Spearheading the Suprachoroidal Space

In October 2024, BMC Research Notes published a study investigating physicians’ real-world experiences with using triamcinolone acetonide suprachoroidal (SCS-TA) injections for uveitic macular edema (UME) patients. We sat down with two of the study authors – retina surgeon Christopher R. Henry and uveitis specialist Mark S. Dacey – to learn more about the study’s findings, and how they envision SCS-TA being incorporated into the broader ophthalmic landscape.

What were the most surprising findings of your recent study?
 

Christopher Henry: 75 percent of the physicians surveyed felt that it took them only two to five injections to feel comfortable with the procedure. That was probably the most surprising result of the study – that people can learn this technique and feel comfortable with it in such a short period of time.

Mark Dacey: It was also very interesting that 63 percent of the patients expressed no discomfort. That's very encouraging, because this injection is administered more slowly, over about five to 10 seconds, and sometimes it takes several seconds to successfully enter the suprachoroidal space.

What were some of the main factors influencing physicians’ comfort and confidence in adopting SCS-TA injections?
 

Dacey: Training is obviously important for any new procedure. Bausch + Lomb has created individual training sessions that are available on-demand online with a panel of physician trainers. I think those have been quite beneficial.

Henry: Confidence mainly comes down to experience. Physicians who adopt this technique will usually have undergone some type of training before they start doing the procedure. They may have practiced on eye models, learnt how the injector works, things like that. I do think people will be surprised when they do their first injection how easy it is. And I think that that’s where the confidence comes in – if you have a good early experience with this injection, you’re more likely to pick it up and start doing it more often.

Dacey: The greater challenge will be for physicians who have never performed a suprachoroidal injection before. Then, I think individual training sessions, lectures, wet labs etc. will play a role in developing that familiarity.

For first-time users, do you envision any specific challenges with adopting the technique?
 

Dacey: The first thing to point out is that there's two different needles – 900 µm and 1100 µm. Depending on the thickness of the sclera, physicians sometimes have to change to the longer needle to be able to successfully enter the suprachoroidal space. In our study, 91 percent of physicians reported having to change needles at some point. And of course, this has to be discussed with patients in advance of starting the procedure so they're comfortable if that event occurs.

Henry: On a practical level, when I switch from the 900 to the 1100 µm needle, it only takes around 20 to 30 seconds, so you can do this in a very smooth way. I personally don't really feel that it’s a challenge; but it was one of the challenges identified by the study respondents.

Dacey: Entering the suprachoroidal space can sometimes be challenging as well, because you're trying to create a space that doesn't exist. It's a potential space between the sclera and the choroid. Often you have to dimple the conjunctiva to provide enough access. You have to adjust the angle at which the needle is contacting the globe, and physicians often have to put more pressure on the globe than is immediately apparent. That can sometimes introduce some discomfort for the patient. It’s quite different from your standard intravitreal injection.

Henry: The majority of respondents did feel that this injection is slightly more challenging to do than an intravitreal injection, or an intravitreal dexamethasone implant.

Were there any adverse effects of SCS-TA that might not have been observed in earlier clinical trials?
 

Henry: I don't think this came out in the paper, but in the discussions at least one respondent reported that they'd had an injection go intravitreal. This is very uncommon, far less than one percent of cases; it's more likely in eyes that have a thin sclera there's a small chance of the medication going intravitreal. Essentially, if it goes intravitreal it functions just like a Triesence injection. The respondent said the patient was totally fine. Otherwise, there were no really significant side effects – nobody had any cases of retinal detachment, no cases of endophthalmitis, and no cases of suprachoroidal hemorrhage (SCH).

What role do you see suprachoroidal injections playing in the broader landscape of ophthalmic treatments?
 

Dacey: I think it's an exciting new area of exploration for pharmacology. Historically, uveitis studies have been a gateway for new techniques and products for the posterior segment. I think there's significant opportunity for treatment of wet macular degeneration, diabetic macular edema, retinal vein occlusions, and probably a number of other diseases in the future, particularly if anti-VEGFs can be prepared in a manner where they can function long-term in the suprachoroidal space. In the studies and in post-marketing to date, there have been no cases of endophthalmitis, which may point to suprachoroidal injection being a safer technique than intravitreal injection.

Henry: Personally, I see this as a first-line therapy. I think suprachoroidal delivery is at least a direct competitor with intravitreal dexamethasone. There’s good data to support that there's a longer duration of action when compared with intravitreal dexamethasone. If we look at the MAGNOLIA trial, after patients were given an injection at day zero and an injection at week 12, the majority were able to go nine or more months without needing an additional injection.

Dacey: It’s an exciting new development in the treatment of uveitic macular edema, which is the leading cause of vision loss in posterior segment uveitis. In the studies, patients were treated with an initial injection; they had a second one three months later. On average, the macular edema remained resolved for almost an entire year with a very benign side effect profile. This is very exciting for patients who have injection fatigue from periocular and intravitreal steroids injections, and it's a unique approach to bring targeted therapy to the posterior segment. It’s an important advance for uveitis that can subsequently be applied to other retinal diseases as well.

Henry: I think both uveitis doctors and retina doctors need to learn this technique. Obviously now we can deliver steroids into the suprachoroidal space, but in the not-too-distant future we're going to be delivering other medications to this space as well. In the retina world, we're already doing gene therapy for AMD and DME and it's also being used in the ocular oncology space. There are no excuses for retina and uveitis doctors not to learn the technique. It's a very easy technique to perform, and you are going to need it in your armamentarium.