Duane retraction syndrome: causes, effects and management strategies

Refractive features and amblyopia in Duane's Retraction Syndrome: A review of the 582 patients

PURPOSE

To report the visual and refractive characteristics and the prevalence of amblyopia in patients with different types of Duane's Retraction Syndrome (DRS).

METHOD

This retrospective study was performed on hospital records of 582 DRS patients at Farabi Hospital, Iran, from 2012 to March 2022.

RESULTS

The mean age of patients was 19.4 ± 11.9 (range, 3-70) years [335 (57.6 %) females and 247 (42.4 %) males (P < .001)]. DRS type I, II, III, and IV were presented in 347 (59.6 %), 148 (25.4 %), 82 (14.1 %), and 5 (0.9 %) patients, respectively. There were 530 (91.1 %) patients with unilateral and 52 (8.9 %) with bilateral involvement. In the unilateral patients, the DRS eyes' corrected distance visual acuity (CDVA) and astigmatism were significantly worse than the Non-DRS Eyes (P < .001). The mean amount of all refractive and visual parameters in bilateral patients' right or left eyes was significantly lower than in unilateral patients' non-DRS eyes (all P < .05). Anisometropia was observed in 75(12.9 %) of the patients. Amblyopia was observed in 18.5 % (98 patients) and 36.5 % (19 patients) of unilateral and bilateral DRS patients, respectively (P < .001). In unilateral patients, amblyopia was found in 57 (16.4 %) patients with Type I, 22 (14.9 %) patients with Type II, 16 (19.5 %) patients with Type III, and 3 (60 %) patients with Type IV. Forty-four (37.6 %) of patients with amblyopia had anisometropia.

CONCLUSION

This large-scale study indicates that DRS types differ in terms of refractive error, visual acuity, and the prevalence of amblyopia and anisometropia. Clinicians should be aware of the clinical features associated with different types of DRS.

Two cases of Duane retraction syndrome with abnormal orbital structures

Duane retraction syndrome (DRS) is a rare congenital nonprogressive restrictive strabismus. The absence/hypoplasia of the abducens nerve and the aberrant innervation of the lateral rectus muscle by the oculomotor nerve have been hypothesized as causes of DRS, although the phenomenon of globe retraction can also occur in the setting of mechanical factors, such as congenital abnormal orbital structures or orbital trauma. We present the cases of 2 DRS patients with absent abducens nerve and abnormal muscular bands connecting the superior rectus and inferior rectus muscles on the temporal side of the optic nerve.

Cat eye syndrome: Clinical, cytogenetics and familial findings in a large cohort of 43 patients highlighting the importance of congenital heart disease and inherited cases

Cat Eye Syndrome (CES) is a rare genetic disease caused by the presence of a small supernumerary marker chromosome derived from chromosome 22, which results in a partial tetrasomy of 22p-22q11.21. CES is classically defined by association of iris coloboma, anal atresia, and preauricular tags or pits, with high clinical and genetic heterogeneity. We conducted an international retrospective study of patients carrying genomic gain in the 22q11.21 chromosomal region upstream from LCR22-A identified using FISH, MLPA, and/or array-CGH. We report a cohort of 43 CES cases. We highlight that the clinical triad represents no more than 50% of cases. However, only 16% of CES patients presented with the three signs of the triad and 9% not present any of these three signs. We also highlight the importance of other impairments: cardiac anomalies are one of the major signs of CES (51% of cases), and high frequency of intellectual disability (47%). Ocular motility defects (45%), abdominal malformations (44%), ophthalmologic malformations (35%), and genitourinary tract defects (32%) are other frequent clinical features. We observed that sSMC is the most frequent chromosomal anomaly (91%) and we highlight the high prevalence of mosaic cases (40%) and the unexpectedly high prevalence of parental transmission of sSMC (23%). Most often, the transmitting parent has mild or absent features and carries the mosaic marker at a very low rate (<10%). These data allow us to better delineate the clinical phenotype associated with CES, which must be taken into account in the cytogenetic testing for this syndrome. These findings draw attention to the need for genetic counseling and the risk of recurrence.

Understanding Visual Disorders through Correlation of Clinical and Radiologic Findings

Patients presenting with visual disturbances often require a neuroimaging approach. The spectrum of visual disturbances includes three main categories: vision impairment, ocular motility dysfunction, and abnormal pupillary response. Decreased vision is usually due to an eye abnormality. However, it can also be related to other disorders affecting the visual pathway, from the retina to the occipital lobe. Ocular motility dysfunction may follow disorders of the cranial nerves responsible for eye movements (ie, oculomotor, trochlear, and abducens nerves); may be due to any abnormality that directly affects the extraocular muscles, such as tumor or inflammation; or may result from any orbital disease that can alter the anatomy or function of these muscles, leading to diplopia and strabismus. Given that pupillary response depends on the normal function of the sympathetic and parasympathetic pathways, an abnormality affecting these neuronal systems manifests, respectively, as pupillary miosis or mydriasis, with other related symptoms. In some cases, neuroimaging studies must complement the clinical ophthalmologic examination to better assess the anatomic and pathologic conditions that could explain the symptoms. US has a major role in the assessment of diseases of the eye and anterior orbit. CT is usually the first-line imaging modality because of its attainability, especially in trauma settings. MRI offers further information for inflammatory and tumoral cases. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Iatrogenic Pseudo-Duane Retraction Syndrome Following Orbitozygomatic Craniotomy

Restrictive strabismus is a known complication of orbitozygomatic craniotomy. However, a pseudo-Duane syndrome has not been described following this procedure. The authors describe a 58-year-old woman who after craniotomy developed incomitant left exotropia with an adduction deficit; the globe retracted and palpebral fissure narrowed with attempted ocular adduction. [J Pediatr Ophthalmol Strabismus. 2024;61(1):e7-e10.].

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.

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.

Bilateral Lateral Rectus Recession in Duane Retraction Syndrome Type II: A Case Report

A two year presented to the clinic with abnormal head posture and right-sided face turn since birth. On examination, he showed a large right face turn of 40° while concentrating on a near target. His ocular motility assessment showed a -4 limitation of adduction in the left eye with 40 prism diopters (PD) exotropia and grade 1 globe retraction of the left eye. He was diagnosed with type II Duane retraction syndrome (DRS) in the left eye and planned for lateral rectus recession of both eyes. Postoperatively, the patient was orthotropic at distance and near in primary gaze with resolved face turn and improvement of limitation of adduction to -2, but some limitation of abduction -1 in the left eye was observed. Herein, we discuss the clinical features, etiologies, tailored evaluation, and management for type II DRS patient.

Duane Retraction Syndrome: The Role of Botulinum Toxin A Injection in Adults and Its Impact on Quality of Life in an Indian Population

PURPOSE

To evaluate the role of botulinum toxin A in the treatment of adults with Duane retraction syndrome and its impact on quality of life.

METHODS

A total of 25 adults with unilateral Duane retraction syndrome were selected for this interventional case series. Botulinum toxin was injected in the appropriate horizontal recti. The parameters assessed were ocular deviation (▵), overshoots, and abnormal head posture. Patients were followed up at 1 day, 10 days, and 3 months after the injection. The outcome was categorized on the basis of deviation/abnormal head posture/overshoots as: (1) significant improvement (< 8 prism diopters [PD]/< 5 degrees/≤ grade 1); (2) partial improvement (8 to 20 PD/5 to 15 degrees/≤ grade 2); and (3) no improvement (> 20 PD/> 15 degrees/≥ grade 3). Patients with partial/significant improvement were considered to have a favorable outcome. The impact on quality of life was assessed using the Adult Strabismus-20 Questionnaire scores 10 days after injection.

RESULTS

There was a significant reduction in ocular deviation in esotropic and exotropic Duane retraction syndrome at 10 days (P = .001) and 3 months (P = .04) after botulinum toxin injection. The abnormal head posture improved from 11.58 ± 7.43 to 7.86 ± 6.25 degrees at 10 days. Botulinum toxin had a positive impact on the Adult Strabismus-20 Questionnaire scores, which significantly improved (P < .05) at 10 days. A favorable outcome was noted in 21 patients at 10 days but only 4 patients at 3 months. Three patients developed ptosis and 1 patient with orthotropic Duane retraction syndrome developed transient exotropia.

CONCLUSIONS

In adults with Duane retraction syndrome, botulinum toxin can have a useful diagnostic role by providing insight to patients and setting realistic expectations. It can identify patients likely to benefit from further treatment and also has a positive impact on quality of life. [J Pediatr Ophthalmol Strabismus. 2023;60(1):46-51.].

Duane Retraction Syndrome With Mechanical and Innervational Upshoot and Secondary Superior Rectus Contracture: A Surgical Challenge

Duane retraction syndrome (DRS) with mechanical and innervational upshoot poses a surgical challenge. We discuss a case of DRS with mechanical and innervational upshoot and its surgical management. An 11-year-old boy presented with left eye upward deviation since birth. This deviation was worst on the right gaze. His best corrected visual acuity was 6/6 OD and 6/60 OS. Refraction showed low hyperopia with low astigmatism in both eyes. Stereoacuity was absent and there was suppression on the Worth 4 dot test in the left eye. The left eye had large hypertropia of 50 prism diopter in primary gaze. Extraocular movements showed severe upshoot and narrowing of palpebral fissures on adduction and limited abduction (-2). The patient underwent Y-splitting of the left lateral rectus (LR) muscle of 10 mm, LR recession of 4 mm, and left eye superior rectus recession of 12 mm. A marked reduction in hypertropia in primary gaze was observed on day one and at two months postoperatively with residual upshoot on adduction. His left eye deviation remained stable after six months postoperatively.

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.

Clinical profile and magnetic resonance imaging characteristics of Duane retraction syndrome

PURPOSE

To describe the clinical profile and magnetic resonance imaging findings of the brain in Duane retraction syndrome (DRS) and determine whether there is an association between clinical presentation and magnetic resonance imaging (MRI) brain characteristics.

MATERIALS AND METHODS

This was a cross-sectional study done at a tertiary care center in South India. We recruited and analyzed the clinical characteristics of 54 patients with DRS. MRI of the brain with fast imaging employing steady-state acquisition (FIESTA) was performed in 41 cases, and the cisternal segment of the sixth nerve was studied. Statistical analysis was done to determine any association between the radiological and clinical features.

RESULTS

Type 1 DRS was predominant, followed by Type 3 DRS and Type 2 DRS. 9.3% of cases were bilateral and 11.1% were familial. Orthotropia was most common, followed by esotropia and exotropia. The MRI brain showed the absence of the cisternal part of the sixth nerve on the affected side in 82% of Type 1 and 75% of Type 3 unilateral DRS. Both the abducens nerves were visualized in 19.5% of the patients with unilateral DRS. There was no statistically significant association between MRI brain findings and the clinical features.

CONCLUSIONS

MRI brain with FIESTA shows absent or hypoplastic sixth nerve in most cases of Type 1 and Type 3 DRS. However, around 20% of DRS cases may show the presence of the cisternal part of the sixth nerve. Hence, clinicians must be cautious when ruling out DRS on the basis of MRI brain findings. Although aplasia of the sixth nerve is the most frequent MRI finding, it may not be the sole etiologic factor.

[Improvement of surgical treatment of Duane syndrome in children]

PURPOSE

To analyze the use of bifurcation of the lateral rectus muscle (LRM) in the surgical treatment of Duane syndrome (DS) in children.

MATERIAL AND METHODS

The analysis of surgical treatment involved 12 children with paralytic strabismus at the age of 8 to 17. The following research methods were conducted for all patients: the study of eye motility in different directions of gaze, the study of eyes position and the degree of deviation in different positions of gaze, the Bielschowsky test, the Park's three-step test, determination of the nature of torticollis, the forcing test - intraoperative forceps test, multislice computed tomography (MSCT) of the head and orbit, ultrasonography of the oculomotor muscles. All study children underwent bifurcation (Y-cleavage procedure) of LRM with recession in exo-DS in 17% of cases, without recession in eso-DS - 83% of cases, respectively.

RESULTS

In all operated patients with Duane syndrome, the direction of LRM was compensated (downshoot and upshoot were eliminated). In a direct gaze, the correct position was achieved in 10 (83%) cases, in 2 (17%) the residual angle of up to 10 PD remained, and torticollis was eliminated in 9 (75%) patients.

CONCLUSION

The method of LRM bifurcation - the procedure of dividing the muscle into two portions and changing its primary localization, accompanied by abnormalities (presence of deviation, retraction, anomalous vertical movements, limited ocular motility, etc.), - helps compensate for them, and provides cosmetic as well as functional improvement.

Transient congenital Horner syndrome and multiple peripheral nerve injury: a scarcely reported combination in birth trauma

Objectives

To describe an infrequent association of multiple injuries in relation to perinatal trauma and the challenge of clinical examination for proper diagnosis.

Case presentation

A male newborn was born at 41 weeks gestational age to a multipara diabetic mother, by forceps. Apgar 8/9. Upon admission, he exhibited axial hypotonia, right brachial paresis, a large left parietal cephalohematoma, but no skull fractures or orbital injuries. He also showed ocular misalignment with marked esotropia of the right eye, ptosis and mild anisocoria, suggesting right Horner syndrome, and left facial palsy. During the oculo-cephalic reflex examination he exhibited a normal adduction and impaired abduction of the right eye. The cranial MRI showed an extensive left parietal cephalohematoma, with internal foci of recent bleeding, and supra and infratentorial laminar subdural hematomas. No lesions were evidenced in the cavernous sinuses. The recovery of extra and intraocular motility at one month of life in our patient highlighted the transitory nature of the lesions and was reassuring for the parents.

Conclusions

This case highlights the importance of a detailed clinical examination in the initial evaluation of a newborn at neurological risk after birth trauma. The association of sixth cranial nerve palsy, Horner syndrome, facial palsy, and brachial plexus injury have been scarcely referred in this context and, if not adequately interpreted, might suggest erroneous diagnoses with very different prognoses.

Duane-minus (Duane sine retraction and Duane sine limitation): possible incomplete forms of Duane retraction syndrome

PURPOSE

To report ocular motility patterns that mimic, but do not fulfil the full clinical picture of Duane retraction syndrome (DRS) and to describe their clinical features and surgical management.

METHODS

This is a retrospective case series study conducted on patients with DRS, mimicking non-comitant exotropia or esotropia and a face turn. Patients were included only if they lacked either globe retraction on adduction (sine retraction) or limitation of adduction or abduction on ductions (sine limitation not >0.5). Any overshoots or pattern strabismus was recorded. The ocular motility and alignment, details of surgery and their surgical outcomes were analysed.

RESULTS

Twenty-one patients were identified; 13 in the sine retraction and 8 in the sine limitation group. All patients presented with a compensatory face turn. Overshoots were present in 10 (77%) and 7 patients (88%) in the sine retraction and sine limitation groups, respectively. Forced duction test showed tightness of the ipsilateral medial and the ipsilateral lateral rectus muscle in esotropic (n = 3) and exotropic patients (n = 18), respectively. Orthotropia was achieved in 82% of patients following ipsilateral medial or lateral rectus muscle recession.

CONCLUSIONS

There is a subset of patients who present with motility pattern similar to DRS but lack its complete diagnostic criteria. The presence of a face turn, overshoots on adduction or an ipsilateral tightness of the affected muscle should make one consider DRS sine retraction/sine limitation. The patients in our study responded well to lines of management similar to those of DRS.

Solitary median maxillary central incisor with congenital strabismus and autoimmune thyroiditis in a young child

Single median maxillary central incisor (SMMCI) syndrome is rare. It is commonly associated with other midline defects. About 50% of children with SMMCI have short stature, associated with isolated growth hormone deficiency or panhypopituitarism.A 6-year-old girl presented to us with worsening convergent squint, slowing linear growth and a suspected pituitary macroadenoma on neuroimaging. The key findings on examination included a disproportionate short stature, SMMCI, congenital abduction defect and pseudohypertrophy of calf muscles with myopathy. The evaluation showed autoimmune thyroiditis with pituitary hyperplasia. Bone age corresponded to 3 years.Three months after initiation of thyroxine, her myopathy resolved, and the hormone profile and neuroimaging were normal. Autoimmune thyroiditis in association with SMMCI is not reported previously. This case study emphasises the importance of growth monitoring and the exclusion of common treatable conditions.

Neonatal diagnosis of Marcus Gunn jaw-winking syndrome

This report highlights the importance for neonatologists/pediatricians of considering Marcus Gunn jaw-winking syndrome among differential diagnoses of ptosis. A detailed clinical assessment is crucial to promptly recognize and appropriately manage it.

A rare association of type 2 Duanes retraction syndrome with arthrogryposis multiplex congenita

A 10-year-old boy presented with complaints of abnormal eye movements and face turn since early There was a limitation of adduction in LE with narrowing of palpebral fissure and downshoot characteristic of type 2 Duane Syndrome. He was a known case of Arthrogryposis multiplex congenita (AMC) and had undergone multiple orthopedic surgeries. The literature on Duane Retraction Syndrome (DRS) in AMC is limited. Here, we report in brief the association of DRS type 2 in AMC.

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.

Case Report: Unilateral Sixth Cranial Nerve Palsy Associated With COVID-19 in a 2-year-old Child

Children have been described to show neurological symptoms in acute coronavirus disease 2019 (COVID-19) and multisystemic inflammatory syndrome in children (MIS-C). We present a 2-year-old boy's clinical course of unilateral acute sixth nerve palsy in the context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Onset of the palsy in the otherwise healthy boy occurred seven days after symptoms attributed to acute infection had subsided respectively 3 weeks after onset of respiratory symptoms. SARS-CoV-2 specific IgG was detected in serum as well as in cerebrospinal fluid. The patient showed a prolonged but self-limiting course with a full recovery after three and a half months. This case illustrates in a detailed chronological sequence that sixth cranial nerve involvement may occur as post-infectious, self-limiting complication of pediatric SARS-CoV-2-infection thus expanding the neurological spectrum of symptoms for children with COVID-19. Clinicians should be aware of the possibility of post-infectious sixth nerve palsy related to SARS-CoV-2-infection particularly in view of recent respiratory tract infection or confirmed cases of SARS-CoV-2-infection amongst the patient's close contacts.

Imaging of congenital cranial dysinnervation disorders: What radiologist wants to know?

We aim to review the imaging features of congenital cranial dysinnervation disorders. Characteristic imaging findings can define subtypes of these disorders through assessment of cranial nerves, extraocular muscles, orbital, and brain abnormalities. Duane retraction syndrome shows absent or hypoplasic 6th cranial nerve and preserved extraocular muscles (EOM). Mobius syndrome shows absent 7th and 6th cranial nerves, absence of facial colliculus, flattening of the dorsal aspect of the pons, hypoplasia of the pons and medulla, and flattening of the 4th ventricular floor. Congenital fibrosis of the extraocular muscles reveals unilateral or bilateral hypoplasia or aplasia of the 3rd cranial nerve, atrophy of superior rectus and levator palpebrae superioris muscles, and atrophy of the brainstem and cerebellar hemispheres. Horizontal gaze palsy and progressive scoliosis show characteristic split pons sign, butterfly medulla, absent facial colliculi, and spinal scoliosis. HOXA1 Mutations show a bilateral absence of 6th cranial nerves with the underdeveloped inner ear. Pontine Cap Tegmental Dysplasia shows ventral pontine hypoplasia, dorsal tegmental projection into the 4th ventricle, and variable cranial nerve deficits.

Unilateral medial rectus muscle recession combined lateral rectus muscle marginal myotomy for the treatment of Duane's retraction syndrome: A promising surgical procedure

Background:

Duane's retraction syndrome is a congenital eye movement anomaly with narrowing of the palpebral fissure and globe retraction on attempted adduction. There are several surgical approaches to treat the narrowing of the palpebral fissure. The purpose of the present study was to evaluate the efficacy of unilateral medial rectus recession (MRR) muscle combined lateral rectus (LR) muscle marginal myotomy (MM) with unilateral MRR alone in the management of narrowing of the palpebral fissure of patients with Type 1 Duane's retraction syndrome (DRS).

Materials and Methods:

Twenty-eight patients with unilateral DRS Type 1 were randomly divided into two groups (14 eyes of 14 patients in each group). Age ≥5 years with DRS Type 1 with <20 prism diopters in primary position who were candidates for surgery were consecutively enrolled in this randomized controlled trial. Patients were divided into treatment groups to receive unilateral MR recession with simultaneous MM group or with unilateral MR recession alone. The amount of deviation in primary position, abnormal head position, palpebral fissure width (PFW), and up/down shoot was evaluated before and 3 months after the surgery. This study was registered at the Iranian Registry of Clinical Trials under the registration code IRCT20131229015975N3.

Results:

PFW increased within MRR/MM group at the end of the study (8.86 ± 1.51) compared with the baseline (7.79 ± 1.48) (P < 0.001). In contrast, in the MRR/MM group, PFW did not increase statistically significantly within the MRR group at the end of the study (8.14 ± 1.35) compared with the baseline (8.07 ± 1.38) (P = 0.67). Mean ± standard deviation of PFW (mm) in MRR/MM group after surgery (8.86 ± 1.51) was statistically significantly higher than that in the MRR group (8.14 ± 1.35), (P = 0.002).

Conclusion:

The results of our study demonstrate PFW significantly increased after unilateral MRR muscle combined LR muscle MM.

Morphometry of the Oculomotor Nerve in Duane’s Retraction Syndrome

Objective: To investigate the morphometric characteristics of the oculomotor nerve and its association with horizontal rectus muscle volume in patients with Duane’s retraction syndrome (DRS) according to the presence of the abducens nerve. Methods: Fifty patients diagnosed with unilateral DRS were divided into two groups according to high-resolution magnetic resonance imaging (MRI) findings; DRS without an abducens nerve on the affected side (absent group, n = 41), and DRS with symmetric abducens nerves on both sides (present group, n = 9). Oculomotor nerve diameter was measured on high-resolution MRI in the middle of the cisternal space. The medial rectus muscle (MR) and lateral rectus muscle (LR) volumes were measured on T2-weighted coronal MRI of the orbit. Associations of oculomotor nerve diameter and horizontal rectus muscle volumes were performed according to the presence and absence of the abducens nerve. Results: Oculomotor nerve diameter on the affected side was thicker than that of the non-affected side in the absent group (p < 0.001), but not in the present group (p = 0.623). In the absent group, there was a positive correlation between oculomotor nerve diameter and MR volume (r = 0.779, p < 0.001), as well as the LR volume (r = 668, p = 0.023) of the affected eye. Conclusions: In DRS patients with an absent abducens nerve, the oculomotor nerve diameter was thicker in the affected eye compared to the non-affected eye. Oculomotor nerve diameter was associated with MR and LR volumes in the absent group. This study provides structural correlates of aberrant innervation of the oculomotor nerve in DRS patients.

Myopathic Blepharoptoses: A New Classification System

PURPOSE

Myopathic blepharoptoses (ptoses) is a complex group of disorders. To date, no formal categorization scheme has been developed based on associated ocular and systemic findings, genetic fingerprint, treatment, and prognosis for each ptosis in this group. We report a new classification scheme for myopathic ptoses.

METHODS

Literature review and classification development.

RESULTS

A new classification scheme of myopathic ptoses includes isolated static myopathic ptosis (congenital ptosis), static myopathic ptosis associated with aberrant innervation and those associated with periocular abnormalities, and progressive myopathic ptoses that affect the levator muscle and other muscle groups in childhood and adulthood.

