You've worked very diligently to help Johnny or Mary to read, but they are getting far behind and nothing seems to work. Barring any emotional, visual, or neurological impairment, why not try an approach you may not have thought of?
Definition: "Tape assisted reading is an individual or group reading activity where students read along in their books as they hear a fluent reader read the book on an audiotape [or CD]. As confidence and reading skills develop, students read the same passage or text without the assistance of the tape." (Readingingrockets.org)