From the Guidelines
Duane syndrome is a congenital eye movement disorder characterized by limited horizontal eye movement, with affected individuals unable to fully move their eye outward (abduction), inward (adduction), or both, and is often associated with other conditions in syndromes like Duane radial ray syndrome (DRRS) and Wildervanck syndrome.
Definition and Characteristics
Duane syndrome results from abnormal development of the sixth cranial nerve (abducens) and its nucleus, which normally controls the lateral rectus muscle responsible for outward eye movement. There are three types: Type 1 (limited abduction), Type 2 (limited adduction), and Type 3 (limited abduction and adduction) 1.
Related Syndromes
Other conditions that are associated with exotropia include Duane syndrome, congenital fibrosis syndrome, craniofacial abnormalities, and ocular myasthenia gravis 1. Some syndromes that have overlapping features with cardio-facio-cutaneous syndrome, which may be relevant in the differential diagnosis of Duane syndrome, include:
- NS with multiple lentigines (formerly LEOPARD syndrome)
- Baraitser-Winter syndrome
- NS with loose anagen hair These syndromes have distinct features, such as hypertelorism, ptosis, short stature, and cognitive delay, but may also present with similar characteristics, making diagnosis challenging 1.
Diagnosis and Management
Diagnosis of Duane syndrome involves a comprehensive ophthalmic examination, including assessment of extraocular muscle function, binocular alignment, and sensory testing 1. Treatment is primarily observational for mild cases, but may include glasses for refractive errors, patching for amblyopia, or strabismus surgery to improve eye alignment and reduce abnormal head positioning. Surgery doesn't restore normal eye movement but can improve cosmetic appearance and reduce compensatory head turns. Patients should be monitored regularly by an ophthalmologist, particularly children, to prevent amblyopia and ensure proper visual development. The condition is typically non-progressive and compatible with normal visual function when properly managed. Key considerations in the management of Duane syndrome include:
- Regular monitoring by an ophthalmologist
- Glasses for refractive errors
- Patching for amblyopia
- Strabismus surgery for severe cases
- Prevention of amblyopia and ensuring proper visual development in children.
From the Research
Definition and Characteristics of Duane Syndrome
- Duane syndrome is a congenital cranial dysinnervation disorder characterized by variable horizontal duction deficits, globe retraction, and narrowing of the palpebral aperture on attempted adduction 2, 3, 4.
- It is usually unilateral, with a female preponderance, and can be classified into different types based on the severity of the clinical findings 2, 4.
- The syndrome is caused by dysinnervation of the lateral rectus muscle due to aplastic or hypoplastic abducens nucleus, with a secondary aberrant supply to the lateral rectus by the medial rectus subnucleus of the oculomotor nerve 2, 3.
Related Syndromes and Classification
- Duane retraction syndrome (DRS) is another term used to describe this condition, characterized by impaired ocular motility, palpebral fissure narrowing, and globe retraction 3, 4.
- Huber classification is used to categorize DRS into three types, with type I being the most common form 4.
- Classification based on primary position deviation (esotropic, exotropic, or orthotropic) is also used to guide surgical management 4.
Clinical Presentation and Diagnosis
- Patients with Duane syndrome may present with limited abduction, limited adduction, or both, and may have associated globe retraction, upshoots, and downshoots 2, 3, 4.
- Diagnosis is usually clinical, and surgical management is individualized based on the severity of the clinical findings and the presence of associated anomalies 2, 5, 4.
Management and Treatment
- Surgical management of Duane syndrome aims to achieve alignment in the primary gaze, reduce globe retraction, upshoots, and downshoots, and correct abnormal head posture 2, 6.
- Recession of the lateral rectus muscle with Y-splitting is an effective procedure for treating significant upshoot and downshoot associated with globe retraction in Duane syndrome 6.
- Orthoptics, surgery, or monitoring may be used to manage the condition, depending on the severity of the clinical findings and the presence of associated anomalies 3, 5, 4.