Karen Hendler

Isolated Y-Splitting and Recession of the Lateral Rectus Muscle in Patients with Exo-Duane Syndrome

Purpose: Weakening of both horizontal rectus muscles is performed for patients with Duane syndrome and significant misinnervation of the lateral rectus (LR) muscle resulting in strabismus, limitation to ocular rotations, and globe retraction. In patients with severe up-/downshoots, a Y-splitting of the LR is often recommended. The purpose of this study was to evaluate the efficacy of isolated unilateral LR recession-Y splitting in exo-Duane patients with limitation to adduction and up-/downshoots. Methods. Retrospective review of the records of consecutive patients with exo-Duane syndrome and up/down-shoots who underwent isolated Y-splitting-recession of the affected LR. Results: The records of 10 patients were reviewed (mean age at surgery 23 ± 21 years). The Y-split was performed 10 mm posterior to the insertion and was combined with a mean LR recession of 8.7 ± 2.9 mm. Torticollis decreased from 12.7 ± 4.4° to 4.8 ± 5.3° (P = 0.003). Exotropia improved from 18.4 ± 7.3 to 6.2 ± 5.9 PD postoperatively (P < 0.001). Exotropia in contralateral gaze improved from 33.7 ± 11.8 to 18.7 ± 18.1 PD postoperatively (P = 0.09). No significant postoperative changes in esotropia in ipsilateral gaze, vertical deviations, or ocular rotations in adduction or abduction were observed. Downshoots were significantly decreased (P = 0.01), and there was a trend toward improvement of upshoots (P = 0.07). There were no overcorrections, although 3 patients required additional LR weakening and transposition. Conclusions: LR Y-splitting–recession improves ocular alignment, torticollis, and up-/downshoots. LR recession improves ocular alignment and torticollis, while the addition of a Y-split procedure improves up-/downshoots.

Adjustable Augmented Rectus Muscle Transposition Surgery with or Without Ciliary Vessel Sparing for Abduction Deficiencies

Abstract Background: Vertical rectus transposition (VRT) is useful in abduction deficiencies. Posterior fixation sutures enhance the effect of VRT, but usually preclude the use of adjustable sutures. Augmentation of VRT by resection of the transposed muscles allows for an adjustable technique that can reduce induced vertical deviations and overcorrections. Methods: We retrospectively reviewed the records of all patients undergoing adjustable partial or full tendon VRT augmented by resection of the transposed muscles. Ciliary vessels were preserved in most of the patients by either splitting the transposed muscle or by dragging the transposed muscle without disrupting the muscle insertion. Results: Seven patients with abducens palsy and one with esotropic Duane syndrome were included. Both vertical rectus muscles were symmetrically resected by 3–5 mm. Preoperative central gaze esotropia of 30.6 ± 12.9Δ (range, 17–50Δ) decreased to 10.6 ± 8.8Δ (range, 0–25Δ) at the final visit (p = 0.003). Three patients required postoperative adjustment by recession of one of the transposed muscles due to an induced vertical deviation (mean 9.3Δ reduced to 0Δ), coupled with overcorrection (mean exotropia 11.3Δ reduced to 0 in two patients and exophoria 2Δ in one patient). At the final follow-up visit 3.8 ± 2.6 months postoperatively, one patient had a vertical deviation <4Δ, and none had overcorrection or anterior segment ischemia. Three patients required further surgery for recurrent esotropia. Conclusions: Augmentation of VRT by resection of the transposed muscles can be performed with adjustable sutures and vessel-sparing technique. This allows for postoperative control of overcorrections and induced vertical deviations as well as less risk of anterior segment ischemia.

Does inferior oblique recession cause overcorrections in laterally incomitant small hypertropias due to superior oblique palsy

Aim To evaluate the effects of inferior oblique muscle recession (IOR) in cases of laterally incomitant hypertropia <10 prism dioptres (PD) in central gaze thact 2t are clinically consistent with superior oblique palsy (SOP). Methods We retrospectively reviewed patients with SOP and hypertropias <10 PD in central gaze who underwent graded IOR. Primary outcomes were reduction of lateral incomitance and number of overcorrections in central gaze. Results Twenty-five patients were included. Mean follow-up was 13.8 months (range 1.4–66). Mean central gaze hypertropia decreased from 5.6±2.1 to 0.2±1.6 PD (p<0.001). Contralateral gaze hypertropia decreased from 15.9±7.6 to 2.3±3.3 PD (p<0.001). Lateral incomitance (central vs contralateral gaze) was 10.3±6.9 PD preoperatively and 2.0±3.0 PD postoperatively (p<0.001). There were two patients overcorrected in central gaze, and one patient overcorrected in downgaze. One patient necessitated further surgery for overcorrection. Conclusions Although small hypertropias can be treated with prisms or small, adjustable inferior rectus recessions, IOR collapses incomitance without causing much overcorrection. IOR is a reasonable treatment for small, laterally incomitant hypertropia due to SOP.

Response to: Isolated Y-splitting and Recession of the Lateral Rectus Muscle in Patients with Exo-Duane Syndrome

We are thankful for the interest of Drs. Sukhija and Kaur in our study on the role of Y-splitting and simultaneous recession of the lateral rectus in Duane retraction syndrome. We truly appreciate their insights. With respect to the amount of recession in our cases, we do not feel that patients with Duane syndrome can be subjected to rules or surgical tables since there are many extrinsic factors to be considered. The amount of recession that is chosen depends on restriction during intraoperative forced duction testing, the amount of co-contraction (determined by the deviation in adduction), and medial rectus muscle abnormalities. In addition to these factors, we agree with Drs. Sukhija and Kaur that an augmentation to typical lateral rectus muscle recession numbers should always be considered in Duane syndrome. For example, there were 3 patients in our study with approximately 25 prism diopters (PD) of exotropia (XT) in primary position (patients 2, 4, and 7). Although patients 4 and 7 underwent similar amounts of surgery (recession of 9 and 8 mm, respectively), patient 2 underwent a recession of 17 mm and was still largely undercorrected. The reason for this is that patient 4 had a large amount of co-contraction as evidenced by the XT in adduction that was not present in patients 4 or 7. The amount of residual face turn in our patients was linked to the amount of postoperative strabismus in primary position. For example, all of the patients who were orthotropic (n1⁄4 4) had complete resolution of their face turn, while those with residual deviations predictably had persistent but smaller amounts of torticollis. With respect to Dr. Sukhija and Kaur’s subjects, we congratulate them on putting together this interesting series of patients. We have noted that at least one of their patients may not have been fusing postoperatively if they had no head turn with a deviation of 10 PD of XT in primary position. In addition, one of their patients had an 8-degree face turn with no strabismus in primary position. It is unclear what would be driving this face turn unless this was a case of bilateral Duane syndrome. Interestingly, if the mean amount of PD/mm correction in this surgery is compared, their group was corrected 2.19 PD/mm while our group was only corrected 1.4 PD/mm. If we had used their surgical numbers, 100% of our patients would be undercorrected. This discrepancy further demonstrates the variability in Duane syndrome patients and that every case must be considered as a novel situation in which the deviation, face turn, restriction, and co-contraction must be considered. We agree that simple Y-splitting without recession is not sufficient for patients with an XT in primary position. However, splitting the lateral rectus may be sufficient to reduce abnormal vertical movements in patients with no deviation in primary position.