Effect of Vertical Displacement of Bilateral Horizontal Muscles in AV Syndrome

We reviewed 20 cases for the surgical effect of the vertical transposition of the horizontal rectus muscle for AV syndrome without significant oblique dysfuction. We performed vertical tranposition of the horizontal rectus muscle with standard recession and resection procedure and followed up at least six months. Sixteen cases were V syndrome and four cases were A syndrome. Medial rectus was moved toward the apex of the A or V, and the lateral rectus was moved to the opposite side of the apex of the A or V. The amount of transposition was adjusted according to the amount of vertical incomitance. If the vertical incomitance was 10delta, 15delta, 20deltaand 25delta, vertical transposition of rectus muscle was 1/4 TW[tendon width], 1/2 TW, 3/4 TW amd 1 TW, respectively. We achieved an average of 12.9deltareduction by 1/4 TW transposition, 14.4deltareduction by 1/2 TW transposition, 13.3delta reduction by 3/4 TW transposition, 19.0deltareduction by 1 TW transposition. We also achieved an average of 5.2delta/mm effect by 1/4 TW transposition, 2.9delta/mm effect by 1/2 TW transposition, 2.4 delta/mm effect by 3/4 TW transposition, 1.9delta/mm effect by 1 TW transposition. The vertical transposition of the horizontal rectus muscle for AV syndrome without significant oblique dysfuction showed good result and the amount of correction per mm of vertical transposition seemed to decrease as the amount of transposition increased, even though the total amount of correction showed a trend toward increasing [Fig.1, 2].

Treatment of AV Syndrome

In order to study the surgical of the vertical transposition of the horizontal rectus muscles for AV syndrome, we reviewed 32 cases of AV syndrome not showing significant oblique dysfunction in the department of Pediatric Ophthalmology in Seoul National University from 1986 to 1992. We performed half-tendon width vertical transposition of the horizontal rectus muscles with standard horizontal recession and resection procedure. The subgroups of AV syndrome were consisted of A esotropia 17 cases, A exotropia in 5 cases, V esotropia in 1 case, and V exotropia in 9 cases. The preoperative vertical incomitance of 18.7PD (average) was changed to 1.9PD postoperatively, so 16.8 PD (89.8%) of vertical incomitance was corrected. The AV pattern was eliminated in 31 cases (96.9%) except one. The mean follow-up period was 17.8 months.

Treatment of AV Syndrome

In order to study the surgical of the vertical transposition of the horizontal rectus muscles for AV syndrome, we reviewed 32 cases of AV syndrome not showing significant oblique dysfunction in the department of Pediatric Ophthalmology in Seoul National University from 1986 to 1992. We performed half-tendon width vertical transposition of the horizontal rectus muscles with standard horizontal recession and resection procedure. The subgroups of AV syndrome were consisted of A esotropia 17 cases, A exotropia in 5 cases, V esotropia in 1 case, and V exotropia in 9 cases. The preoperative vertical incomitance of 18.7PD (average) was changed to 1.9PD postoperatively, so 16.8 PD (89.8%) of vertical incomitance was corrected. The AV pattern was eliminated in 31 cases (96.9%) except one. The mean follow-up period was 17.8 months.

The Effect of Vertical Transposition of Horizontal Muscles on Vertical Deviation Associated with Horizontal Strabismus

The authors performed vertical transposition of the horizontal rectus muscles during monocular recession-resection surgery to correct the comitant vertical deviation associated with the horizontal strabismus. When the eye was hypertropic, infratransposition of horizontal rectus muscles was performed and when the eye was hypotropic, supratransposition of the insertions of the horizontal muscles was performed. For vertical strabisumus with 4 delta-12 delta(mean 7.7 delta) angle deviation, each medial and lateral rectus muscles were vertically transposed 2mm-4.5mm(mean 3.1mm) in 51 eyes. Fourty four eyes(86.3%) were vertically aligned, 4 eyes(7.8%) were undercorrected, and 3 eyes(5.9%) were overcorrected with 19.1 months of follow-up periods in average. By one millimeter vertical transposition of horizontal recti, vertical deviation was corrected by 1.21 delta in average. The vertical transposition of horizontal recti can be an effective method for correcting vertical deviation associated with horizontal strabismus not associated with any cyclovertical muscle dysfunction.

The Effect of Vertical Transposition of Horizontal Muscles on Vertical Deviation Associated with Horizontal Strabismus

The authors performed vertical transposition of the horizontal rectus muscles during monocular recession-resection surgery to correct the comitant vertical deviation associated with the horizontal strabismus. When the eye was hypertropic, infratransposition of horizontal rectus muscles was performed and when the eye was hypotropic, supratransposition of the insertions of the horizontal muscles was performed. For vertical strabisumus with 4 delta-12 delta(mean 7.7 delta) angle deviation, each medial and lateral rectus muscles were vertically transposed 2mm-4.5mm(mean 3.1mm) in 51 eyes. Fourty four eyes(86.3%) were vertically aligned, 4 eyes(7.8%) were undercorrected, and 3 eyes(5.9%) were overcorrected with 19.1 months of follow-up periods in average. By one millimeter vertical transposition of horizontal recti, vertical deviation was corrected by 1.21 delta in average. The vertical transposition of horizontal recti can be an effective method for correcting vertical deviation associated with horizontal strabismus not associated with any cyclovertical muscle dysfunction.