Quantitative Intraoperative Torsional Forced Duction Test

Abstract

Purpose We developed a method for quantifying intraoperative torsional forced ductions and validated the new test by comparing patients with oblique dysfunction and controls. Design Comparative case series Subjects We studied 33 eyes with oblique dysfunction (9 presumed congenital superior oblique palsy (SOP), 13 acquired SOP, 7 Brown syndrome, and 4 Inverted Brown syndrome) and 31 controls. We also studied maximal excyclorotation after superior oblique (SO) disinsertion in 6 eyes and maximal incyclorotation after inferior oblique (IO) disinsertion in 2 eyes. Methods Under deep general anesthesia, the 12 and 6 o’clock positions at the limbus were marked and the globe was maximally excyclorotated and incyclorotated without retroplacement until the first resistance was felt, and the angle of rotation (in degrees) was read on a Mendez ring by the surgeon. A photograph was taken in each position to be read by a masked observer. Main outcome measures Maximal excyclorotation and maximal incyclorotation in each oblique dysfunction and in controls, by both surgeon’s report and photographic assessment. We duplicated the photographs to evaluate test-retest reliability and to evaluate agreement between the surgeon’s assessments and photographic assessment. Results Surgeon’s assessment revealed greater maximal excyclorotation in presumed congenital SOP than controls (median, 40 degrees versus 30 degrees). Maximal excyclorotation in acquired SOP was similar to controls (30 degrees in both). Eyes with Brown syndrome and Inverted Brown syndrome had lower maximal excyclorotation than controls (10 degrees and 20 degrees versus 30 degrees, respectively). Maximal incyclorotation in inverted Brown syndrome was lower than controls (12.5 degrees versus 30 degrees) whereas it was similar to controls in presumed congenital SOP, acquired SOP and Brown syndrome (30 degrees in each condition). Median maximal excyclorotation after SO disinsertion was 62.5 degrees and maximal incyclorotation after IO disinsertion was 60 degrees. Photographic assessment yielded essentially identical findings to the surgeon’s report. Test-retest reliability of the photographic reading was excellent and agreement between the surgeon’s report and the photographic reading was also excellent (95% Limits of agreement; 4.4 and 11.6, Intraclass correlation coefficient; 0.97 and 0.82, respectively). Conclusions The new torsional forced duction test enables quantitative assessment of superior oblique and inferior oblique tightness and laxity.

Dose Effect and Stability of Postoperative Cyclodeviation After Adjustable Harada-Ito Surgery

“…If adjusted, the noose was slid up or down and the amount of advancement or recession was estimated in increments of 0.5mm. To avoid large over- or undercorrections, intraoperative monitoring of the torsional alignment 7 was used in more recent years of the study. Our rationale for using both intraoperative monitoring and postoperative adjustment was that intraoperative monitoring does not allow fine tuning of the alignment to the nearest 1–2° and does not account for muscle tone in the awake patient.…”

Adjustable Bilateral Superior Oblique Tendon Advancement for Bilateral Fourth Nerve Palsy

“…11, 12 Forced ductions, including Guyton’s exaggerated traction test 13 and the torsional forced duction test, 14 were performed on both eyes to assess superior oblique tendon laxity. A silk traction suture was placed at 12 o’clock through partial scleral thickness at the limbus, and a superior temporal fornix conjunctival incision was made with Westcott scissors through Tenon’s capsule.…”

“…The superior oblique tendon was then cut from the sclera. The decision whether to resect part of the tendon and how much to resect (5 mm to 7 mm) was made according to the surgeon’s judgment regarding the laxity of the tendon on the Guyton exaggerated traction test 13 and the torsional forced duction test 14 at the start of the procedure and how far the tendon could be pulled down toward the lateral rectus. A 6-0 double-armed Vicryl suture was imbricated in a double-locking manner at the end of the tendon fibers (or further back if a resection was planned).…”

“…Positioning of the tendon relative to the superior border of the lateral rectus muscle (Figure 1) was determined by intraoperative monitoring of torsion using the two blue dots placed at the limbus at the start of surgery. 14 To try to reduce the incidence of overcorrections and postoperative Brown syndrome, intraoperative traction testing was performed to confirm that each eye could still extort at least 10 degrees and the inferior limbus of each eye could still elevate well above the intercanthal line. An additional silk traction suture was placed through partial scleral thickness just posterior to the new insertion of the superior oblique fibers.…”

Management of Panfacial Fracture

“…The forced duction test will also need to be performed to verify freely moving orbital cone contents. 21 This will all need to be done in anticipation of closure. The closure of the midface is a very important aspect of panfacial trauma management, so even part of the opening has to do with the anticipation of the closure.…”