The ophthalmic sequelae of Pfeiffer syndrome and the long-term visual outcomes after craniofacial surgery

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.

Prevalence of Ocular Anomalies in Craniosynostosis: A Systematic Review and Meta-Analysis

Background: The aim of this study was to describe the ophthalmic abnormalities and their prevalence in craniosynostosis prior to craniofacial surgery. Methods: A systematic search was conducted on Medline OVID, Embase, Cochrane, Google Scholar, Web of Science Core Collection. Inclusion criteria were English papers, children aged <18 years with non-syndromic and syndromic craniosynostosis, case reports, case series, and case-control studies. A system of domains was established consisting of an anatomic and functional ophthalmic domain. A meta-analysis of single proportions was carried out using random effects model and pooled mean proportions with 95% confidence intervals (CI) were calculated. Results: Thirty-two papers analyzing 2027 patients were included. Strabismus was the most common anomaly in non-syndromic craniosynostosis: Horizontal strabismus was highest prevalent in unicoronal craniosynostosis (UCS) 19% (95% CI 9–32), followed by vertical strabismus 17% (95% CI 5–33). In syndromic craniosynostosis, horizontal strabismus was most prevalent in Crouzon syndrome 52% (95 CI 26–76), followed by Apert syndrome 50% (95% CI 42–58). Vertical strabismus was most prevalent in Saethre-Chotzen 60% followed by Muenke’s syndrome 36%. Furthermore, astigmatism was the second most reported outcome in non-syndromic craniosynostosis and highest prevalent in UCS 35% (95% CI 21–51). In syndromic craniosynostosis, astigmatism was most frequently seen in Crouzon syndrome 43% (95% CI 22–65), followed by Apert syndrome 34% (95% CI 14–58). Moreover, in syndromic craniosynostosis, 5–40% had a decrease in visual acuity (VA) ≤ 0.3 LogMAR in the better eye and 11–65% had a VA ≤ 0.3 LogMAR in at least one eye. Discussion: This review demonstrates the high prevalence of ocular anomalies in non-syndromic and syndromic craniosynostosis. A multidisciplinary and systematic approach is needed for the screening and optimal treatment of these conditions in a timely manner.

Orbital and Periorbital Dysmorphology in Untreated Pfeiffer Syndrome

BACKGROUND

Visual impairment secondary to orbital and periorbital dysmorphology is frequent in Pfeiffer syndrome patients. The etiopathogenesis of this aberrancy, however, remains unclear.

METHODS

Untreated Pfeiffer syndrome patients (n = 31) and normal control subjects (n = 43) were compared. Craniometric and volumetric analyses related to the orbital and periorbital anatomy were performed using Materialise (Leuven, Belgium) software.

RESULTS

Overall, orbital cavity volume of Pfeiffer patients is reduced by 28 percent (p < 0.001), compared to normal, starting before 3 months of age (p = 0.004). Globe volume was diminished by 10 percent (p = 0.041) before 3 months of age, yet tended to catch up thereafter. However, the retrobulbar soft-tissue volume remained smaller beyond 1 year of age (17 percent, p = 0.003). Globe volume projection beyond the bony orbit increased in all observed ages (82 percent, p < 0.001). The volumes of sphenoid bone, maxilla, and mandible proportionately were restricted by 24 to 25 percent (p = 0.003 to 0.035) before 3 months of age. The volume of maxilla and mandible gradually approximate normal; however, the sphenoid bone volume in Pfeiffer patients remains less than normal (p = 0.002) into childhood. The anteroposterior length of both the zygoma and the maxilla was reduced by 14 percent (p < 0.001). Anterior positioning of the zygoma is less by 23 percent (p < 0.001) in Pfeiffer patients overall, with anterior positioning of maxilla reduced similarly by 23 percent (p < 0.001).

CONCLUSIONS

Pfeiffer syndrome patients develop decreased retrobulbar soft-tissue and globe volume, along with a restricted orbital cavity volume in infancy. Significant hypoplasia of the sphenoid bone is associated with more severe central facial (maxilla) retrusion, compared to lateral facial structures (zygoma).

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Case Report: Anisometropic Astigmatism Secondary to Unilateral Coronal Synostosis

SIGNIFICANCE

This case highlights the importance of performing a cycloplegic examination, including retinoscopy, on infants with the diagnosis of craniosynostosis because of the risk of refractive amblyopia.

PURPOSE

This report presents the unique case of an infant with amblyogenic anisometropic astigmatism secondary to unilateral coronal synostosis, which resolved after fronto-orbital advancement.

CASE REPORT

A 4-month, 14-day-old male infant with right unilateral coronal synostosis associated with Pfeiffer syndrome presented to the clinic with anisometropic astigmatism (right eye, +2.00 diopter sphere; left eye, +4.00 -4.75 ×170). Because of his young age, this refractive error was initially monitored. Upon follow-up examination at 6 months of age, he showed stability in his refractive error and early signs of amblyopia. Glasses were prescribed and amblyopia resolved. After cranial surgery, the patient's orbits were symmetric, and his amblyogenic astigmatism resolved.

CONCLUSIONS

Patients who present to the clinic with craniosynostosis should undergo cycloplegic examinations, including retinoscopy, early in their care with the knowledge that these patients can require interventions such as glasses and amblyopia treatment.

Effect of Fibroblast Growth Factor 2 on Extraocular Muscle Structure and Function

Purpose

Mutations in the fibroblast growth factor (FGF) receptor can result in strabismus, but little is known about how FGFs affect extraocular muscle structure and function. These were assessed after short-term and long-term exposure to exogenously applied FGF2 to determine the effect of enhanced signaling.

Methods

One superior rectus muscle of adult rabbits received either a series of three injections of 500 ng, 1 µg, or 5 µg FGF2 and examined after 1 week, or received sustained treatment with FGF2 and examined after 1, 2, or 3 months. Muscles were assessed for alterations in force generation, myofiber size, and satellite cell number after each treatment.

Results

One week after the 5 µg FGF2 injections, treated muscles showed significantly increased force generation compared with naïve controls, which correlated with increased myofiber cross-sectional areas and Pax7-positive satellite cells. In contrast, 3 months of sustained FGF2 treatment resulted in decreased force generation, which correlated with decreased myofiber size and decreased satellite cells compared with naïve control and the untreated contralateral side.

Conclusions

FGF2 had distinctly different effects when short-term and long-term treatments were compared. The decreased size and ability to generate force correlated with decreased myofiber areas seen in individuals with Apert syndrome, where there is sustained activation of FGF signaling. Knowing more about signaling pathways critical for extraocular muscle function, development, and disease will pave the way for improved treatment options for strabismus patients with FGF abnormalities in craniofacial disease, which also may be applicable to other strabismus patients.

Ophthalmic features of craniosynostosis: A Malaysian experience

BACKGROUND

This study aims to collect local Malaysian data regarding the ophthalmic features and complications in craniosynostosis patients who attended the Combined Craniofacial Clinic (CFC) in University Malaya Medical Centre (UMMC).

METHODS

Retrospective study of medical notes of craniosynostosis patients who attended the CFC in UMMC from 2014 to December 2020.

RESULTS

Out of 37 patients, 29 had syndromic craniosynostosis, and 8 had non-syndromic craniosynostosis. Visual impairment was present in 32.1% of patients. Causes for visual impairment were as follows - amblyopia (25.0%), exposure keratopathy (3.6%), and optic atrophy (3.6%). Hypermetropia and myopia were each seen in 20.6% of patients. Astigmatism was seen in 47.1% of patients, and 29.1% had anisometropia. Proptosis was present in 78.6% and lagophthalmos in 53.3% of patients. Strabismus in primary position occurred in 51.7% of patients. Thirty-one percent of the patients had exposure keratopathy. Optic disc atrophy was seen in 13.7% of patients, and 8.3% had optic disc swelling. Optic disc swelling was resolved in all patients who underwent craniofacial surgery.

CONCLUSION

Our experience in Malaysia was consistent with previously reported data on ophthalmic features of craniosynostosis patients. Additionally, we found that non-syndromic craniosynostosis patients are also at risk of ocular complications just as much as syndromic patients. Appropriate treatment of amblyogenic risk factors, ocular complications, and timely detection of papilledema, and prompt surgical intervention are crucial in preserving long-term visual function in these patients.

