After 4 years post-LASIK surgery, do I still need to use an eye drop without preservatives? I still have dry eyes every day.

Dry eye is indeed one of the common post-LASIK side effects. For the vast majority of patients, the dryness does tend to taper off and get better and better months after the procedure. However, it seems like you are still experiencing rather severe symptoms of dryness despite being diligent in using your lubricating eyedrops and gel. Apart from monitoring your symptoms and continuing the usage of your eyedrops and gel, you may also want to assess your environment and work habits.

Dry eye syndrome can span a spectrum from mild to moderate and severe. Treatment protocols also may vary from clinic to clinic, but it is worth mentioning the goals of treatment and the general principles that can be used to alleviate the problem. Among the problems associated with dry eyes is the development of punctate corneal epithelial erosions (little dry spots on the cornea). If a large number of these appear and if they develop in the centre of the cornea, vision will become blurred. In the worst cases, some amount of scarring can also develop.