Evaluation of posterior lens capsule by 20-MHz ultrasound probe in traumatic cataract. 
To investigate the accuracy of echography with a 20-MHz probe for evaluation of posterior lens capsule in traumatic cataract before surgery.  Prospective interventional case series.  This study consisted of 43 eyes with traumatic cataract that were scheduled to undergo surgery.  In all cases, cataract was dense enough to prevent visualization of the posterior lens capsule.  Echography was performed using a 20-MHz probe to detect rupture of the posterior lens capsule.  All patients subsequently underwent cataract extraction and intraoperative findings of the posterior lens capsule were compared with the preoperative echographic findings.  This study included 43 eyes of 43 patients (38 men and 5 women) with a mean age of 35.6 ± 15.3 years (range, 4-68 years).  The trauma was either blunt (4 eyes) or sharp (39 eyes); there was closed globe injury in 2 eyes and open globe injury in 41 eyes.  By 20-MHz echography, posterior border of the crsytalline lens was clearly visualized in all 43 eyes.  By 20-MHz echographic imaging, rupture of the posterior lens capsule was identified in 17 eyes (39.5%).  During cataract surgery, it was noted that 14 eyes (32.6%) had rupture of the posterior lens capsule.  Sensitivity, specificity, positive predictive value, and negative predictive value were 93%, 86%, 76%, and 96%, respectively, for 20-MHz echography to detect rupture of the posterior lens capsule.  Also, the positive likelihood ratio, negative likelihood ratio, and odds ratio were 6.7, 0.08, and 81, respectively.  Echography with 20-MHz probe is an accurate imaging modality for detection of posterior lens capsule rupture in traumatic cataract preoperatively.  This technique helps ophthalmologists have an appropriate surgical plan before operating.