Optic canal characteristics in pediatric syndromic craniosynostosis

Skeletal expansion via craniofacial distraction osteogenesis technique in syndromic craniosynostosis: impact on ophthalmic parameters

BACKGROUND

This study aims to compare the changes in ophthalmic parameters among syndromic craniosynostosis patients who underwent craniofacial skeletal expansion procedures via distraction osteogenesis (DO).

METHOD

A retrospective study was conducted involving syndromic craniosynostosis patients who underwent surgical expansion via the DO technique from the year 2012 to March 2022. Changes in six parameters which consist of visual acuity, refractive error, optic disc health, intraocular pressure, degree of proptosis and orbital volume were measured objectively pre and post-surgery. For categorical parameters, the Chi-square cross-tab test was done. Paired sample T-test was used for normally distributed variables. Wilcoxon signed-rank test was used for non-normally distributed data.

RESULTS

Visual impairment was present in 21.4% of eyes before surgery and increased to 28.5% post-surgery. Three patients had changes of refractive error post-surgery with one developed hypermetropia, another developed anisometropia and the last had improvement to no refractive error. Two patients had optic disc swelling which was resolved post-surgery. Intraocular pressure changes were inconsistent post-surgery. All patients achieved a significant reduction in the degree of proptosis post-surgery. Orbital volume calculation using computed tomography (CT) scans shows a significant increase in volume post-surgery for all patients.

CONCLUSION

Our study shows a significant increase in orbital volume post-surgery with a reduction in the degree of proptosis. Optic disc and nerve health improved after the surgery. Changes in terms of visual acuity, refractive error and IOP were inconsistent after the surgical intervention.

Optic neuropathy in craniosynostosis

Craniosynostosis (CS) or the premature fusion of one or more cranial sutures in utero, or during the first years of life, can present in isolation or as a multisystem clinical disorder with a particular impact on visual function. Among ophthalmic complications, optic neuropathy is a significant cause of irreversible vision loss in these patients. Children with CS are at higher risk of developing elevated intracranial pressure which can lead to papilledema and, ultimately, optic atrophy. In addition, sometimes associated obstructive sleep apnea, abnormalities in central nervous system venous development, and Chiari malformation may contribute to optic neuropathy. Ophthalmologists have an important role in managing a number of coexistent ophthalmologic complications such as strabismus, anisometropia, amblyopia, ptosis, and exposure keratopathy in addition to maintaining surveillance for early signs of optic neuropathy; they play a critical consultative role contributing to the decision for primary or repeat decompressive surgery. In this article, we aim to review the etiology, diagnostic approach, and management of optic neuropathies in patients with craniosynostosis.

Characterization of cranial growth patterns using craniometric parameters and best-fit logarithmic growth curves

Few studies have reported a complete quantitative database of cranial growth, from infancy to adulthood, as a reference through three-dimensional analysis. Our study aimed to characterize cranial growth patterns using craniometric parameters by establishing sex- and age-specific norms. In total, 1009 Korean patients (male-to-female ratio, 2:1; age range, 0-18 years) who underwent thin-slice computed tomography (CT) scans for head trauma were divided into 20 age groups, with a 6-month interval for those under 2 years and a 1-year interval for those over 2 years. After four reference planes [Frankfurt horizontal (FH), midsagittal, and two coronal planes passing the sella (S) and basion (B)] had been established, intracranial volume (ICV), anteroposterior diameter (APD), biparietal diameter (BPD), cranial heights (CHs), cephalic index (CI, BPD/APD), and height index (HI, CH-B/APD) were measured using Mimics software. Best-fit logarithmic curves were derived using a linear regression model. The best-fit curves for ICV (cm3) were y = 785.6 + 157*ln(age) for males (R2 = 0.5752) and y = 702 + 150.5*ln(age) for females (R2 = 0.6517). After adjustment for age, males had higher values of ICV, APD, BPD, and CHs than females (all p < 0.0001). ICV, APD, BPD, and CHs demonstrated a rapid increase during the first few months of life, reaching 90-95% of the adult size by 5-6 years of age, while CI and HI showed a continuous decline by 4%, regardless of sex. This study presented cranial growth references for more than 1000 of the Korean population aged up to 18 years. This might help to provide guidelines for diagnosis and treatment (including timing, amount, and direction) for cranial reconstruction in pediatric patients with craniosynostosis.

Morphometric and morphological evaluation of the optic canal in three different parts in MDCT images

PURPOSE

This study aimed to classify the morphometry and variations of optic canal by examining its changes according to gender and body side, and developments according to age.

METHODS

We retrospectively evaluated the orbit and paranasal sinus computerized tomography images of 200 individuals (age range 3 months-90 years;106 female, 94 male). In this study, three different parts of optic canal in evaluated morphometric and morphological.

RESULTS

The intracranial aperture was found to be statistically significantly wide in males than females on both sides (p ˂ 0.05). When optic canal types were evaluated, the most common type among healthy individuals was conical type (right: 68%, left:67.5%), and the least common type was irregular type (right and left:1.5%). According to the type of optic waist, the most common was triangle type.

CONCLUSION

Considering the possible effect of optic canal size on pathologies, it is important to establish a basis for the parameters of this structure in healthy individuals. In this study, both the morphology and morphometry of the canal as well as variations were examined and it was determined that the structure was affected by gender, body side and age group. Knowledge of anatomic morphometry, variations and complexities arising from these are important for clinical diagnosis and management.