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.
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.
Wang
Zhong I
ZI
Daroff-Dell'Osso Ocular Motility Laboratory, Louis Stokes Cleveland Department of Veterans Affairs Medical Center and CASE Medical School, Cleveland, Ohio 44106, USA.
Dell'Osso
Louis F
LF
Tomsak
Robert L
RL
Jacobs
Jonathan B
JB
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*