Case Report: Tube perforation after bleb reformation after PreserFlo MicroShunt implantation

To describe a rare case of tube perforation after PreserFlo MicroShunt (PMS) implantation and subsequent bleb revision, emphasizing the potential mechanisms involved and the strategies employed for clinical management.

An 84-year-old woman with bilateral exfoliation glaucoma underwent PMS implantation in her left eye due to uncontrolled intraocular pressure (IOP) despite receiving maximum medical therapy. The patient had a history of multiple ocular surgeries and long-term use of glaucoma eye drops. The initial surgery was uneventful; however, the patient developed hypotony and choroidal detachment after stent removal, prompting a second procedure for stent reinsertion. Subsequently, a postoperative conjunctival leak developed, and petrolatum-based ophthalmic ointment was used; however, the leakage did not improve, leading to a third surgery. During this procedure, a conjunctival defect and a 0.5-mm tear posterior to the fin of the PMS tube were identified. The device was removed, and a new PMS tube was implanted in a different quadrant. The IOP stabilized postoperatively, with no recurrent leakage or hypotony.

This is a rare case report of PMS tube perforation with a conjunctival hole. Potential contributing factors included chronic conjunctival inflammation from long-term use of glaucoma eye drops, previous ocular surgeries, and prostaglandin-associated periorbitopathy. These conditions may have resulted in tissue thinning and mechanical stress, leading to tube exposure and perforation. In addition, loss of the conjunctival barrier and subsequent exposure to petrolatum-based ophthalmic ointment may have compromised the structural integrity of the PMS, potentially leading to perforation due to continued eyelid friction. A careful preoperative assessment of the ocular surface and periocular anatomy is essential for identifying high-risk patients. Furthermore, if the PMS becomes exposed postoperatively, the use of petrolatum-based ophthalmic ointment should be avoided.