title: Smooth-pursuit changes after the tenotomy and reattachment procedure for infantile nystagmus syndrome: model predictions and patient data.
abstract: OBJECTIVE
  Patients with infantile nystagmus syndrome (INS) often cannot quickly locate new visual targets or track moving objects. Dynamic demands on visual function are not measured by static measures (eg, visual acuity); they require time-sensitive measures. The authors investigated how dynamic properties of INS (pursuit-target acquisition times) were affected by the tenotomy and reattachment (T&R) procedure in both patients with INS and behavioral ocular motor system model predictions.
  
  
  METHODS
  Responses of 3 patients with different INS waveforms were compared before and after T&R to test the model's predictions. A high-speed digital video system was used to take eye-movement data. Human responses to target-ramp stimuli were analyzed.
  
  
  RESULTS
  T&R did not improve the smooth-pursuit responses of patients with INS; pursuit-target acquisition times did not show marked improvements. However, in one case, T&R allowed the patient to pursue targets "faster" in a specific direction.
  
  
  CONCLUSIONS
  T&R can improve peak visual acuity, broaden the high-acuity gaze-angle range, and reduce target acquisition times to static targets but not moving targets. When the target moves simultaneously with an ongoing saccade in the nystagmus cycle, the steady-state errors and elongated target acquisition times observed might be part of the intrinsic characteristics of normal pursuit responses.
authors.affiliation: Daroff-Dell’Osso Ocular Motility Laboratory, Laboratory, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA.
authors.forename: Zhong I
authors.initials: ZI
authors.lastname: Wang
authors.forename: Louis F
authors.initials: LF
authors.lastname: Dell'Osso
authors.forename: Surachi
authors.initials: S
authors.lastname: Prakash
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
mesh_terms: D000328:Adult; D003198:Computer Simulation; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D008297:Male; D008875:Middle Aged; D020417:Nystagmus, Congenital / Q000503:physiopathology / Q000601:surgery*; D009801:Oculomotor Muscles / Q000503:physiopathology / Q000601:surgery*; D011698:Pursuit, Smooth / Q000502:physiology*; D013577:Syndrome; D013709:Tendon Transfer; D058971:Tenotomy; D014741:Video Recording; D014792:Visual Acuity / Q000502:physiology