title: Effects of topical brinzolamide on infantile nystagmus syndrome waveforms: eyedrops for nystagmus.
abstract: BACKGROUND
  Recent advances in infantile nystagmus syndrome (INS) surgery have uncovered the therapeutic importance of proprioception. In this report, we test the hypothesis that the topical carbonic anhydrase inhibitor (CAI) brinzolamide (Azopt) has beneficial effects on measures of nystagmus foveation quality in a subject with INS.
  
  
  METHODS
  Eye movement data were taken, using a high-speed digital video recording system, before and after 3 days of the application of topical brinzolamide 3 times daily in each eye. Nystagmus waveforms were analyzed by applying the eXpanded Nystagmus Acuity Function (NAFX) at different gaze angles and determining the longest foveation domain (LFD) and compared to previously published data from the same subject after the use of a systemic CAI, contact lenses, and convergence and to other subjects before and after eye muscle surgery for INS.
  
  
  RESULTS
  Topical brinzolamide improved foveation by both a 51.9% increase in the peak value of the NAFX function (from 0.395 to 0.600) and a 50% broadening of the NAFX vs Gaze Angle curve (the LFD increased from 20° to 30°). The improvements in NAFX after topical brinzolamide were equivalent to systemic acetazolamide or eye muscle surgery and were intermediate between those of soft contact lenses or convergence. Topical brinzolamide and contact lenses had equivalent LFD improvements and were less effective than convergence.
  
  
  CONCLUSIONS
  In this subject with INS, topical brinzolamide resulted in improved-foveation INS waveforms over a broadened range of gaze angles. Its therapeutic effects were equivalent to systemic CAI. Although a prospective clinical trial is needed to prove efficacy or effectiveness in other subjects, an eyedrops-based therapy for INS may emerge as a viable addition to optical, surgical, behavioral, and systemic drug therapies.
authors.affiliation: Daroff-Dell'Osso Ocular Motility Laboratory, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, 10701 East Boulevard, Cleveland, OH 44106, USA. lfd@case.edu
authors.forename: Louis F
authors.initials: LF
authors.lastname: Dell'osso
authors.forename: Richard W
authors.initials: RW
authors.lastname: Hertle
authors.forename: R John
authors.initials: RJ
authors.lastname: Leigh
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Jacobs
authors.forename: Susan
authors.initials: S
authors.lastname: King
authors.forename: Stacia
authors.initials: S
authors.lastname: Yaniglos
mesh_terms: D000368:Aged; D058256:Brain Waves / Q000187:drug effects* / Q000502:physiology*; D002257:Carbonic Anhydrase Inhibitors / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D009759:Nystagmus, Pathologic / Q000151:congenital / Q000188:drug therapy*; D009801:Oculomotor Muscles / Q000187:drug effects / Q000294:innervation; D009882:Ophthalmic Nerve / Q000187:drug effects; D009883:Ophthalmic Solutions / Q000627:therapeutic use*; D013449:Sulfonamides / Q000008:administration & dosage*; D013843:Thiazines / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D009883:Ophthalmic Solutions; D013449:Sulfonamides; D013843:Thiazines; C111827:brinzolamide