I do not know whether it is Word 2013 issue or not? Did any guy face this problem. In the given image you may observe the problem.
The first line shows a large single ligature shown correctly by Word 2013 but the same ligature does not appear completely at smaller sizes. At smaller point size the right side of the ligature do not appear as in the lower lines in the above image. But it is a view issue only (not printing issue) and so if I zoom in, the same ligature appear correctly. All the the larger ligatures show same issue in the otf. The problem appears in otf file only while the ttf is shown correctly by Word 2013. The same otf file works correctly in Word 2010 and InDesign CS6.