Targeting the Supraciliary Space in Glaucoma Treatment

The treatment of glaucoma is continuing to undergo a revolution. The last two decades have seen the glaucoma specialist’s armamentarium grow exponentially (especially in the surgical realm) – driven mainly by the advent of less invasive surgical options, encompassing procedures and devices such as microinvasive glaucoma surgery (MIGS) and minimally invasive bleb surgery (MIBS).

One particularly promising glaucoma treatment area concerns the supraciliary space – located anteriorly between the outer surface of the ciliary body and the internal surface of the sclera – where there is the potential to yield a powerful IOP lowering effect. Just as importantly, the supraciliary space allows for the introduction of complementary treatment modalities. Patients are living longer and it is not unreasonable to expect that those with particularly severe disease may need multiple interventions within their lifetime. The glaucoma specialist is therefore keen to avoid choosing modalities that may preclude other options “down the road.”

The supraciliary space is somewhat underused compared with other options, such as the many options targeting the conventional trabecular pathway and the multiple bleb-forming subconjunctival approaches. Some reasons for this may include an inability to predictably control cleft behaviour and the very fact that we are yet to see an option for this space which has truly stood the test of time. Most well documented, however, are the risks associated with implanting a physical device within the anterior chamber, which can give rise to endothelial cell decompensation.

In recent years, Alcon made a valiant attempt at targeting the supraciliary space with the CyPass Microstent, but the device was later voluntarily withdrawn from the market. It was found that there was a clear late-stage degradation of endothelial cells – a direct consequence of trauma caused by the presence of the device within the anterior chamber.

Since 2017, Ciliatech SAS has been developing a potential solution in this area, the Cilioscleral Interpositioning Device (CID). The CID targets the supraciliary space via an ab-externo implantation without the need to enter the anterior chamber. Our approach should eliminate degradation of corneal endothelial cells – and will avoid other potential effects associated with operating inside the anterior chamber. To date, the first-in-human clinical studies have already started reporting (with follow-up now reaching up to three years in the first trials) and an extensive clinical trial program is underway to continue gathering evidence for the device. There are currently four ongoing clinical studies, with a fifth planned to start in late 2024 or early 2025.

However our CID development plays out, the hope is that glaucoma surgeons of the future will be armed with more choices for the important supraciliary space, which will give them the option to treat the disease through this complementary anatomical pathway – potentially giving patients an even longer time horizon to avoid losing functional sight. If we can crack the supraciliary space, we can effectively open another important treatment pathway for glaucoma surgeons and patients. So, we encourage you to watch this (supraciliary) space!