Button: text/icon vertical alignment is off

I have a few buttons with icons and noticed that the text does not always align well vertically with the icon.
I’ve tried various combinations.

<button ion-button icon-left block>
  <ion-icon name="videocam"></ion-icon>

The results on different platforms with different sizes and combinations:


The icon is a few pixels lower than the text in most cases.

For now, I’m going with the following for those buttons that look off:

<button ion-button icon-left block>
  <ion-icon name="videocam" class="adjust-top"></ion-icon>
  Choose video ...


.button-inner ion-icon.adjust-top {
  position: relative;
  top: -1px;