Nd: YAG laser rescue of sulcus-placed glaucoma drainage device tube occlusion: a two-case series

Tube occlusion after glaucoma drainage device (GDD) implantation is a recognized complication typically requiring surgical revision. The Aurolab Aqueous Drainage Implant (AADI) is a cost-effective device increasingly used in low- and middle-income countries, yet, to our knowledge, laser management of AADI tube blockage has not been reported. Two consecutive cases of postoperative AADI tube obstruction were managed with Nd: YAG laser. Case 1 was an 11-year-old one-eyed girl with primary congenital glaucoma and a failed trabeculotomy-trabeculectomy who developed iris obstruction of a sulcus-placed AADI tube 10 months after implantation. Nd: YAG laser iridotomy restored tube patency. A transient intraocular pressure (IOP) spike, mild hyphema, and moderate anterior chamber reaction occurred and resolved spontaneously within 3 days. At 7 months, IOP remained 12 mmHg without anti-glaucoma medication and no re-occlusion. Case 2 was a 38-year-old one-eyed aphakic man with extensive flame burn, prior bilateral penetrating keratoplasty, and open-sky vitrectomy who developed vitreous tube occlusion 4 weeks after AADI implantation. Nd: YAG vitreolysis reduced IOP from 32 to 28 mmHg within 2 h. However, on day 16 post-laser, conjunctival erosion with plate exposure, bullous keratopathy, and tube migration developed in the setting of limbal stem cell deficiency, necessitating implant explantation. Nd: YAG laser may serve as a practical first-line rescue for iris- or vitreous-related obstruction of sulcus-placed GDD tubes in selected high-risk eyes, potentially avoiding immediate surgical revision. This approach is cost-effective and relevant in resource-limited settings. However, long-term success depends on the underlying ocular surface and structural condition of the eye.