Special clinical features with a novel mutation site of CHN1 gene in a Chinese family with Duane retraction syndrome.

PURPOSE: This study is to describe the special clinical and genotypic features of a Chinese family with variant types of Duane retraction syndrome and to present our experience on managing these cases. METHODS: Four individuals from one family were reviewed by ophthalmologic examinations, in which two affected and two unaffected individuals were revealed. MRI scans were performed on the two patients. Relevant gene mutations were screened by the next-generation sequencing technology and confirmed by Sanger sequencing technology. RESULTS: The six-year-old proband presented with special clinical features of severe horizontal gaze dysfunction, exotropia and mild scoliosis. His mother showed significantly limited binocular abductions, with retraction of eyeballs in adduction. From MRI scans, abducens nerves were not observed in both patients and the oculomotor nerve was slightly thin in the proband. The proband and his mother shared the same CHN1 gene mutation site (c. 62A>G; p.Y21C). Strabismus surgery was performed on the proband to correct the primary gaze exotropia.(NM_001822: exon3 or NM_001025201: exon4: c. 62A>G; p.Y21C). CONCLUSIONS: A novel CHN1 gene mutation was revealed from a Chinese family with Duane retraction syndrome. Remarkably, the proband and his mother presented different clinical features of ocular motility disorder. Strabismus correction surgery and amblyopia training helped to improve the appearance and visual function of the proband.

SALL4 Phenotype in Four Generations of One Family: An Interplay of the Upper Limb, Kidneys, and the Pituitary.

INTRODUCTION: The SALL4 gene encodes a transcription factor that is essential for early embryonic cellular differentiation of the epiblast and primitive endoderm. It is required for the development of neural tissue, kidney, heart, and limbs. Pathogenic SALL4 variants cause Duane-radial ray syndrome (Okihiro syndrome), acro-renal-ocular syndrome, and Holt-Oram syndrome. We report a family with vertical transmission of a SALL4 pathogenic variant leading to radial hypoplasia and kidney dystopia in several generations with additional growth hormone deficiency (GHD) in the proband. CASE PRESENTATION: Our male proband was born at the 39th week of gestation. He was born small for gestational age (SGA; birth weight 2,550 g, -2.2 SDS; length 47 cm, -2.0 SDS). He had bilateral asymmetrical radial ray malformation (consisting of radial hypoplasia, ulnar flexure, and bilateral aplasia of the thumb) and pelvic kidney dystopia, but no cardiac malformations, clubfoot, ocular coloboma, or Duane anomaly. He was examined for progressive short stature at the age of 3.9 years, where his IGF-1 was 68 µg/L (-1.0 SD), and growth hormone (GH) after stimulation 6.2 µg/L. Other pituitary hormones were normal. A brain CT revealed normal morphology of the cerebral midline and the pituitary. He had a dental anomaly - a central mandibular ectopic canine. MRI could not be done due to the presence of metal after multiple corrective plastic surgeries of his hands. His mother's and father's heights are 152.3 cm (-2.4 SD) and 177.8 cm (-0.4 SD), respectively. His father has a milder malformation of the forearm. The affected paternal grandfather (height 164 cm; -2.3 SD) has a radial ray defect with missing opposition of the thumb. The family reports a similar phenotype of radial dysplasia in the paternal grandfather's mother. The proband started GH therapy at age 6.5 years when his height was 109 cm (-2.8 SDS) and he experienced catch-up growth as expected in GHD. Puberty started spontaneously at the age of 12.5 years. At age 13, his height was 158.7 cm (-0.2 SDS). Whole-exome sequencing revealed a nonsense variant in the SALL4 gene c.1717C>T (p.Arg573Ter) in the proband, his father, and paternal grandfather. CONCLUSION: This is the first observation of a patient with a congenital upper limb defect due to a pathogenic SALL4 variant who has isolated GHD with no apparent cerebral or facial midline anomaly and has been successfully treated with growth hormone.

Two novel CHN1 variants identified in Duane retraction syndrome pedigrees disrupt development of ocular motor nerves in zebrafish.

