Nd:YAG laser goniopuncture after deep sclerectomy: outcomes

Purpose: This study aimed to investigate the safety and efficacy of Nd:YAG laser goniopuncture (LGP) in lowering intraocular pressure (IOP) after deep sclerectomy (DS). Methods: We reviewed the outcomes in 258 eyes of 258 consecutive patients who underwent DS or combined phacoemulsification and DS between August 2001 and December 2003. Mitomycin C was used during surgery in 192 eyes (74.4%). Results: Mean follow-up was 40 +/- 11 months after DS and 31 +/- 12 months after LGP. Laser goniopuncture was performed in 173 eyes (67.0%). The mean interval between LGP and DS was 10.3 +/- 8.7 months. The probability of LGP being performed was 63.1% (95% confidence interval [CI] 57.3-69.4) at 36 months after surgery. At 2 years after LGP, the probability of maintaining IOP < 15 mmHg with a 20% decrease from the pre-laser IOP and no further glaucoma procedure or medication was 49.7% (95% CI 41.9-57.1). Iris covering the trabeculo-Descemet's membrane was the only factor significantly associated with the failure of LGP (hazard ratio 3.0, p < 0.001). Complications observed after LGP included peripheral anterior synechiae in 23 (13.2%), hypotony in seven (4.0%), late acute IOP rise in three (1.7%), delayed bleb leak in one and blebitis in two eyes. Argon laser iridoplasty was performed in 45 (26.0%) and needle revision in 41 (23.7%) eyes. Conclusions: ND:YAG laser goniopuncture is an effective procedure to further lower IOP after DS. An IOP of < 15 mmHg is achieved and maintained for >= 2 years in about 50% of cases after a single LGP procedure. There are potentially serious complications associated with the procedure. Regular gonioscopy is recommended following LGP to detect any occlusion of the goniopuncture by the iris.