A Study of the Structure and Function of the Retina in Adult Patients With Refractory Complex Partial Seizures Treated With Vigabatrin (Sabril®)
Condition: Adult Refractory Complex Partial Seizures
MeSH terms: Seizures
Intervention: Sabril
Intervention description: Sabril: 500 mg tablets, orally. Physicians will dose their patients according to guidance provided in the product label.
Intervention MeSH terms: Vigabatrin
Phase: Phase 4
Study type: Interventional
Primary purpose: Supportive Care
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 65.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: Vigabatrin-associated vision change; Adult refractory complex partial seizures; CPS; Epilepsy; Seizures; Brain diseases; Central Nervous System Diseases; Nervous System Diseases; Neurologic Manifestations; Enzyme Inhibitors; GABA Agents

Summary:

      The purpose of the study is to evaluate the change in visual fields by means of automated
      static perimetry and to evaluate the change in retinal structure by means of spectral domain
      optical coherence tomography (SD-OCT) in adult patients with refractory complex partial
      seizures (CPS) being treated with vigabatrin (Sabril®)
    

Eligibility criteria:

        Important Inclusion Criteria:

          1. The patient speaks English or Spanish.

          2. The patient has had no prior exposure to Sabril.

          3. To begin Sabril therapy for the treatment of CPS.

          4. Male or female ≥18 years of age.

          5. The patient has refractory CPS:

               1. The patient has complex partial epilepsy of more than 1 year duration and no
                  other seizure type within the past year except for partial seizures secondarily
                  generalized.

               2. The patient has failed because of lack of efficacy 3 or more prior or concurrent
                  treatment trials including 3 or more anti-epileptic drugs (AEDs) of differing
                  pharmacologic mechanisms administered as monotherapy or polytherapy.

               3. The patient is taking at least 1 AED. A vagal nerve stimulator is not counted as
                  an AED.

               4. The patient reports an average of 2 or more seizures per month averaged over the
                  prior 3 months.

          6. The patient is deemed by the treating neurologist and ophthalmologist to be able to
             reliably complete perimetry testing.

          7. The initial (Visit 1) SD-OCT and static perimetry readings tests must be performed and
             assessed for technical adequacy by the SD-OCT and perimetry central readers prior to
             the first dose of Sabril. The initial (Visit 1) tangent corner test must be performed
             prior to the first dose of Sabril.

        Exclusion Criteria:

          1. Prior exposure to Sabril.

          2. Pre-existing ocular or neurological disease that might affect bilateral visual fields
             or interfere with perimetry (e.g., aphakia, visually significant cataract, glaucoma,
             diabetes mellitus, ischemic optic neuropathy, multiple sclerosis). Patients with
             stable visual field defects from CNS lesions (e.g., epilepsy surgery more than 6
             months prior to receiving Sabril) may be enrolled.

          3. Concurrent exposure to medications with known or suspected retinal or optic nerve
             toxicity.

          4. Concurrent use of an investigational agent or device or such use within 30 days of
             entering the study.

          5. Concurrent use of the ketogenic or similar diet.

          6. For any reason, the patient is considered by the investigator to be an unsuitable
             candidate for the study.