CONCLUSIONS

Making the distinction of myopathic ptosis type early will maximize patient outcomes by optimizing surgical and systemic management and facilitating the recruitment of subspecialists to care for patients with these challenging conditions.The authors present a comprehensive and effective myopathic ptosis classification scheme to optimize surgical management and facilitate subspecialty care.

Duane's Retraction Syndrome in a Cohort of South African Children: A 20-Year Clinic-Based Review

PURPOSE

To describe the clinical features of Duane's retraction syndrome in a cohort of South African children and to analyze the differences between ethnic groups.

METHODS

A retrospective case series of 120 patients seen between 1997 and 2017 at a tertiary referral center in Cape Town, South Africa.

RESULTS

Type 2 Duane's retraction syndrome was most common in black children (54%), whereas type 1 was predominant in mixed race (68%) and white (94%) children. In this cohort, 63% of black children with Duane's retraction syndrome were boys, whereas 69% of white children and 59% of mixed race children were girls. Left eye involvement was the most common in all ethnic groups (44%), followed by right eye (41%) and bilateral (14%) involvement. The average age at presentation was 34.2 months (range: 1 to 144 months). Strabismus in primary position was present in 57 patients (46%), of whom 39% had esotropia and 61% had exotropia. A deviation in the primary position was more common in black (71%) children than in mixed race (39%) or white (41%) children. Ametropia was found in 94 patients (79%), amblyopia was present in 15 patients (13%), and 41 patients (34%) underwent surgery.

CONCLUSIONS

This is the first study to provide robust data on the profile of pediatric Duane's retraction syndrome in the three main ethnic groups in South Africa, and it showed clear ethnic differences. Among black children, boys are affected more often, the proportion with type 2 Duane's retraction syndrome is more frequent, and surgery is required more often. Among white and mixed race children, girls are affected more often and type 1 Duane's retraction syndrome is predominant. [J Pediatr Ophthalmol Strabismus. 2019;56(4):248-253.].

Management of Duane retraction syndrome: A simplified approach

Duane retraction (or co-contraction) syndrome is a congenital restrictive strabismus which can occur either as an isolated entity or in conjunction with other congenital anomalies and is now listed as a congenital cranial dysinnervation disorder. It is characterized by co-contraction of horizontal recti on attempted adduction causing globe retraction along with variable amounts of upshoots or downshoots. It may have limited abduction or adduction or both and present as esotropic, exotropic, or orthotropic Duane. The diagnosis of this disease is usually clinical. However, recent research has provided a greater insight into the genetic basis of this disease paving a way for a greater role of genetics in the diagnosis and management. This disease can have a varied presentation and hence the treatment plan should be tailor-made for every patient. The indications for surgery are abnormal head posture, deviations in the primary position, retraction and narrowing of palpebral aperture and up- or downshoots during adduction, and sometimes also to improve abduction. The arrival of newer surgical techniques of periosteal fixation (PF) of lateral rectus (LR), partial vertical rectus transposition, or superior or inferior rectus transposition in addition to LR recession with Y-split has vastly improved the management outcomes, providing not only primary position orthophoria but also increased binocular visual fields as well.

Altered brain activity in patients with strabismus and amblyopia detected by analysis of regional homogeneity: A resting‑state functional magnetic resonance imaging study

Previous studies have demonstrated that strabismus or amblyopia can result in marked brain function and anatomical alterations. However, differences in spontaneous brain activity in strabismus and amblyopia (SA) patients as compared with control individuals remain unclear. The present study aimed to analyze the potential brain activity changes in SA patients and their association with behavioral performance. In total, 16 patients with SA (10 women and 6 men) and 16 healthy controls (HCs; 6 men and 10 women) with matched age and sex were recruited. All subjects were examined with resting-state functional magnetic resonance imaging (rs-fMRI), and changes in the spontaneous brain activity of SA patients were evaluated by the regional homogeneity (ReHo) method. The diagnostic ability of the ReHo method was assessed using receiver operating characteristic (ROC) curve analysis. In addition, the association between the mean ReHo value in different brain regions and the behavioral performance was explored by correlation analysis. It was observed that the ReHo value was significantly increased in SA patients compared with HCs in the following brain regions: left lingual gyrus, right middle occipital gyrus/precuneus, bilateral anterior cingulate, left middle occipital gyrus and bilateral precentral gyrus. By contrast, the ReHo value of the left inferior frontal gyrus was significantly lower than that in HCs. ROC curve analysis indicated that the ReHo method has certain credibility for the diagnosis of SA patients. In addition, no similar changes were detected in other brain regions. These results revealed abnormal spontaneous brain activity in certain parts of the brain in adult patients with SA, which suggests the involvement of the neuropathological or compensatory mechanism in these patients, and may be beneficial for clinical treatment.

