title: Combining recessions (nystagmus and strabismus) with tenotomy improved visual function and decreased oscillopsia and diplopia in acquired downbeat nystagmus and in horizontal infantile nystagmus syndrome.
abstract: OBJECTIVE
  To investigate the effects of combined tenotomy and recession procedures on both acquired downbeat nystagmus and horizontal infantile nystagmus.
  
  
  METHODS
  Patient 1 had downbeat nystagmus with a chin-down (upgaze) position, oscillopsia, strabismus, and diplopia. Asymmetric superior rectus recessions and inferior rectus tenotomies reduced right hypertropia and rotated both eyes downward. Patient 2 had horizontal infantile nystagmus, a 20 degrees left-eye exotropia, and alternating (abducting-eye) fixation. Lateral rectus recessions and medial rectus tenotomies were performed. Horizontal and vertical eye movements were recorded pre- and postsurgically using high-speed digital video. The eXpanded Nystagmus Acuity Function (NAFX) and nystagmus amplitudes and frequencies were measured.
  
  
  RESULTS
  Patient 1: The NAFX peak moved from 10 degrees up to primary position where NAFX values improved 17% and visual acuity increased 25%. Vertical NAFX increased across the -10 degrees to +5 degrees vertical range. Primary-position right hypertropia decreased approximately 50%; foveation time per cycle increased 102%; vertical amplitude, oscillopsia, and diplopia were reduced, and frequency was unchanged. Patient 2: Two lateral, narrow high-NAFX regions (due to alternating fixation) became one broad region with a 43% increase in primary position (acuity increased approximately 92.3%). Diplopia amplitude decreased; convergence and gaze holding were improved. Primary-position right exotropia was reduced; foveation time per cycle increased 257%; horizontal-component amplitude decreased 45.7%, and frequency remained unchanged.
  
  
  CONCLUSIONS
  Combining tenotomy with nystagmus or strabismus recession procedures increased NAFX and visual acuities and reduced diplopia and oscillopsia in downbeat nystagmus and infantile nystagmus.
authors.affiliation: Daroff-Dell'Osso Ocular Motility Laboratory, Louis Stokes Cleveland Department of Veterans Affairs Medical Center and CASE Medical School, Cleveland, Ohio 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: Robert L
authors.initials: RL
authors.lastname: Tomsak
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Jacobs
mesh_terms: D000328:Adult; D003290:Convergence, Ocular / Q000502:physiology; D004172:Diplopia / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009039:Motion Perception; D009759:Nystagmus, Pathologic / Q000601:surgery*; D009801:Oculomotor Muscles / Q000601:surgery*; D010468:Perceptual Disorders / Q000503:physiopathology*; D013285:Strabismus / Q000601:surgery*; D013710:Tendons / Q000601:surgery*; D015348:Vision, Binocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology*