Pfizer Clinical Trial Infographic-PDF Version

Study Title

“Prospective randomized 12-week controlled study of visual field change in subjects with partial seizures receiving Pregabalin or placebo”

What is this study about?

This three month study will look at people between 18-65 years old, taking their own anti-seizure medications in addition to either the study drug (Pregabalin) or a placebo. The aim is to look for changes in eyesight. Visual fields (the size of the area you can see with each eye) and visual acuity (how clear your vision is) will be measured in people before, during ,and after the 13-week study.

How will the study benefit me? What is the potential harm?

The study is being done to learn more about how the study drug, Pregabalin (Lyrica), can be used safely. This study may not provide a benefit to you personally. Pregabalin has been approved by the FDA in the United States for use as an add-on treatment for people with focal seizures, as well as for neuropathic (nerve) pain and fibromyalgia. However, as pregabalin came into use around 2004, another drug, vigabatrin, was reported to cause visual field disturbances or problems with eyesight. Because these two drugs share some similarities, eyesight effects are now being evaluated in patients taking Pregabalin. 

How can I participate? 

The first step is to see if the study is right for you at a screening visit with your healthcare provider. A study team member will explain the details of the study with you. If you qualify and are willing, you can give your consent to participate. (You can always choose to withdraw from the study at any time.) Some or all of the following tests will be done: 
Your eyes will also be examined at this time. The pupils are dilated to see the back of the eye, as well as non-invasive vision testing.
If you are eligible for this study, you will be put into either the trial drug (Pregabalin) group or the placebo group. You will take the study drug or the placebo, whichever you are assigned, in addition to your usual anti-seizure medications.
Over 12 weeks, you will have several check-ups with your healthcare provider. Some or all of the following will be done at these visits: physical exam, external eye exam, blood and urine sample collection, review of medication dosage, and discussion of seizure frequency.
If you are found to have any visual effects, you will also have visual testing done at the follow-up (week 15) visit. Any visual effects requiring follow-up after week 15 will be supported by Pfizer.

Who is eligible to join the study?

  • People between the ages of 18-65
  • Diagnosis of epilepsy with partial (focal) seizures
  • Currently being treated with one to three anti-seizure medications

For more information: