Retrospective evaluation of a filtering trabeculotomy in comparison to conventional trabeculectomy byexact matching

Abstract

Purpose: To compare 2-year results of a filtering trabeculotomy (FTO) to conventional trabeculectomy (TE) in open-angle glaucoma by exact matching. Methods: 110 patients received an FTO and 86 a TE. FTO avoided the need for an iridectomy due to a preserved trabeculo-Descemet window anterior to the scleral flap. TE employed a trabecular block excision and iridectomy. Mitomycin C was used in both. FTO and TE were exact-matched by baseline intraocular pressure (IOP) and the number of glaucoma medications. Complete and qualified success (IOP ≤18 mmHg and IOP reduction ≥ 30%, with or without medication) were primary endpoints. IOP, visual acuity (BCVA), complications and intervention were secondary endpoints. Results: 44 FTO were exact-matched to 44 TE. The IOP baseline in both groups was 22.5+/-4.7 mmHg on 3+/-0.9 medications. At 24 months, complete success was reached by 59% in FTO and 66% in TE and qualified success by 59% in FTO and 71% in TE. In FTO, IOP was reduced to 12.4+/-4.3 mmHg at 12 months and 13.1+/-4.1 mmHg at 24 months. In TE, IOP was 11.3+/-2.2 mmHg at 12 months and 12.0+/-3.5 mmHg at 24 months. Medications could be reduced at 24 months to 0.6+/-1.3 in FTO and 0.2+/-0.5 in TE. There were no significant differences between the two groups in IOP, medications, complications or interventions at any point. Conclusion: Modifying aqueous flow through a limited trabeculotomy in FTO yielded clinical outcomes similar to traditional TE but allowed to avoid an iridectomy.