Ophthalmological outcomes of unilateral coronal synostosis in young children

Craniosynostosis incidence with abnormalities of orbital axis on patients under 8 years old

Background

Craniosynostosis may result in malformations of the orbit, which can be observed in clinical presentations. Craniosynostosis impairs the normal growth of the skull, which typically occurs perpendicular to the fused suture. Craniosynostosis is classified into non-syndromic and syndromic, with an incidence of 1: 2000-2500 live births. It is commonly affects the sagittal suture (40-60%), followed by the coronal suture (20-30%), the metopic suture (<10%), and rarely the lambdoid suture. Computed tomography (CT) scan plays a crucial role in identifying the type of cranial abnormality and associated disruptions in the orbital axis (OX).

Methods

The research sample was craniosynostosis patients who were examined at the Radiology Department of Dr. Soetomo General Hospital at Surabaya, Indonesia for the period January 2017-March 2022, male or female aged <8 years and have never had head surgery. Evaluation of the position and axis of the extraocular muscles within the orbits is drawn on the coronal section. In this study, pediatric CT images were acquired at 100 kVp (CTDIvol 2.3 mGy; DLP 84.8 mGy*cm; scan time 6.1 s; helical pitch 0.297). The research was conducted using a case-control method. The case group consisted of patients with craniosynostosis, while the control group included patients without craniosynostosis, encompassing those with conditions such as meningoencephalitis. After the data source is obtained, then the case and control data are matched and then the Chi-square correlation test is carried out through Statistical Package for the Social Sciences.

Results

A significant correlation was found between the incidence of craniosynostosis and abnormalities of OX (P-value: 0.000; OR: 22.81; R: 0.635).

Conclusion

There is a significant correlation between the incidence of craniosynostosis that has two or more sutural fusions and abnormalities of OX. Strabismus associated with craniosynostosis is typically detected in patients at an older age. Hopefully, by analyzing the eye angle through CT scans while craniosynostosis is established, abnormalities of the orbital axis can be identified. So the progression of strabismus can be prevented.

Variations in orbital morphology, globe:orbit volume relation, and ophthalmological outcome in unicoronal synostosis

Nonsyndromic unicoronal synostosis is associated with variability of severity in orbital morphology and ophthalmological manifestations. The relation between the two is not fully understood, nor how surgical treatment with fronto-orbital advancement and remodelling (FOAR) changes the relation. The aim of this study was to elucidate associations between ophthalmological manifestations and variations in orbital morphology and globe:orbit volume ratios preoperatively and at long-term follow-up after surgery. Twelve children referred to Uppsala Craniofacial Center who underwent computed tomography and standardized ophthalmological examinations regarding strabismus, spherical equivalent, astigmatism, anisometropia, and subnormal vision preoperatively and at 3 years of age were included. Orbits and globes were segmented. Principal component analysis elucidated morphological variation, and symmetry between orbital pairs was measured as the Dice similarity coefficient and globe:orbit volume ratios were calculated. The defined orbital shape variations were correlated with strabismus, refractive error, and subnormal vision. Different shape variations were associated with strabismus pre- and postoperatively and ipsi- and contralateral astigmatism. Greater improvement in orbital symmetry after surgery was associated with improvement in astigmatic anisometropia and new onset strabismus at follow-up. A small globe:orbit volume ratio was associated with preoperative strabismus, while the opposite was seen at follow-up. Different mechanisms seem to cause strabismus pre- and postoperatively, and FOAR might not sufficiently correct orbital morphology.

Understanding the heterogenicity of unicoronal synostosis - A morphometric analysis of cases compared to controls

BACKGROUND

Preoperative severity of unicoronal synostosis varies greatly and involves the frontal bone, skull base and orbits. Degree of deformity affects long-term morphological and functional outcomes after surgery. The aim of this study was to describe the morphological heterogenicity and investigate its relation to patient-specific factors.

