Exotropic Duane Syndrome Research Articles

The presence of anomalous extraocular bands in Duane retraction syndrome

To determine the prevalence of anomalous extraocular bands in patients who underwent surgery for Duane syndrome and to compare the clinical findings in patients with and without bands. Thirty-one patients with Duane syndrome who had their first surgery on rectus muscles to correct the primary deviation and abnormal head posture were included in this retrospective study. Patients were divided into two groups depending on the identification of anomalous extraocular bands intraoperatively. Baseline clinical characteristics were compared between the groups. A total of 31 patients were included. Anomalous bands were found in 6 of 19 (32%) patients with esotropic Duane syndrome and 9 of 12 (75%) with exotropic Duane syndrome (P=0.02). In esotropic Duane syndrome, the bands were localized under the medial rectus muscle in 5 patients and under the lateral rectus muscle in 1 patient. All of the bands in patients with exotropic Duane syndrome were under the lateral rectus muscle. The amount of preoperative primary deviation, globe retraction, and up- or downshoot were similar between groups. All of the bands had distinct tight insertion on the sclera, requiring a sharp dissection for disinsertion. In 7 cases, the anomalous band was a translucent structure that could be identified under the surgical microscope as scleral indentation during forced duction testing. Histological examination of 6 cases revealed only fibrous tissue in 4 and accompanying striated muscle tissue in 2 patients. The present study highlights the incidence of anomalous bands in Duane syndrome.Repeating forced duction testing after disinsertion of the affected muscle and excision of the anomalous band is helpful for intraoperative identification of these structures.

Surgical outcome of exotropic Duane syndrome

ABSTRACTPurpose: To evaluate the surgical outcome of exotropic Duane syndrome and the factors that can influence the outcome.Methods: A retrospective study was performed on patients who had surgery for exotropic Duane syndrome with a minimum follow-up of 3 months. The ocular motility, the angles of deviation, the presence of abnormal head turn or overshoots, the surgical procedures performed, and their outcome were analyzed.Results: Sixty-seven patients were identified (mean age, 11.3 years). In unilateral cases with exotropia <25 PD (n = 28), ipsilateral lateral rectus (LR) recession was performed in all cases, and orthophoria was achieved in 25 patients (89.3%). In unilateral cases with angle ≥25 PD, ipsilateral LR recession was performed in 13 patients, bilateral symmetrical LR recession in eight patients, and unilateral LR recession and medial rectus (MR) resection in seven patients. Sequential contralateral LR recession for undercorrection was performed in seven patients. The success rate was highest in those who had unilateral LR recession and MR resection (66.7%). An increase in face turn occurred in 6 of 15 patients (40%) who had a simultaneous or sequential bilateral LR recession. In bilateral Duane syndrome, bilateral LR recession was performed in 10 patients, and was combined with ipsilateral MR resection in two patients with a success rate of 75%. Higher success rate was associated with young age at surgery (P = .03) and smaller angle of deviation (p = .04). The mean follow-up was 6.3 months.Conclusions: Surgical results in exotropic Duane syndrome are better in small angles of deviation and in younger age groups.

Advances in research of synergistic divergence

Synergistic divergence is a rare condition characterized by complete absence of adduction that is associated with simultaneous abduction of the affected eye on attempted adduction. This causes the affected eye to move further into abduction on gaze to the normal side and results in extreme divergence of both eyes. It is sometimes referred to as exotropic Duane syndrome with synergistic divergence (type 4 Duane syndrome) or congenital fibrosis syndrome with synergistic divergence. Diseases combined with synergistic divergence fall within the category of congenital cranial dysinnervation disorders (CCDDs). The ocular associations reported with synergistic divergence are uncommon and include Horner syndrome, ocular albinism, foveal hypoplasia, Goldenhar syndrome and pupillary abnormalities. MRI and electro-oculographic study suggested that this is the result of CCDDs. Various surgical techniques have been tried in individual cases including large recession of the lateral rectus muscle, lateral rectus muscle extirpation, large resection of the medial rectus (MR) muscle, weakening procedures of the oblique muscles, combination of lateral rectus orbital wall fixation with MR resection, but further investigations with large-scale samples are needed. Recent research advances in the definition, etiology, and treatment of synergistic divergence are reviewed in this article. (Chin J Ophthalmol, 2019, 55:63-67).

The pursuit of stereopsis

Pediatric ophthalmologists are increasingly expected to promote, preserve, and restore binocular vision. Clinical studies on restoring alignment and stereopsis in the management of amblyopia, esotropia, exotropia, and complex strabismus are reviewed from the perspective of the author's published work and personal experiences. Treatment of amblyopia by means of optical rehabilitation, occlusion, or penalization has been reinforced by medical treatment and perceptual training with monocular or binocular video games. Studies indicate that early management of esotropia and alignment within 8Δ is required for regaining stereopsis. In the surgical management of intermittent exotropia, distance stereopsis by Frisby Davis Distance stereotest can predict better stereopsis, with patients having preoperative distance stereopsis of <70 arcsec less likely to improve after surgery. The surgeon's armamentarium for correcting alignment and restoring binocular vision include procedures such as adjustable, partial vertical rectus muscle transposition in cases of exotropic Duane syndrome and lateral rectus palsy, periosteal fixation of the globe or of the lateral rectus muscle, and medial transposition of the split lateral rectus muscle. The goal for present-day strabismologists is not merely to correct strabismus but also to achieve alignment of eyes in time to ensure normal development of stereopsis in children and to restore alignment and stereopsis in adults.

