Ab-interno goniotrabeculotomy versus mitomycin C trabeculectomy for adult open-angle glaucoma: a 2-year randomized clinical trial

Ophthalmology. 1999 Jul;106(7):1357-62. doi: 10.1016/S0161-6420(99)00725-3.


Objective: To evaluate the effect of ab-interno goniotrabeculotomy (AIGT) on the intraocular pressure (IOP) in adult patients with primary open-angle glaucoma (POAG), compared with the effects of mitomycin C trabeculectomy (MT).

Design: Prospective, randomized, clinical trial.

Participants: Thirty-two eyes of 32 patients with medically uncontrolled POAG.

Intervention: Standard limbus-based trabeculectomy with adjunct mitomycin C (0.3 mg/mL for 3 minutes) in 16 eyes of 16 patients; AIGT was performed in 16 eyes of 16 patients. The groups were matched for age, preoperative IOP, duration of preoperative antiglaucoma treatment, use of preoperative beta-blockers and parasympathomimetics, and use of beta-blockers in the fellow eye. The IOP (average of the two highest values measured in the diurnal curve, from 8 AM to 6 PM, every 2 hours) and complications were recorded 1, 3, 6, 12, 18, and 24 months after surgery.

Main outcome measures: Identification of complications and IOP.

Results: All patients were followed up for 24 months. More postoperative complications occurred in the MT group during the 2-year follow-up. One month after surgery, IOP was 10 +/- 1.46 mmHg (range, 8-13) in the MT group and 12.12 +/- 1.63 mmHg (range, 8-14) in the AIGT group (Student's t test, P = 0.001). Three months after surgery, IOP was 11.5 +/- 1.59 mmHg (range, 8-14) and 12.75 +/- 1.57 mmHg (range, 10-16) in the MT and AIGT groups, respectively (Student's t test, P = 0.033). From the 6th to the 24th postoperative month, no statistically significant difference in IOP was found between the two groups. At the end of follow-up, 14 of 16 eyes (87.5%) of the AIGT group and 13 of the 16 eyes (81.25%) of the MT group showed an IOP < or = 14 mmHg.

Conclusion: Ab-interno goniotrabeculotomy appears to be a viable and safe surgical treatment for adult POAG. More extended follow-up, however, and a larger series of patients are needed to ascertain the actual effectiveness of this procedure in adult POAG.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Anterior Chamber / surgery*
  • Follow-Up Studies
  • Glaucoma, Open-Angle / drug therapy*
  • Glaucoma, Open-Angle / surgery*
  • Gonioscopy
  • Humans
  • Intraocular Pressure
  • Middle Aged
  • Mitomycin / therapeutic use*
  • Postoperative Complications
  • Prospective Studies
  • Trabeculectomy / methods*
  • Treatment Outcome


  • Mitomycin