Improved nonpenetrating trabeculectomy with trabeculotomy

Retrospective evaluation of two-year results with a filtering trabeculotomy in comparison to conventional trabeculectomy by exact matching

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.

A comparative study of a modified filtering trabeculotomy and conventional trabeculectomy

Purpose

The objective of the study reported here was to evaluate the outcome of a modified filtering trabeculotomy (FTO) without iridectomy in open-angle glaucoma compared with that of conventional trabeculectomy (trab).

Patients and methods

Thirty eyes of 30 patients who underwent modified FTO were prospectively followed for 1 year and were compared with 87 conventional trab patients (87 eyes), matched for age and preoperative intraocular pressure (IOP). The FTO procedure consisted of a deep sclerectomy and trabeculotomy preserving the trabeculo-Descemet membrane, without iridectomy. Main outcome measures were complete success (IOP <18 mmHg and >/=30% IOP reduction, without medication), IOP, visual acuity, medication, complications, and subsequent surgeries.

Results

In the conventional trab group, the median preoperative IOP was 23.0 mmHg (interquartile range 20.0–27.0) with 3.0 (2.0–3.0) medications, compared with 23.0 mmHg (20.0–27.0) and 3.0 (2.8–4.0) in the modified FTO group. Median postoperative IOP at 12 months was 12.0 mmHg (10.0–13.0) in the conventional trab and 11.0 mmHg (8.0–14.0) in the modified FTO group (P=0.3). The complete success rate at 1 year was 83.1% and 79.3% in the conventional trab group and modified FTO group, respectively (P=0.8). The complications hypotony (20.7%, 24.1%), choroidal detachment (2.3%, 10.3%), and bleb scarring (17.2%, 13.8%), were present in the conventional trab group and modified FTO group, respectively.

Conclusion

The outcomes of reduced IOP and medications in the FTO group were not different to those in the conventional trab group over 1 year, but some complications were more often seen with the modified FTO technique. The new filtration trabeculotomy, however, has the advantage of avoiding iridectomy, thus reducing the risk of cataract formation, and may result in the development of more favorable blebs by controlling the flow over two resistance levels.

Dilation and probing of Schlemm's canal and viscocanalostomy in pediatric glaucoma

PURPOSE

To describe the authors' experience using a novel surgical technique for treatment of childhood glaucoma.

METHODS

Medical records of 24 consecutive patients and 39 eyes that underwent dilation and probing of Schlemm's canal and viscocanalostomy between September 2002 and June 2008 were reviewed. Surgical success was defined as an intraocular pressure (IOP) of less than 23 mm Hg with or without glaucoma medication and without further surgical intervention.

RESULTS

Mean age at surgery was 66 ± 66 months, with a mean preoperative IOP of 40.4 ± 10.2 mm Hg. Surgical success was achieved in 27 of 39 eyes (69%) with an average follow-up of 22 months. In patients without history of previous surgery and the diagnosis of primary congenital or juvenile glaucoma, surgical success was achieved in 17 of 19 eyes (89%) with an average follow-up of 20 months. There were no serious surgical complications associated with this procedure.

CONCLUSION

Goniosurgery with dilation and probing of Schlemm's canal in combination with viscocanalostomy appears to be a safe and effective surgical modality to lower IOP. The procedure appears to be most effective in surgically naïve primary congenital and juvenile glaucoma.