PreserFlo MicroShunt Tube Embedded in the Iris: Successful Treatment Using Argon and Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) Lasers and Laser Iridotomy for Recurrence Prevention

The PreserFlo MicroShunt (PMS) (Santen Pharmaceutical, Co., Ltd., Osaka, Japan) procedure is classified as minimally invasive glaucoma surgery (MIGS) and is a type of tube shunt surgery. Tube occlusion in PMS is a rare but significant complication that requires intervention unless caused by temporary thrombi. This report describes a rare case where a PMS tube became completely embedded in the iris, and the condition was successfully managed with the combined use of argon and neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers. A 54-year-old woman with pigmentary glaucoma in her right eye underwent trabeculectomy but failed to achieve adequate intraocular pressure (IOP) control. PMS implantation was performed approximately five months after the initial surgery. Seven months post-implantation, the entire PMS tube became embedded in the iris, leading to IOP elevation. Argon and Nd:YAG lasers were used to relieve the occlusion, followed by laser iridotomy around the tube tip to prevent re-occlusion. The IOP was well-controlled immediately after the laser procedure and remained stable for three months postoperatively, with no recurrence of occlusion or corneal endothelial damage. The combined use of argon and Nd:YAG lasers appears to be a promising and safe treatment option for managing iris-related PMS occlusion and preventing recurrence.