title: Retinal structure and function in vigabatrin-treated adult patients with refractory complex partial seizures.
abstract: OBJECTIVE
  Evaluate visual-field and retinal-structure changes following adjunctive vigabatrin treatment in vigabatrin-naive adults with refractory complex partial seizures (rCPS).
  
  
  METHODS
  Prospective, longitudinal, single-arm, open-label study (NCT01278173). Eligible patients (≥2 seizures/month who failed ≥3 therapies) who could reliably perform perimetry (Humphrey automated static) and retinal-structure assessment (spectral-domain optical coherence tomography) prior to vigabatrin exposure. Following vigabatrin initiation, testing occurred within 1 month (reference) and 3, 6, 9, and 12 months. End points included mean change from reference in mean deviation (dB) and average retinal nerve fiber layer (RNFL) thickness, visual-acuity changes from baseline, and number of patients who met predefined vision-parameter changes at two (confirmed) or three (persistent) consecutive visits.
  
  
  RESULTS
  Sixty-five of 91 screened patients received ≥1 vigabatrin dose (all-patients-treated set [APTS]); 55 had valid reference and ≥1 post-reference assessments (full-analysis set [FAS]). Thirty-six APTS patients with valid pre-/post-reference values completed all planned visits (per-protocol set [PPS]). Thirty-eight (59%) APTS patients completed the study; 27 (42%) withdrew (none for visual-field changes); 32% and 15% had abnormally thin RNFL and abnormal visual acuity at baseline, respectively; 20% had abnormal central 30 degree visual fields in the reference period. No significant mean near visual-field changes were observed (PPS); mean change in average RNFL thickness increased significantly (1-year data: Left-eye: 6.37 μm, confidence interval (CI) 4.66-8.09; right-eye: 7.24 μm CI 5.47-9.01; PPS). No confirmed three-line decreases in visual acuity (FAS) were observed; five patients had predefined confirmed/persistent visual-field changes (FAS). All vision-related adverse events were nonserious; the most common was vision blurred (9%).
  
  
  CONCLUSIONS
  Prior to vigabatrin initiation, rCPS patients may already exhibit vision deficits. Up to 1 year of adjunctive vigabatrin treatment did not significantly change population near visual fields. Five patients met predefined visual-field-change criteria. RNFL thickening of unknown clinical significance was observed. Limitations include single-arm, open-label design; patients' inability to perform ophthalmic/visual-field examinations; and limited vigabatrin-exposure duration.
authors: Wills Eye Institute and Thomas Jefferson University Medical College, Philadelphia, Pennsylvania, U.S.A. rcs220@comcast.net.
authors: Robert C
authors: RC
authors: Sergott
authors: Department of Ophthalmology & Visual Sciences, University of Iowa Hospitals & Clinics, Iowa City, Iowa, U.S.A.
authors: Chris A
authors: CA
authors: Johnson
authors: California Pacific Medical Center, San Francisco, California, U.S.A.
authors: Kenneth D
authors: KD
authors: Laxer
authors: Idaho Comprehensive Epilepsy Center, Boise, Idaho, U.S.A.
authors: Robert T
authors: RT
authors: Wechsler
authors: Lundbeck LLC, Deerfield, Illinois, U.S.A.
authors: Katya
authors: K
authors: Cherny
authors: Lundbeck LLC, Deerfield, Illinois, U.S.A.
authors: JoAnn
authors: J
authors: Whittle
authors: Lundbeck LLC, Deerfield, Illinois, U.S.A.
authors: Ge
authors: G
authors: Feng
authors: Lundbeck LLC, Deerfield, Illinois, U.S.A.
authors: Deborah
authors: D
authors: Lee
authors: Lundbeck LLC, Deerfield, Illinois, U.S.A.
authors: Jouko
authors: J
authors: Isojarvi
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000009:adverse effects*; D017029:Epilepsy, Complex Partial / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009412:Nerve Fibers / Q000187:drug effects / Q000473:pathology; D012160:Retina / Q000187:drug effects* / Q000473:pathology; D041623:Tomography, Optical Coherence; D020888:Vigabatrin / Q000009:adverse effects*; D014786:Vision Disorders / Q000139:chemically induced*; D058609:Visual Field Tests; D014794:Visual Fields / Q000187:drug effects*
chemical_list: D000927:Anticonvulsants; D020888:Vigabatrin
keywords: Clinical trial; Optical coherence tomography; Refractory complex partial seizures; Retinal structure; Vigabatrin; Vision data