Retrospective evaluation of two-year results with a filtering trabeculotomy in comparison to conventional trabeculectomy by exact matching [version 1; peer review: 3 approved]

• Published in: F1000 research Vol. 9; p. 1245
• Main Authors: Strzalkowska, Alicja, Strzalkowski, Peter, Al Yousef, Yousef, Hillenkamp, Jost, Grehn, Franz, Loewen, Nils A
• Format: Journal Article
• Language: English
• Published: England F1000 Research Ltd 2020
• Subjects: Alpha-Ketoglutarate-Dependent Dioxygenase FTO; Glaucoma, Open-Angle - surgery; Humans; Retrospective Studies; Tonometry, Ocular; Trabeculectomy; Treatment Outcome; open-angle glaucoma; trabeculotomy; mitomycin C; exact matching; trabeculectomy; iridectomy
• ISSN: 2046-1402; 2046-1402
• DOI: 10.12688/f1000research.26772.1

Background: To compare two-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.