[Microsurgical trimming of the CyPass stent : Surgical procedure of the Neubrandenburg Eye Clinic. Video article].

OBJECTIVE OF SURGERY

The indications for CyPass trimming are based on the standard protocol for endothelial protection of the Department of Ophthalmology at the Dietrich Bonhoeffer Hospital Neubrandenburg. The CyPass stent should be shortened to a maximum reach up to the scleral spur.

INDICATIONS

The indications for CyPass trimming are based on two main criteria: the position of the CyPass in relation to the structures of the anterior chamber angle and the presence of corneal endothelial cell loss.

CONTRAINDICATIONS

There are no contraindications.

SURGICAL TECHNIQUE

The operation shown in the video available online is performed with the patient under local anesthesia. The incisions are created individually and depend on the position of the CyPass stent. Through a 1.2 mm corneal paracentesis opposite to the stent, the anterior chamber is filled with a cohesive viscoelastic material and the stent is stabilized with a 20-gauge vitreous forceps and then cut with 20-gauge bent vitreous scissors through another 1.4-1.8 mm paracentesis, 3-4 h away from the stent visualized by gonioscopy. In some cases, surgical goniosynechiolysis in the area of the stent is required. The anterior end of the stent is cut as deep as possible. After aspiration of the viscoelastic material and possibly blood, the anterior chamber is toned with balanced salt solution (BSS) and the paracenteses are hydrated. Corneal suturing is not necessary.

RESULTS

Up to November 2019 65 CyPass stents in 64 eyes have been trimmed using this method. Iridodialysis occurred in 1 eye, in 12 eyes slight self-limiting bleeding and in 2 eyes an iris defect.

CONCLUSION

The procedure shown enables a safe microsurgical shortening of the CyPass stent with few complications. The risk of intraoperative expulsive bleeding or postoperative fistulation is markedly reduced.