Duane retraction syndrome (DRS) is a rare congenital eye movement disorder causing by the dysplasia of abducens nerve, and has highly variable phenotype. MRI can reveal the endophenotype of DRS. Most DRS cases are sporadical and isolated, while some are familial or accompanied by other ocular disorders and systemic congenital abnormalities. CHN1 was the most common causative gene for familial DRS. Until now, 13 missense variants of CHN1 have been reported. In this study, we enrolled two unrelated pedigrees with DRS. Detailed clinical examinations, MRI, and the whole exome sequencing (WES) were performed to reveal their clinical and genetic characteristics. Patients from pedigree-1 presented with isolated DRS, and a novel heterozygous variant c.650 A > G, p. His217Arg was identified in CHN1 gene. Patients from pedigree-2 presented with classic DRS and abnormalities in auricle morphology, and the pedigree segregated another novel heterozygous CHN1 variant c.637 T > C, p. Phe213Leu. A variety of bioinformatics software predicted that the two variants had deleterious or disease-causing effects. After injecting of two mutant CHN1 mRNAs into zebrafish embryos, the dysplasia of ocular motor nerves (OMN) was observed. Our present findings expanded the phenotypic and genotypic spectrum of CHN1 related DRS, as well as provided new insights into the role of CHN1 in OMN development. Genetic testing is strongly recommended for patients with a DRS family history or accompanying systemic congenital abnormalities.

[Novel frameshift mutations in SALL4 in two Chinese families with Okihiro syndrome].

In the present study, clinical manifestations of two Chinese Okihiro syndrome families were analyzed, and genetic detections were performed on the two probands by exome sequencing and verified by Sanger sequencing for family members to determine the biological pathogenesis. Prenatal diagnoses were provided for three high-risk fetuses. The affected members exhibited a wildly spectrum of phenotypes, including ultrasound abnormalities of skeletal system (radius deformity and abnormal posture), and cardiac system (persistent common arterial trunk and ventricular septal defect) in the prenatal period of family 1, the severe phenotypes (grossly shortened and deformed forearm, Duane's anomaly and hearing loss), and the mild ones (usually only thenar dysplasia, or short radius styloid process). Two SALL4 variants, c.844delC p.(Q282Kfs*8) and c.2210delG p.(G737Vfs*23), have been identified respectively in two probands, and c.2210delG of SALL4 gene was unreported previously. The two variants were verified in all affected individuals, not in normal family members. Genotyping results of three fetuses indicated that one fetus was normal, and the two fetuses with heterozygous variation were affected. The two variants of SALL4 gene, c.844delC p.(Q282Kfs*8) and c.2210delG p.(G737Vfs*23), were the molecular pathological cause of Okihiro syndrome in the present study and enriched the spectrum of SALL4 variants. Our study provides accurate prenatal genetic diagnosis for the two families to avoid the birth of affected children.

Síndrome de Wildervanck: reporte de un caso clínico / Wildervanck syndrome: clinical case report

El síndrome de Wildervanck (cérvico-óculo-acústico) es una patología muy rara, caracterizada por la tríada clásica de fusión de vértebras cervicales o anomalía de Klippel-Feil, síndrome de Duane (paresia del VI par craneal) e hipoacusia. Se han descrito, además, otras afecciones a nivel vascular, cardíaco y musculoesquelético. En este caso clínico, describimos a una paciente que cumple la tríada cardinal, además de presentar datos clínicos adicionales que no han sido reportados con anterioridad, lo cual contribuye a la ampliación del fenotipo de la enfermedad. Asimismo, realizamos una revisión de la literatura respecto a este síndrome

Wildervanck syndrome (also known as cervico-oculo-acoustic dysplasia) is a very rare disease, characterized by the typical triad of cervical vertebral fusion or Klippel-Feil anomaly, Duane syndrome (paresis of the sixth cranial nerve), and hearing loss. Other vascular, cardiac, and musculoskeletal conditions have also been described. In this case report, we describe a patient who met the cardinal triad and also presented additional clinical data that have not been previously reported, which contribute to broadening the disease phenotype. We have also reviewed the bibliography related to this syndrome.

Modified Nishida's procedure for esotropia in Duane syndrome associated with Goldenhar syndrome.

Modified Nishida's procedure (no split, no tenotomy transposition) has been recently described as an effective surgery for monocular elevation deficiency and for traumatic rupture of the inferior rectus muscle. We report the modified Nishida's procedure combined with medial rectus muscle recession for the treatment of esotropia in unilateral Duane syndrome associated with Goldenhar syndrome. Following the surgery and over a 1-year follow-up period, the patient was orthophoric at distance and near, abduction improved, and the abnormal head position resolved.

