Intraocular hypotony: Use of ultrasound biomicroscopy (UBM) for the schematic approach of its differential diagnosis

Objectives: To determine the use of high-frequency ultrasound biomicroscopy (UBM) in the assessment of hypotony and in particular to determine the pro portion of cases for which UBM contributed significant additional hitherto unaccessible information. Patients and Methods: Ultrasound biomicroscopy was performed in a standard manner, using a Humphrey UBM 840 system (Humphrey Instruments, Inc., San Le andro, CA). UBM findings were analysed and the clinical relevance of UBM in formation was determined for the whole collective. Results: Twelve patients with hypotony were examined. UBM findings contribu ted essential information that allowed to reach a diagnosis or that determi ned the therapeutic attitude in 10 of the 12 hypotonic patients. In two cas es the cause of hypotony was tractional ciliary body detachment, in 5 cases it was post-inflammatory atrophy of the ciliary body, in 3 cases it was po st-traumatic irido and cyclodialysis, in one case it was supraciliary and s uprachoroidal effusion and in the last case it was due to uveal effusion sy ndrome. Based on these findings we established a schematic approach for hyp otony Conclusions: This procedure enabled us to assess the morphological changes found in patients with hypotony. In a majority of cases UBM was useful eith er to orient therapeutic intervention or to establish a diagnosis. On the b ase of our findings a schematic approach for hypotony, using UBM, was estab lished.