Scleral indentation optimizes visualization of anterior chamber angle during goniosynechialysis.

PURPOSE: To propose a new surgical technique for optimized visualization of the chamber angle using scleral indentation under an operating microscope in goniosynechialysis (GSL).

PATIENTS AND METHODS: Six volunteers with normal chamber angle and five patients with synechial angle closure glaucoma were examined. Scleral indentation 2 mm posterior to the limbus was performed during observation of chamber angle. Width of trabecular meshwork in images was recorded through a CCD camera mounted on an operating microscope. Trabecular-iris angle and trabecular-corneal angle obtained by ultrasound biomicroscopy were used for the parameters for the angle configuration. GSL with scleral indentation was performed in the patients.

RESULTS: According to the visibility of the chamber angle, width of trabecular meshwork in images significantly increased from 0.34 +/- 0.08 mm equivalent (mean +/- SD) to 0.67 +/- 0.14 mm equivalent (P = 0.0001) with scleral indentation. According to the angle configurations, trabecular-iris angle significantly increased from 39.6 +/- 3.8 degrees to 47.5 +/- 6.6 degrees (P = 0.0016), and trabecular-corneal angle significantly decreased from 169.8 +/- 5.5 degrees to 158.7 +/- 5.4 degrees (P < 0.0001). All patients were successfully treated with GSL using scleral indentation.

CONCLUSION: Scleral indentation provided the surgeon an optimized visualization of the anterior chamber angle. Deepening of the chamber angle and steeping in trabecular-corneal curvature probably induced the plane of the trabecular meshwork less oblique to the surgeon's visual axis. This enhanced visualization promises the accuracy and safety of GSL.