Is the Pupil Involved in Duane Syndrome? Static and Dynamic Pupillometry Characteristics.

Objectives: Duane syndrome (DS) is typically characterized by abduction and/or adduction deficiency accompanied by eyelid and ocular motility disturbances. Maldevelopment or absence of the sixth nerve has been shown to be the causative factor. The aim of the present study was to investigate static and dynamic pupillary characteristics in patients with DS and compare the results with those of healthy eyes. Materials and Methods: Patients with unilateral isolated DS and no history of ocular surgery were enrolled in the study. Healthy subjects with a best corrected visual acuity (BCVA) of 1.0 or higher were assigned to the control group. All subjects underwent complete ophthalmological examination and pupillometry measurements (MonPack One, Vision Monitor System, Metrovision, Perenchies, France) including static and dynamic pupil evaluation. Results: A total of 74 patients (22 with DS and 52 healthy subjects) were included in the study. The mean age of the DS patients and healthy subjects was 11.05±5.19 and 12.54±4.05 years, respectively (p=0.188). There was no difference in sex distribution (p=0.502). Mean BCVA differed significantly between eyes with DS and healthy eyes, and between healthy eyes and the fellow eyes of DS patients (p<0.05). No significant difference was found in any static or dynamic pupillometry parameters (p>0.05 for all). Conclusion: In the light of the results of the present study, the pupil seems to be not involved in DS. Larger studies including more patients with different types of DS in different age groups or comprising patients with non-isolated DS may reveal different findings.

Orbital leiomyoma presenting as inverse globe retraction syndrome: a unique presentation of a rare disease.

Inverse globe retraction syndrome is a rare ocular motility disorder characterized by limited abduction, with globe retraction and up- or downshoots on attempted abduction, differentiating it from globe retraction due to Duane retraction syndrome, seen on attempted adduction. It can be congenital or acquired. We report the case of a 3-year-old girl who presented with classical features of inverse globe retraction syndrome secondary to an underlying orbital tumor involving the medial rectus muscle. Incisional biopsy confirmed the diagnosis of a leiomyoma. At 10 months' follow-up, vision, ocular alignment, and ocular motility had improved.

Wildervanck syndrome: clinical case report. / Síndrome de Wildervanck: reporte de un caso clínico.

Wildervanck syndrome (also known as cervico-oculo-acoustic dysplasia) is a very rare disease, characterized by the typical triad of cervical vertebral fusion or Klippel-Feil anomaly, Duane syndrome (paresis of the sixth cranial nerve), and hearing loss. Other vascular, cardiac, and musculoskeletal conditions have also been described. In this case report, we describe a patient who met the cardinal triad and also presented additional clinical data that have not been previously reported, which contribute to broadening the disease phenotype. We have also reviewed the bibliography related to this syndrome.

El síndrome de Wildervanck (cérvico-óculo-acústico) es una patología muy rara, caracterizada por la tríada clásica de fusión de vértebras cervicales o anomalía de Klippel-Feil, síndrome de Duane (paresia del VI par craneal) e hipoacusia. Se han descrito, además, otras afecciones a nivel vascular, cardíaco y musculoesquelético. En este caso clínico, describimos a una paciente que cumple la tríada cardinal, además de presentar datos clínicos adicionales que no han sido reportados con anterioridad, lo cual contribuye a la ampliación del fenotipo de la enfermedad. Asimismo, realizamos una revisión de la literatura respecto a este síndrome.

Clinical characteristics and surgical approach in Duane retraction syndrome: a study of 691 patients.

PURPOSE: To evaluate the clinical findings of different types of Duane retraction syndrome (DRS). STUDY DESIGN: Retrospective. METHODS: This study was performed on 691 patients with DRS who underwent surgery. Clinical examinations included laterality, abnormal head posture (AHP), corrected distance visual acuity (CDVA), refractive error, amblyopia, deviation, overshoots, and type of surgery. RESULTS: The mean age of patients with DRS was 16.7 ± 12.5 (range 1.0-73) years. The patients included 396 (57.3%) women and 295 (42.7%) men (P < 0.001). DRS type I, was observed in 429 (62.1%), II in 168 (24.3%), III in 88 (12.7%) and IV in 6 (0.9%) patients. Unilateral DRS was observed OS in 628 (90.9%) [471 (%78.9) and OD in 157 (21.1%) eyes (P < 0.001)]. O ther clinical findings were AHP (n = 522, 78.1%), overshoot (n = 236, 34.2%) and amblyopia (n = 118, 17.1%). The prevalence of overshoot in types I, II, and III was 17.5% (75/429), 60.7% (102/168) and 64.8% (57/88), respectively (P < 0.001). The prevalence of amblyopia was significantly lower in patients with AHP (80/522, 15.3%) compared to patients with normal head posture (38/169, 22.5%) (P = 0.023). The mean angle of deviation in the primary position (PP) at distance was 21.7 ± 11.5 △ for esotropic group and 17.8 ± 12.4 △ for exotropic group. Sixty-two (9.0%) patients required second surgery for resolving residual misalignment (1.1 surgeries for each patient). CONCLUSIONS: About two-thirds of DRS patients had AHP, one-third had overshoots, and one-sixth had amblyopia. The results show that different types of DRS are associated with different epidemiological and clinical characteristics.

Hummelsheim procedure combined with medial rectus recession in complete sixth nerve palsy and esotropic Duane Retraction Syndrome.

PURPOSE: To evaluate the effect of half tendon vertical rectus muscle transposition (HVRT) combined with medial rectus muscle recession (MRrec) in complete sixth nerve palsy (CSNP) and esotropic Duane Retraction Syndrome (eDRS). METHODS: A retrospective study of patients with unilateral CSNP or eDRS who underwent HVRT combined with medial rectus recession over the course of 18 years. The patients with previous strabismus surgery and follow up less than 3 months were excluded. Overcorrection was defined as any amount of exotropia, and undercorrection was defined as residual esotropia of ⩾10 prism diopter (PD). RESULTS: A total of 39 patients were enrolled including 22 CSNP and 17 eDRS patients. Esotropia improved from 45.8 ± 22 and 22.5 ± 6.4 PD to 0.8 ± 2.5 and 0.3 ± 1 PD in CSNP group and eDRS group respectively. The angle of face turn improved from 34.3 ± 8.4° and 26.5 ± 9° to 0.6 ± 2.4° and 0.8 ± 1.6° in the CSNP group and eDRS group respectively. Abduction limitation improved from -4.5 ± 0.5 and -4 ± 0 units to -2.9 ± 0.5 and -2.7 ± 0.5 units in CSNP group and eDRS group respectively. No patient developed a new vertical deviation. An overcorrection occurred in one patient of the eDRS group who improved after botulinum toxin injection in the ipsilateral lateral rectus muscle. Undercorrection was seen in two patients. CONCLUSION: HVRT combined with MRrec is an effective procedure to improve esotropia, face turn, and abduction limitation in CSNP and eDRS.

Expanding the Phenotype of the FAM149B1-Related Ciliopathy and Identification of Three Neurogenetic Disorders in a Single Family.

Biallelic truncating FAM149B1 variants result in cilia dysfunction and have been reported in four infants with Joubert syndrome and orofaciodigital syndrome type VI, respectively. We report here on three adult siblings, 18 to 40 years of age, homozygous for the known FAM149B1 c.354_357delinsCACTC (p.Gln118Hisfs*20) variant. Detailed clinical examinations were performed including ocular and gait analyses, skeletal- and neuroimaging. All three patients presented with neurological and oculomotor symptoms since birth and mild skeletal dysplasia in infancy resulting in characteristic gait abnormalities. We document mild skeletal dysplasia, abnormal gait with increased hip rotation and increased external foot rotation, ataxia, variable polydactyly, ocular Duane syndrome, progressive ophthalmoplegia, nystagmus, situs inversus of the retinal vessels, olfactory bulb aplasia, and corpus callosal dysgenesis as novel features in FAM149B1-ciliopathy. We show that intellectual disability is mild to moderate and retinal, renal and liver function is normal in these affected adults. Our study thus expands the FAM149B1-related Joubert syndrome to a mainly neurological and skeletal ciliopathy phenotype with predominant oculomotor dysfunction but otherwise stable outcome in adults. Diagnosis of FAM149B1-related disorder was impeded by segregation of multiple neurogenetic disorders in the same family, highlighting the importance of extended clinical and genetic studies in families with complex phenotypes.

The Rac-GAP alpha2-Chimaerin Signals via CRMP2 and Stathmins in the Development of the Ocular Motor System.

A precise sequence of axon guidance events is required for the development of the ocular motor system. Three cranial nerves grow toward, and connect with, six extraocular muscles in a stereotyped pattern, to control eye movements. The signaling protein alpha2-chimaerin (α2-CHN) plays a pivotal role in the formation of the ocular motor system; mutations in CHN1, encoding α2-CHN, cause the human eye movement disorder Duane Retraction Syndrome (DRS). Our research has demonstrated that the manipulation of α2-chn signaling in the zebrafish embryo leads to ocular motor axon wiring defects, although the signaling cascades regulated by α2-chn remain poorly understood. Here, we demonstrate that several cytoskeletal regulatory proteins-collapsin response mediator protein 2 (CRMP2; encoded by the gene dpysl2), stathmin1, and stathmin 2-bind to α2-CHN. dpysl2, stathmin1, and especially stathmin2 are expressed by ocular motor neurons. We find that the manipulation of dpysl2 and of stathmins in zebrafish larvae leads to defects in both the axon wiring of the ocular motor system and the optokinetic reflex, impairing horizontal eye movements. Knockdowns of these molecules in zebrafish larvae of either sex caused axon guidance phenotypes that included defasciculation and ectopic branching; in some cases, these phenotypes were reminiscent of DRS. chn1 knock-down phenotypes were rescued by the overexpression of CRMP2 and STMN1, suggesting that these proteins act in the same signaling pathway. These findings suggest that CRMP2 and stathmins signal downstream of α2-CHN to orchestrate ocular motor axon guidance and to control eye movements.SIGNIFICANCE STATEMENT The precise control of eye movements is crucial for the life of vertebrate animals, including humans. In humans, this control depends on the arrangement of nerve wiring of the ocular motor system, composed of three nerves and six muscles, a system that is conserved across vertebrate phyla. Mutations in the protein alpha2-chimaerin have previously been shown to cause eye movement disorders (squint) and axon wiring defects in humans. Our recent work has unraveled how alpha2-chimaerin coordinates axon guidance of the ocular motor system in animal models. In this article, we demonstrate key roles for the proteins CRMP2 and stathmin 1/2 in the signaling pathway orchestrated by alpha2-chimaerin, potentially giving insight into the etiology of eye movement disorders in humans.

Superior Rectus Transposition and Medial Rectus Recession for Treatment of Duane Retraction Syndrome and Sixth Nerve Palsy.

Purpose: To evaluate the outcome of augmented superior rectus transposition (SRT) with medial rectus (MR) recession in patients with Duane Retraction Syndrome (DRS) and sixth nerve palsy.Methods: Twenty four patients (16 DRS and 8 sixth nerve palsy) that underwent the procedure were included. The superior rectus muscle was secured, detached, and re-attached to the sclera along the spiral of Tilaux, adjacent to lateral rectus insertion. A non-absorbable augmentation suture was passed through the sclera, 8 mm posterior to the insertion of the lateral rectus.Results: At the last follow-up, the effect of surgery in decreasing esotropia in both groups was significant (P = .001 for DRS group, P = .002 for sixth nerve palsy). In both groups, abduction deficit improved significantly (P < .001 for DRS and P = .008 for sixth nerve palsy). After the surgery, small, asymptomatic vertical deviation in primary position was induced in five patients (20.8%). Post-operatively, none of the patients complained of torsional diplopia. In the 6-month follow-up, compared with the first postoperative visit, an eso-drift at distance or near developed in 11 patients (45.8%). Of the 11 patients with eso-drift, overcorrection (exotropia of 3-14 PD) was present at the first post-operative visit in 5 cases. Four cases showed an exo-drift (2-5 PD) at distance or near over time.Conclusion: SRT with medial rectus recession improves esotropia and abduction limitation without inducing significant vertical deviations and torsional diplopia. Some of the cases that underwent SRT with MR recession may show an eso-drift. The eso-drift can correct initial exotropia in some cases.

Novel finding of atrophic extraocular muscles in Loeys-Dietz syndrome: a case report and review of the literature.

A 19-year-old man with Loeys-Dietz syndrome and right exotropic Duane syndrome after bilateral lateral rectus recessions at age 22 months presented with recurrent progressive exotropia 17 years after his initial surgery. Surgical correction was aborted intraoperatively when extreme atrophy of the right medial rectus, lateral rectus, and superior rectus muscles was observed, later corroborated by orbital magnetic resonance imaging.

Síndrome de pseudo-Duane secundario a Schwannoma de nervio abducens: Reporte de caso y revisión / Pseudo-Duane syndrome secondary to abducens nerve schwannoma: Case report and review

Reporte de caso de síndrome de pseudo-Duane asociado a schwannoma de nervio abducens y neurofibromatosis tipo 2 (NF2). Este síndrome es raro, caracterizado por limitación en abducción, retracción ocular, disminución de hendidura palpebral en abducción y restricción del recto medial ipsilateral en test de ducción forzada. La NF2 es también una enfermedad infrecuente caracterizada por tumores de sistema nervioso central y periférico. Los schwannomas de nervio abducens son también poco frecuentes, y se presentan comúnmente con diplopia. Se revisan brevemente estas enfermedades. Es el primer caso reportado de pseudo-Duane secundario a schwannoma de nervio abducens y NF2 según nuestro conocimiento.

A pseudo-Duane syndrome case associated with abducens nerve schwannoma and neurofibromatosis type 2 (NF2) is presented. This syndrome is a rare disease characterised by abduction limitation, ocular retraction, narrowing of the palpebral fissure in abduction, and ipsilateral medial rectus restriction on forced duction test. NF2 is also an uncommon disease which is characterised by peripheral and central nervous system tumours. Abducens nerve schwannomas are also uncommon and presents usually as diplopia. A short review of these diseases is given. This is the first case of pseudo-Duane secondary to abducens nerve schwannoma, to our knowledge.

The presence of anomalous extraocular bands in Duane retraction syndrome.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Bilateral augmented superior rectus transposition with medial rectus recession for bilateral esotropic Duane retraction syndrome.

Superior rectus transposition with medial rectus recession is commonly performed for unilateral esotropic Duane syndrome. For bilateral esotropic Duane syndrome, bilateral medial rectus recession is the most frequently performed surgery and usually provides satisfactory alignment in primary position; however, there is limited improvement in abduction. We report the outcomes of bilateral augmented superior rectus transposition and medial rectus recession in 4 patients with bilateral esotropic Duane syndrome. Postoperatively, abduction was improved in all patients; 3 were orthotropic in the primary position, and 1 had residual esotropia.

Variant types of Duane retraction syndrome: synergistic divergences and convergences.

PURPOSE: To present the clinical features of 4 patients with Duane retraction syndrome characterized by synergistic divergence or convergence, abnormal vertical movements, and accessory fibrotic bands. METHODS: The medical records of 4 patients were reviewed retrospectively for the following clinical manifestations: visual acuity, refraction, ocular alignments, ocular motility, head position, magnetic resonance imaging, surgical techniques, and outcomes. RESULTS: All 4 cases were diagnosed as variants of Duane retraction syndrome. Two cases (cases 1 and 2) had synergistic divergence with unilateral adduction deficit, and 2 (cases 3 and 4) had synergistic convergence with bilateral abduction deficit. Case 2 manifested abnormal vertical movements of the right eye, which goes down with adduction of the left eye and goes up oppositely with abduction of left eye. Accessory fibrotic bands were detected beside the medial rectus muscle of both eyes in case 3. Synergistic convergence in case 4 occurred only after the first strabismus surgery. Weakening of the misinnervated horizontal rectus muscle improved ocular alignment and head position in cases 1, 3, and 4. CONCLUSIONS: Synergistic divergence and convergence are extremely rare and may present with a great diversity of clinical features. A good outcome is very difficult to achieve; however, weakening of the misinnervated horizontal rectus muscle was therapeutic in these patients.

Contralateral lateral rectus muscle recession in a patient with unilateral exotropic Duane retraction syndrome type II: A case report.

A fixation preference for the affected eye is uncommon in patients with unilateral Duane retraction syndrome (DRS), and surgery on the fellow eye is rarely advocated. We are presenting a case report of a 9-year-old boy with unilateral DRS type II in the left eye who received lateral rectus muscle recession in his right amblyopic eye. The patient was orthophoric and his face turn was gone 6 months postoperatively. Surgery on the fellow amblyopic eye is a good choice for unilateral DRS where the affected eye dominants the fixation, and the satisfactory outcome suggests that alignment in the primary position can correct the face turn effectively despite the muscle duction deficit in the affected eye and further extend the binocular single visual field.