Midterm ultrasound biomicroscopy findings in eyes with successful viscocanalostomy

To show tissue changes using ultrasound biomicroscopy (UBM) in eyes with controlled intraocular pressure (IOP) after viscocanalostomy.

Consultores Oftalmológicos, Fundación Oftalmológica Argentina Jorge Malbran and Hospital Santa Lucía, Buenos Aires, Argentina.

This retrospective noncomparative case series comprised 23 eyes of 19 patients with uncontrolled open-angle glaucoma who had viscocanalostomy and UBM and a mean follow-up of 20 months +/- 5.9 (SD) (range 12 to 30 months). The UBM measurements were taken a mean of 6.8 +/- 5.9 months (range 3 to 14 months) after the viscocanalostomy. In 7 eyes, UBM was again performed a mean of 7.8 +/- 4.6 months (range 7 to 9 months) after the first study. All patients had preoperative and postoperative IOP measurements.

The mean IOP at last examination was 13.3 +/- 2 mm Hg (range 8 to 17 mm Hg). One eye had evidence of a subconjunctival bleb. All eyes had a nonreflective scleral chamber and posterior to it, a hyporeflective zone. In 7 eyes in which 2 UBMs were performed, the scleral chamber was unchanged 7 to 9 months after the first study.

The presence of a scleral chamber and absence of a subconjunctival filtering bleb are the usual UBM findings in eyes with adequate control of IOP several months after viscocanalostomy. These findings suggest that viscocanalostomy is successful when a continuous aqueous flow through the trabeculo-Descemet's membrane is present, maintaining a scleral chamber.