18 Months Outcomes And Ubm Imaging Of A Cilioscleral Interposition Device (Cid Sv22) For Surgical Treatment Of Angle Closure Glaucoma

We propose a conservative surgical treatment in angle closure glaucoma, leaving the lens in place and not entering the anterior chamber (AC). A Cilioscleral Interposition Device (CID SV22) is inserted ab externo over the ciliary body to increase uveoscleral outflow and lower the IOP. Since very little information can be found in the literature on UBM examination of supraciliary devices, we performed, in addition to ordinary clinical assessment (visual acuity, gonioscopy, visual field, intra ocular pressure (IOP), medications) an ultrasound examination by means of UBM to analyse the condition of the device at every postoperative visit, looking for its position vs adjacent structures, bio integration, uveoscleral outflow, and safety.

Prospective nonrandomised non controlled clinical study conducted in S.V. Malayan eye Centre, Yerevan, Armenia from May to December 2022, comparing CID SV22 performance and safety in POAG and PACG patients in standalone surgery.

CID SV22 is a Cilioscleral Interposition Device made of 26% hydrophilic acrylic, generally flat and trapezoidal in shape, measuring 6 by 3.4 mm, 400 µm thick.

The results introduced here only relate about the PACG group.

29 PACG phakic eyes (Shaffer 1-2) with uncontrolled IOP, some with peripheral iridotomy (PI), were included. Except PI, no intra ocular surgery was performed prior to implantation. 7/29 eyes presented with a plateau iris.

2 radial incisions, conjunctiva and sclera, resp. 1,5 and 3 mm long, is made in the superior quadrant 2mm from the limbus, separated by 8mm. A cohesive OVD is injected through one incision to create some space between the sclera and the ciliary body. A CID SV22 is slid in place with a vitreous retinal forceps, then incisions are sutured watertight.

AC and lens are untouched.

IOP, concomitant pharmacological treatments and other clinical and safety parameters were collected at D1, D7, M1, M3, M6, M12, M18.

Preop IOP (ITT n=29) was 23.5 mmHg w 1.7 meds and 15.1 mmHg w 0.3 meds at M18  showing IOP/meds decrease of resp. 37/85% at M18 (comparable to POAG group)

BCVA VF CCT ECD were controlled stable with time. Safety was very good with almost no adverse device effect reported, only one localised cyclodialysis cleft without clinical consequence

UBM confirmed the CID was always above ciliary body and most often close to the angle. Some inflammation signs at D1, self-resolving and not confirmed with slit-lamp. AC depth, angle shape, implant location remain stable. No ciliary body or trabecular meshwork movement, no scleral thinning, no iris erosion. Biointegration was excellent. Supra ciliary effusion-filtration of aqueous detected in 25% of cases

This innovative surgical approach to treat angle closure glaucoma, including plateau iris, does not necessitate to remove the lens and/or to create subconjunctival filtration. 

UBM examinations confirm a satisfactory placement and anatomical behaviour of the device. The absence of penetration in the AC is another element of increased safety.

At 18 months the visual functions are preserved, and the IOP reduction of 37% with 0,3 med goes with patients improved quality of life.

Longer follow-up is required to confirm these first positive outcomes, and additional research work is needed to explain all IOP lowering mechanisms.