MATERIALS AND METHODS

In this retrospective cohort study, non-syndromic unicoronal synostosis patients treated between 2006 and 2022 at Necker Hospital, France or Uppsala University Hospital, Sweden, were included and matched to controls. Severity of skull base, orbital and posterior skull asymmetry, degree of anterior plagiocephaly and Harlequin deformity, lateralisation, head circumference, age, timing of metopic fusion and fusion of peri-pterionic sutures were investigated.

RESULTS

Ninety-five patients and ninety-three controls were included. Skull base asymmetry was linearly related to orbital asymmetry (p < 0.001), correlated with earlier CT scans (p = 0.004) and anterior (p < 0.001) and posterior (p = 0.03) plagiocephaly. Posterior plagiocephaly was more common in patients (31%) compared with controls (5%) (p < 0.001). A patent metopic suture above nine months of age was associated with severe Harlequin deformity (p = 0.04) and a lower head circumference when fused (p = 0.03). Fronto-sphenoidal suture fusion was associated with later CT scans (p < 0.001) and less skull base asymmetry (p = 0.002). Spheno-parietal fusion was correlated with decreased skull base asymmetry (p = 0.03). Right lateralisation was more common in females.

CONCLUSIONS

Heterogenicity of unicoronal synostosis seems to be predominantly explained by variability in skull base morphology. Peri-pterionic fusions might limit deformity.

Lacrimal Obstruction in Craniosynostosis: Anatomical and Genetic Risk Factors

PURPOSE

To investigate whether patients with craniosynostosis exhibit higher rates of nasolacrimal duct obstruction (NLDO) and to explore potential risk factors.

METHODS

Retrospective review including all craniosynostosis patients treated at both the Divisions of Ophthalmology and Plastic, Reconstructive, and Oral Surgery at The Children's Hospital of Philadelphia between 2009 and 2020 was conducted. Synostosis characteristics, lacrimal disorders, and genetic data were collected. Main outcome measures were the rate of NLDO and associations with anatomical and syndromic/genetic risk factors.

RESULTS

The total of 767 participants had a mean age of 2.8 ± 3.8 years, 465 (60.6%) were males, 485 (63.2%) had no syndromic association; 631 (82.3%) had one major suture involved, 128 (17%) had involvement of 2 to 4 major sutures, and 429 (55.9%) underwent craniofacial surgery. Forty-eight (6.2%) patients had NLDO, which more prevalent in the genetic/syndromic group (11.0% vs. 3.5%, respectively, p < 0.001), with the highest prevalence observed in patients with Apert syndrome (n = 4, 30.8%). The genetic variants most associated with NLDO were EFNB1 (n = 1, 100%) and FGFR2 (n = 6, 19.4%). There was no association between NLDO and the number or types of sutures involved or a history of craniofacial surgery.

CONCLUSIONS

Nasolacrimal duct obstruction is more common in patients with craniosynostosis compared to the general population. Having a putative syndrome or a putative genetic variant and female sex were risk factors for NLDO. Ophthalmic evaluations for all craniosynostosis patients and careful assessments of any symptoms of tearing are recommended.

Strabismus and refraction in non-syndromic craniosynostosis - A longitudinal study up to 5 years of age

PURPOSE

To evaluate the refractive outcome and strabismus at 5 years of age, in children operated for various types of non-syndromic craniosynostosis, and further analyse the refractive and strabismic development over time.

METHODS

Eighty-nine children, who had undergone operations for non-syndromic craniosynostosis, were examined at 5 years of age. These children also underwent ophthalmological examination preoperatively and up to 1 year after the operation. An age-matched control group including 32 healthy children was also recruited. Strabismus and eye motility were registered. Refraction was measured in cycloplegia.

RESULTS

There was a difference regarding the refractive outcome between the different types of craniosynostosis. Higher values of hypermetropia were found in the metopic craniosynostosis group on both eyes. In the unicoronal craniosynostosis group, high values of hypermetropia and a higher degree of astigmatism were found on the side contralateral to the craniosynostosis. Strabismus was found in 11/88 children of whom 10/11 had unicoronal craniosynostosis. A vertical deviation on the side ipsilateral to the fused suture was highly prevalent (6/10 cases). Ophthalmological dysfunctions were rare in children operated for sagittal craniosynostosis.

