A-stream Shunt Implantation for Secondary Glaucoma after Penetrating Keratoplasty: A Case Series

Purpose: To evaluate the clinical outcomes of A-stream glaucoma shunt implantation for medically refractory secondary glaucoma after penetrating keratoplasty (PKP). Methods: This retrospective interventional case series included four eyes of four patients with uncontrolled secondary glaucoma following PKP who underwent A-stream glaucoma shunt implantation at a single tertiary center. Clinical data collected included preoperative and postoperative intraocular pressure (IOP), number of glaucoma medications, tube location, postoperative interventions, complications, and corneal graft status. Outcomes assessed included postoperative IOP reduction and graft preservation. Results: Four eyes of four patients were included. The indications for PKP were corneal ulcer in two eyes, bullous keratopathy in one eye, and old traumatic corneal opacity in one eye. The interval between PKP and A-stream implantation ranged from 1 to 5 months. Mean preoperative IOP was 42.8 ± 7.8 mmHg (range, 35-53 mmHg), which decreased to 14.5 ± 2.4 mmHg (range, 12-17 mmHg) at the final follow-up visit. The mean follow-up duration was 8.0 ± 2.8 months (range, 6-12 months). All eyes achieved IOP control without glaucoma medications at the final follow-up visit. One eye required bleb needling, one eye showed spontaneous ripcord loss without adverse sequelae, and one eye underwent ripcord removal during follow-up. No hypotony-related complications, including persistent hypotony or choroidal effusion, were observed. Conclusions: In this small retrospective series, A-stream shunt implantation was associated with substantial short-term IOP reduction and a reduced need for glaucoma medications in eyes with medically refractory glaucoma after PKP. The procedure appeared to have a favorable short-term safety profile, with preservation of graft clarity in all four cases. A-stream implantation may represent a feasible surgical option for medically refractory glaucoma after PKP ,although larger studies with longer follow-up are needed to confirm long-term efficacy and graft safety, including quantitative endothelial cell density assessment.