Neuroradiological and clinical features in ophthalmoplegia

PURPOSE

Especially in acute onset of ophthalmoplegia, efficient neuroradiological evaluation is necessary to assist differential diagnosis, clinical course, and treatment options.

METHODS

Different manifestations of ophthalmoplegia are explained and illustrated by characteristic neuroradiological and clinical findings.

RESULTS

To present those ophthalmoplegic disorders in a clear manner, this review refers to different neuroanatomical structures and compartments. From neuroophthalmological point of view, diseases going ahead with ophthalmoplegia can be divided into (1) efferent infranuclear/peripheral disturbances involving oculomotor cranial nerves, (2) conjugate gaze abnormalities due to internuclear or supranuclear lesions, and (3) diseases of the extraocular eye muscles or their impairment due to intraorbital pathologies.

CONCLUSION

The knowledge of the relationship between neurological findings in ophthalmoplegia and involved neuroanatomical structures is crucial, and neuroradiology can be focused on circumscribed anatomical regions, using optimized investigation protocols.

Duane Retraction Syndrome: Clinical Features and a Case Group-Specific Surgical Approach

PURPOSE

To describe the clinical features of patients with Duane retraction syndrome (DRS) and evaluate the outcomes of surgical approaches based on the characteristics of each patient.

METHODS

The records of 38 Caucasian subjects with DRS were retrospectively reviewed. The patients were classified as type I, II, or III based on the Huber Classification. Ten patients underwent unilateral medial rectus (MR) recession due to abnormal head posture (AHP) and/or esotropia. Four patients underwent Y-splitting and recession of the lateral rectus (LR) with MR recession due to AHP and/or esotropia, upshoot, and globe retraction.

RESULTS

There was a preponderance of unilaterality, female gender, left eye, type I, orthotropia, upshoot, and low refractive error. All patients demonstrated globe retraction and fissure narrowing. AHP was only present in unilateral cases. Nine patients had amblyopia. More than half of the patients over 5 years of age had decreased stereopsis. MR recession decreased AHP to less than 8° in all patients. Y-splitting and recession of the LR eliminated upshoot in all four patients. One patient who underwent an 8-mm MR recession demonstrated -2 adduction limitation.

CONCLUSIONS

The DRS patients in our study demonstrated features that are consistent with previous reports in the literature. This study emphasizes the need to consider disease classification in the surgical management of DRS patients.

Neural crest and the patterning of vertebrate craniofacial muscles

Patterning of craniofacial muscles overtly begins with the activation of lineage-specific markers at precise, evolutionarily conserved locations within prechordal, lateral, and both unsegmented and somitic paraxial mesoderm populations. Although these initial programming events occur without influence of neural crest cells, the subsequent movements and differentiation stages of most head muscles are neural crest-dependent. Incorporating both descriptive and experimental studies, this review examines each stage of myogenesis up through the formation of attachments to their skeletal partners. We present the similarities among developing muscle groups, including comparisons with trunk myogenesis, but emphasize the morphogenetic processes that are unique to each group and sometimes subsets of muscles within a group. These groups include branchial (pharyngeal) arches, which encompass both those with clear homologues in all vertebrate classes and those unique to one, for example, mammalian facial muscles, and also extraocular, laryngeal, tongue, and neck muscles. The presence of several distinct processes underlying neural crest:myoblast/myocyte interactions and behaviors is not surprising, given the wide range of both quantitative and qualitative variations in craniofacial muscle organization achieved during vertebrate evolution.