Occult wound leak diagnosed by ultrasound biomicroscopy in patients with postoperative hypotony.

Purpose: To describe the ability of high-frequency ultrasound biomicroscopy (UBM) to diagnose occult wound leaks as a cause for hypotony after cataract surgery.
Methods: Six patients with persistent hypotony after cataract surgery were sent for UBM examination. Slitlamp examination and gonioscopy of the 6 eyes had not revealed a cause for the hypotony.
Results: Ultrasound biomicroscopy showed subtle wound separation with shallow conjunctival elevation at the site of the cataract wound in the 6 patients. Two eyes had surgical repair of the subconjunctival wound leak, and the other 4 were treated medically. In the 2 eyes with surgically repaired wounds, the hypotony cleared after wound closure. Of the 4 medically treated eyes, hypotony resolved in 2 and 1 had a recurrence of hypotony. The other 2 eyes had fluctuating intraocular pressure for an extended period.
Conclusions: Hypotony after cataract surgery occurred in 6 eyes due to subtle wound leaks difficult to detect by clinical observation. Ultrasound biomicroscopy can be a helpful aid to clinical examination in detecting these leaks.