/10.1016/j.ophtha.2020.01.006