Exotropic Duane syndrome with synergistic divergence and no mutations in COL25A1

Typical Duane retraction syndrome, a common form of congenital cranial dysinnervation disorder (CCDD), is rarely due to a monogenic mutation. However, the unusual form of exotropic Duane syndrome with synergistic divergence was recently associated with bi-allelic mutations in the gene COL25A1, raising the possibility that this particular Duane syndrome phenotype could be a monogenic recessive CCDD. To explore this possibility, we tested 4 consecutive unrelated subjects with the diagnosis for COL25A1 mutations. None harbored pathogenic variants, evidence that exotropic Duane syndrome with synergistic divergence is notspecifically caused by mutations in the gene.

Accessory fibrotic lateral rectus muscles in exotropic Duane syndrome with severe retraction and upshoot

FIGURE 1. Final position of lateral rectus (LR) and accessory bands. A 3.5-year-old boy presented at the University of California Los Angeles–Olive View Hospital with abnormal eye movements present since birth. His parents noticed that his left eye always appeared smaller than his right eye and that he had a right head turn. On examination, the patient demonstrated a 5 right head turn. In forced primary position, he had an exotropia of 6. He had 2 limitation to adduction and abduction and13 overelevation in adduction (upshoot) in the left eye. The decision was made to perform surgery consisting of a lateral rectus recession with Y-splitting for presumed exotropic Duane syndrome with a significant upshoot. Preoperative forced duction testing revealed moderate restriction to adduction and no restriction to abduction. The surgical video demonstrates the presence of 2 accessory bands posterior to the lateral rectus muscle. All 3 structures (the lateral rectus and the 2 accessory bands) were recessed to 17 mm from the limbus in a V-shaped configuration (Figures 1 and 2). At postoperative month 1, the patient was orthotropic in primary position, and his upshoot had resolved. His adduction improved to 1 but his abduction worsened to 3. First reported in 1893 by Nussbaum, accessory muscles have been well described in disorders such as Duane syndrome and congenital fibrosis of the extraocular muscles. They should be suspected in patients with atypical patterns of restrictive strabismus, globe retraction in directions other than adduction, or in patients with severe upor downshoots. Lueder described 3 types of accessory bands in his 2002 review: (1) structures arising from extraocular muscles and inserting in abnormal locations, (2) fibrous

Isolated lateral rectus recession with Y splitting versus anchoring of the lateral rectus muscle in patients with exotropic Duane syndrome

To compare the outcome of two surgical procedures used to treat up- and downshoots in Duane retraction syndrome associated with exotropia. The medical records of patients with exotropic Duane retraction syndrome seen at a single tertiary care facility from 2009 to 2012 were retrospectively reviewed. Patients were divided into two groups, one comprising patients treated with Y splitting and recession of the lateral rectus muscle; the other, patients treated with anchoring of the lateral rectus muscle to the lateral palpebral ligament. Surgical outcomes were compared in terms of deviation, head turn, up- and downshoot, and duration of surgery. A total of 15 patients were included, 7 treated by Y splitting and recession and 8 by anchoring of the lateral rectus muscle. Both groups were comparable in terms of age, sex, laterality, best-corrected visual acuity, mean deviation in primary position, and preoperative head turn to the affected side. Torticollis decreased from 27.9° ± 6.4° to 2.6° ± 4.4° in the Y-split group and from 22.5° ± 5.9° to 1.6° ± 3.1° in the anchoring group (P < 0.001 [95% CI]). Exotropia decreased from 26.4(Δ) ± 5.6(Δ) to 2.28(Δ) ± 4.07(Δ) in the Y-split group and 26.9(Δ) ± 5.3(Δ) to 1.5(Δ) ± 6.88(Δ) in the anchoring group (P < 0.001 [95% CI]). The up- and downshoots decreased markedly in the both groups (P = 0.7 for upshoots and P = 1 for downshoots). The mean operating time was 15.3 ± 2.0 minutes for Y splitting plus recession and was 8.3 ± 1.8 minutes for anchoring. In our patient cohort, the two procedures yielded comparable results in terms of the correction of the horizontal position deviation, head posture, and up- and downshoots.

Profound weakening of the lateral rectus muscle with attachment to lateral canthal tendon for treatment of exotropic Duane syndrome

An 8-year-old girl with exotropic Duane syndrome presented with upshoot, downshoot, and globe retraction in attempted adduction. To correct the alignment and treat the secondary aberrant movements, we weakened the lateral rectus muscle using a new surgical technique. In this approach, the lateral rectus muscle of the involved eye was disinserted and then attached to the lateral canthal tendon using nonabsorbable sutures. At the 3-week return visit, the patient was orthotropic in straight-ahead gaze with slightly improved adduction and negligible upshoot, downshoot, and globe retraction.

Lateral rectus muscle disinsertion and reattachment to the lateral orbital wall in exotropic Duane syndrome: a case report

IntroductionThe surgical correction of anomalous movement such as upshoot in Duane syndrome is challenging. Lateral rectus muscle disinsertion and reattachment to the lateral orbital wall is a new approach used to minimize or eliminate the effects of co-contraction including globe retraction, palpebral fissure narrowing and anomalous vertical movement.Case presentationWe report a case of a 7-year-old boy who underwent this procedure for severe upshoot, globe retraction and exotropia in the left eye due to Duane syndrome. The patient achieved satisfactory ocular alignment following surgery. Upshoot and globe retraction were substantially improved.ConclusionLateral rectus muscle disinsertion and reattachment to the lateral orbital wall is a safe and effective procedure for weakening of the anomalous lateral rectus muscle in Exotropic Duane Syndrome.