Orbital Imaging in Strabismus

Neuro-Ophthalmological Manifestations of Craniosynostosis: Current Perspectives

Craniosynostosis, a premature fusion of cranial sutures that can be isolated or syndromic, is a congenital defect with a broad, multisystem clinical spectrum. The visual pathway is prone to derangements in patients with craniosynostosis, particularly in syndromic cases, and there is a risk for permanent vision loss when ocular disease complications are not identified and properly treated early in life. Extensive advancements have been made in our understanding of the etiologies underlying vision loss in craniosynostosis over the last 20 years. Children with craniosynostosis are susceptible to interruptions in visual input arising from strabismus, refractive errors, and corneal damage; any of these aberrations can result in understimulation of the visual cortex during childhood neurodevelopment and permanent amblyopia. Elevated intracranial pressure resulting from abnormal cranial shape or volume can lead to papilledema and, ultimately, optic atrophy and vision loss. A pediatric ophthalmologist is a crucial component of the multidisciplinary care team that should be involved in the care of craniosynostosis patients and consistent ophthalmologic follow-up can help minimize the risk to vision posed by such entities as papilledema and amblyopia. This article aims to review the current understanding of neuro-ophthalmological manifestations in craniosynostosis and explore diagnostic and management considerations for the ophthalmologist taking care of these patients.

Extraocular muscle positions in anterior plagiocephaly: V-pattern strabismus explained using geometric mophometrics

INTRODUCTION

Ophthalmological involvement in anterior plagiocephaly (AP) due to unicoronal synostosis (UCS) raises management challenges. Two abnormalities of the extraocular muscles (EOM) are commonly reported in UCS without objective quantification: (1) excyclorotation of the eye and (2) malposition of the trochlea of the superior oblique muscle. Here we aimed to assess the positions of the EOM in AP, using geometric morphometrics based on MRI data.

MATERIALS AND METHODS

Patient files were listed using Dr WareHouse, a dedicated big data search engine. We included all patients with AP managed between 2013 and 2018, with an available digital preoperative MRI. MRIs from age-matched controls without craniofacial conditions were also included. We defined 13 orbital and skull base landmarks in order to model the 3D position of the EOM. Cephalometric analyses and geometric morphometrics with Procrustes superimposition and principal component analysis were used with the aim of defining specific EOM anomalies in UCS.

RESULTS

We included 15 preoperative and 7 postoperative MRIs from patients with UCS and 24 MRIs from age-matched controls. Cephalometric analyses, Procrustes superimposition and distance computations showed a significant shape difference for the position of the trochlea of the superior oblique muscle and an excyclorotation of the EOM.

CONCLUSIONS

Our results confirm that UCS-associated anomalies of the superior oblique muscle function are associated with malposition of its trochlea in the roof of the orbit. This clinical anomaly supports the importance of MRI imaging in the surgical management of strabismus in patients with UCS.

Ophthalmological management in craniosynostosis

INTRODUCTION

In published series, a large proportion of patients with craniosynostosis show impaired vision.

MATERIALS AND METHODS

A literature review was performed, using the PubMed and Google Scholar databases, to identify original and review articles on the consequences of craniosynostosis on the eyes and visual pathways, and on the ophthalmological management of craniosynostosis.

RESULTS AND DISCUSSION

Many ophthalmic, potentially sight-threatening, complications, can occur in patients with craniosynostosis, especially when syndromic. Optic neuropathy, mostly resulting from the papilledema-optic atrophy sequence, secondary to raised intracranial pressure (ICP), should be diagnosed early, in order to promptly lower the ICP. Cyclovertical and horizontal strabismus and refractive errors are frequent in unicoronal synostosis (anterior plagiocephaly) and syndromic craniosynostosis. Exorbitism, encountered in some cases of syndromic craniofacial synostosis, leads to exposure keratopathy, which requires aggressive management to avoid severe irremediable corneal complications. Amblyopia can result from optic neuropathy, corneal opacities, strabismus, or refractive errors. If undiagnosed and untreated at a young age, it results in permanent visual impairment.

CONCLUSION

Children with craniosynostosis require a multidisciplinary care network including a pediatric ophthalmologist. Systematic ophthalmological follow-up enables papilledema to be diagnosed and amblyopia to be diagnosed and treated, in order to avoid visual impairment.