CONCLUSION

Ocular manifestations such as strabismus, astigmatism and anisometropia were highly prevalent in children operated for unilateral coronal craniosynostosis. Children operated for metopic craniosynostosis had higher rates of hypermetropia. The screening and follow-up protocols need to be tailored with regard to the type of craniosynostosis.

Ophthalmic Manifestations of Unilateral Coronal Synostosis

PURPOSE

To summarize the ophthalmic manifestations of unilateral coronal synostosis patients.

METHODS

We performed a literature search in the electronic database of PubMed, CENTRAL, Cochrane, and Ovid Medline guided by Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement for studies evaluating ophthalmic manifestations of unilateral coronal synostosis.

RESULTS

Unilateral coronal synostosis, also called unicoronal synostosis, may be mistaken for deformational plagiocephaly, an asymmetric skull flattening common in newborns. Characteristic facial features, however, distinguish the two. Ophthalmic manifestations of unilateral coronal synostosis include a "harlequin deformity", anisometropic astigmatism, strabismus, amblyopia, and significant orbital asymmetry. The astigmatism is greater on the side opposite the fused coronal suture. Optic neuropathy is uncommon unless unilateral coronal synostosis accompanies more complex multi-suture craniosynostosis. In many cases, surgical intervention is recommended; without intervention, skull asymmetry and ophthalmic disorders tend to worsen with time. Unilateral coronal synostosis can be managed by early endoscopic stripping of the fused suture and helmeting through a year of age or by fronto-orbital-advancement at approximately 1 year of age. Several studies have demonstrated that anisometropic astigmatism, amblyopia, and severity of strabismus are significantly lower after earlier intervention with endoscopic strip craniectomy and helmeting compared to treatment by fronto-orbital-advancement. It remains unknown whether the earlier timing or the nature of the procedure is responsible for the improved outcomes. As endoscopic strip craniectomy can only be performed in the first few months of life, early recognition of the facial, orbital, eyelid, and ophthalmic characteristics by consultant ophthalmologists enables expeditious referral and optimized ophthalmic outcomes.

CONCLUSION

Timely identification of craniofacial and ophthalmic manifestations of infants with unilateral coronal synostosis is important. Early recognition and prompt endoscopic treatment appears to optimize ocular outcomes.

Impact of the Craniofacial Surgery Simulation in Anterior Plagiocephaly on Orbits and Oculomotor Muscles: Biomechanical Analysis With a Finite Element Model

PURPOSE

The aim of this study was to show the displacements and strain induced by the supraorbital band advancement during a craniofacial surgery for an anterior plagiocephaly on the orbital bones and the orbital content thanks to a numerical surgical simulation using the finite element method.

METHODS

A three-dimensional (3D) finite element model of a child with an anterior plagiocephaly was entirely created from a tomodensitometry of a patient followed by our Craniofacial Pediatric team. Data of the tomodensitometry were computed with Slicer 3D to re-create the orbit geometry. Mesh production, properties of the model, and simulations of the fronto-orbital advancement were conducted on Hyperworks software (Altair Engineering, Inc., Detroit, MI, USA).

RESULTS

The resulting 3D Finite Element Model was used to perform the supraorbital advancement simulation. Displacement and strain patterns were studied for orbital bones, oculomotor muscles, and eyeballs. Relative high strain in the both trochlear area and excycloration of the right orbit are among the most interesting results as torsional strabismus as V-pattern strabismus are often described in children with an anterior plagiocephaly.

CONCLUSIONS

This pediatric Finite-Element Model of both orbits of a child with an anterior plagiocephaly showed the impact of the fronto-orbital advancement on the oculomotor system. This model described the relationship between the craniofacial surgery and the strabismus in the unilateral coronal synostosis. The advantages of this model are the many opportunities for improvement, including postoperative period and additional surgical procedures.