Ab-externo intraluminal stent for prolonged hypotony and choroidal detachment after Preserflo implantation

To describe a case of prolonged hypotony and choroidal detachment following insertion of a Preserflo™ MicroShunt in a patient with primary open-angle glaucoma (POAG).

An 84-year-old Caucasian man with medically uncontrolled POAG developed refractory hypotony and choroidal detachment following a mitomycin C augmented Preserflo MicroShunt (PMS) insertion. Initial medical treatment with Dexamethasone 2 mg/mL and Atropine 1% for the hypotony (4 mmHg) and choroidal detachment was unsuccessful, BCVA decreased from the preoperative 20/28 to 20/60. After 90 days, surgery revision was carried out by inserting a 10-0 nylon monofilament suture through the distal end of the PMS reaching the opposite end of the tube. The free end of the nylon suture was exposed from the conjunctiva in the inferotemporal quadrant close to the fornix to ensure access to the occlusive stent. After one month intraocular pressure (IOP) was 7 mmHg, the choroidal detachment was completely regressed, and best corrected visual acuity (BCVA) increased to 20/28, at that time the exposed part of the stent was trimmed. 6 months after the revision surgery IOP was 14 mmHg, BCVA was 20/25, and the nylon stent was retained side to side inside the PMS lumen.

The management of hypotony and choroidal detachment after a glaucoma drainage device (GDD) implantation is still unstandardized. The ab externo insertion of a nylon suture grants multiple advantages over the other techniques when performed on a PMS tube.