A Case Report of the Combined Use of Neodymium-Doped Yttrium Aluminum Garnet and Argon Lasers in Treating Luminal Obstruction by Iris Tissue in a Preserflo MicroShunt Implant

We aim to report a case of iris tissue obstructing the lumen following rotation of the Preserflo MicroShunt (PMS) and subsequent laser therapy, which restored the shunt's function. A 65-year-old man with bilateral primary open-angle glaucoma (right eye: early stage, left eye: severe stage) had suboptimal intraocular pressure (IOP) control in his left eye despite maximal medical therapy. Hence, with an uneventful operative course, PMS implantation augmented with mitomycin C (0.04%) was performed in the left eye. However, one week post-surgery, his IOP spiked to 30 mmHg, and anterior segment examination revealed that the adjacent iris tissue obstructed the lumen of the PMS. Neodymium-doped yttrium aluminum garnet and argon lasers were used to unclog the lumen and retract the iris tissue from the PMS. Following the procedures, the lumen was free from the iris tissue, and the IOP was normalized to 10 mmHg. His target IOP was achieved without any antiglaucoma medication to date. In contrast to surgical repositioning or revision, laser therapy can be done in an outpatient setting. It is an effective and less invasive method of removing or avoiding iris tissue from obstructing the lumen of the PMS. Laser therapy offers an effective and safe option for managing PMS obstruction while maintaining shunt function with minimal to no complications.