2 Years Outcomes Of A Novel Cilio-Scleral Interposition Device: Enhancing Outflow Without Entering The Anterior Chamber

To assess the effect of a novel cilio-scleral interposition (CID) device inserted ab externo, without subconjunctival filtration nor anterior chamber (AC) infraction, on the IOP and postoperative glaucoma medications (meds) rate of patients with primary open-angle glaucoma (POAG).

First-in-human clinical study conducted in S.V. Malayan eye Centre, Yerevan, Armenia from December 2020 to May 2021

The 25% hydrophilic acrylic, 6 by 4 mm, 200 µm thick, CID implant was inserted 2 mm behind the limbus through 2 scleral incisions, separating the sclera and ciliary body without entering the AC. Scleral incisions are watertight closed after implant positioning.

Group 1 received 1 implant and group 2 received 2 implants sutured together. Inclusion criteria included POAG Shaffer 3 and 4 with medically uncontrolled IOP, naive from any prior glaucoma incisional surgery, glaucoma standalone surgery. No washout was performed. Prostaglandins were mandatory per protocol for 30d post-operatively. IOP, concomitant pharmacological treatments and other clinical and safety parameters were collected up to 24 M. Follow up is expected for at least 3 years.

42 patients (62 ± 9 yrs, 23M 19F) were included.

In group 1, baseline IOP was 23.7 ± 2.5 mmHg with 2.0 ± 0.7 meds, 15.6 ± 6.3 mmHg w 0.2 ± 0.4 meds at M6 (n=19), 15.5 ± 2.4 mmHg w 0.2 ± 0.5 meds at M12 (n=17),  15.6 ± 2.6 mmHg w 0.5 ± 0.9 meds at M24 (n=14) showing IOP decrease of 34%, 34% and 33%, and meds decrease of 89%, 91% and 74% at each timepoint.

In group 2, baseline IOP was 25.8±4.5 mmHg w 1.6 ± 0.6 meds, 17.0 ± 2.8 mmHg w 0.1 ± 0.3 meds at M6 (n=16), 17.2 ± 4.8 mmHg w 0.2 ± 0.4 meds at M12 (n=13) showing IOP decrease of 33% and 33%, and meds decrease of 96% and 91% at each timepoint.

At 24M, no bleb, implant displacement, nor encapsulation was observed. No patient had to undergo additional adjunctive treatment nor surgery up to 24M.

These results suggest that the CID device can effectively lower IOP and postoperative medication rate, without penetrating the AC and with no significant adverse event or complication. This device could represent a safe and effective treatment option for patients with POAG and could reduce the clinical and economic burden associated with glaucoma medications.