optimization array read

gistfile1.php

$array = array(
  'field_item_1' => array(
    'field_sub_item_11' => array('field' => TRUE, 'title' => 'sub field item 1'),
    'field_sub_item_12' => array('field' => FALSE, 'title' => 'sub field item 2'),
  ),
  'field_item_2' => array(
    'field_sub_item_21' => array('field' => TRUE, 'title' => 'sub field item 21'),
  ),
);

foreach ($array as $item => $field) {
  // I do not want to have this foreach.
  foreach ($field as $k => $v) {
    if ($v['field']) {
      // Do something.
    }
  }
}