IMAGING ZONULAR ABNORMALITIES USING ULTRASOUND BIOMICROSCOPY

Objectives: To evaluate the use of ultrasound biomicroscopy (UBM) in d etecting ciliary zonular defects and to describe the UBM signs of such defects. Methods: Eighteen eyes of 18 patients with clinically suspec ted zonular abnormalities were evaluated using UBM. Predisposing facto rs included pseudoexfoliation, congenital spherophakia, surgical proce dure, trauma, and the Marfan syndrome. Results: Of 18 eyes, 11 showed UBM evidence of missing zonules and 11 showed evidence of zonular stre tch. Four of the 18 eyes had both missing and stretched zonular fibers . All of the eyes examined showed increased lenticular sphericity in t he area of zonular disorder. Nine eyes showed ciliary body flattening. Pupillary block was seen in 5 patients, and angle crowding due to dir ect iridal rotation was noted in 3. Conclusions: Ultrasound biomicrosc opy can detect zonular loss and stretching directly. Increased lenticu lar sphericity and ciliary body flattening are signs of zonular defect s. Angle closure mechanisms include pupillary block and direct iridal rotation.