Holmium laser sclerostomy in glaucoma management: a new tool for an old procedure

A THC: YAG laser (thulium, holmium, chromium doped YAG crystal) was used to create thermal sclerostomies in 49 glaucomatous eyes of 46 patients. The laser is a long-pulsed (300 microseconds), compact, self contained, solid state laser operating in the near infrared (2.1 mu). A 1 mm conjunctival stab incision was made 12 mm away from the sclerostomy site to allow entry of a specially designed 22-gauge (712 mu) optic probe that delivers energy at a right angle to the long axis of the fiber. Probe insertion produced minimal disturbance of the conjunctiva. Pulse energies of 80 mJ tot 120 mJ were used with a repetition rate of 5 pulses/sec. Total energy levels to produce full-thickness sclerostomies ranged from 1.4 to 7.2 J. Subconjunctival 5-fluorouracil injections were administered in 46 eyes. Estimated probability of success was 74% at 6 months and 67% at 12 months. Mean intraocular pressure of successful cases was 13.3 mmHg at both both 6 months & 12 months. Twelve cases failed within the initial 6 months, and two additional cases failed by 12 months.