Nd:YAG laser goniopuncture after deep sclerectomy: outcomes

Abstract

This study aimed to investigate the safety and efficacy of Nd:YAG laser goniopuncture (LGP) in lowering intraocular pressure (IOP) after deep sclerectomy (DS). 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%). 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. ND:YAG laser goniopuncture is an effective procedure to further lower IOP after DS. An IOP of < 15 mmHg is achieved and maintained for > or = 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.