Ultrasound biomicroscopy in chronic ocular hypotony: its impact on diagnosis and management.

Abstract

To determine the value of ultrasound biomicroscopy (UBM) in the assessment of ocular hypotony in cases where the underlying pathologic mechanism remains unclear after extensive clinical examination. In a retrospective study, the records of 60 patients who had undergone UBM to elucidate the underlying structural abnormalities of chronic ocular hypotony (intraocular pressure of 0-8 mmHg) were evaluated. Most patients (47 of 60 eyes) had a history of intraocular surgery or of other ocular diseases (e.g., uveitis), and after careful clinical examination, the cause had remained unclear. All patients were observed up for a minimum of 12 months. The associated pathoanatomy of the hypotony was demonstrated by UBM in 95% of the cases. Ciliary body abnormalities were present in 80% of the eyes. Therapeutic intervention was associated with restoration of normal ocular pressure in 50% of the cases. Often more than one intervention was necessary. A long duration of hypotony did not impede reaching the therapeutic goal of normalizing intraocular pressure and preventing phthisis. Ultrasound biomicroscopy is a new tool for detecting the underlying structural abnormalities in ocular hypotony. In cases where clinical examination is not sufficient it can be of great help in deciding on a course of treatment.