Ocular biometric features of pediatric patients with fibroblast growth factor receptor-related syndromic craniosynostosis

Ametropia is reported as a common ophthalmic manifestation in craniosynostosis. We retrospectively compared childhood refractive error and ocular biometric features of fibroblast growth factor receptor (FGFR)-related syndromic craniosynostosis patients with those of non-syndromic craniosynostosis and control subjects. Thirty-six eyes (18 patients) with FGFR-related syndromic craniosynostosis, 76 eyes (38 patients) with non-syndromic craniosynostosis, and 114 eyes (57 patients) of intermittent exotropes were included in the analysis. Mean age at examination was 7.82 ± 2.51 (range, 4–16) years and mean spherical equivalent was -0.09 ± 1.46 Diopter. Mean age and refractive error were not different between groups, but syndromic craniosynostosis patients had significantly longer axial length, lower corneal power, and lower lens power than other groups (p < 0.01, p < 0.01, and p < 0.01, respectively). Axial length was positively correlated and keratometry and lens power were negatively correlated with age in non-syndromic craniosynostosis and controls, while these correlations between age and ocular biometric parameters were not present in the FGFR-related syndromic craniosynostosis. In conclusion, ocular biometric parameters in FGFR-related syndromic craniosynostosis differed from those of non-syndromic craniosynostosis and age-matched controls, and did not show the relations with age, suggesting this cohort may have abnormal refractive growth.

Analysis of complications following multidisciplinary functional intervention in paediatric craniomaxillofacial deformities

Paediatric craniomaxillofacial (CMF) surgery requires a multidisciplinary team approach to ensure the optimal and holistic management of children with craniofacial deformities. The aim of this retrospective study was to analyse the complications following functional interventions among 34 CMF deformity patients in a single multidisciplinary craniofacial centre. Electronic data including patient demographic characteristics and clinical entry were analysed. Inclusion criteria were all paediatric patients with CMF deformities who underwent various functional interventions. A total of 64 interventions (48 intermediate and 16 definitive) were conducted. Based on the Sharma classification of complications, 20.3% were type I, 4.7% were type II, 1.6% were type III, and 4.7% were type IV . Most complications were type I, which included local infection (3.1%) and premature opening of tarsorrhaphy (3.1%). More serious complications (types III and IV) included temporary visual loss (1.6%) and intraoperative haemorrhage (1.6%). Although a low complication rate was observed in intermediate interventions, a higher complication rate was observed in more complex definitive interventions such as monobloc distraction osteogenesis. Although most complications were manageable, effective prevention remains mandatory, as serious complications may lead to permanent damage and mortality. This analysis highlights the importance of a multidisciplinary team approach to optimize the outcomes in CMF patient management.

Ophthalmological outcomes of unilateral coronal synostosis in young children

BACKGROUND

To report refractive outcomes, describe types of strabismus and evaluate the outcomes of surgical intervention for unilateral coronal synostosis (UCS) in paediatric patients.

METHODS

This study retrospectively included 30 UCS cases. Patients aged from 3 months to 6 years (median: 1.8 years) were enrolled from January 2018 to December 2019 at Shanghai Children's Hospital. Sixteen patients had all types of strabismus; 15 of these patients underwent surgery.

RESULTS

Refractive errors of 30 cases were included. In 60% of patients, astigmatism of 1.00D or more existed in not less than one eye at last record. Twenty (66.7%) patients had the larger amount of astigmatism in the contralateral eye. Fifteen patients received strabismus surgery, of whom 6 patients with monocular elevation deficiency (MED) underwent the standard Knapp procedure, with or without a horizontal deviation procedure. Fifteen cases were horizontally aligned within 5 prism dioptres (Δ). Six patients with MED (100%) had attained ≥25% elevation improvement after surgery, and the vertical deviation decreased from 25.83 Δ ± 4.92 Δ (range, 20 Δ-30 Δ) to 0.83 Δ ± 4.92 Δ after surgery (range, 0 Δ-10 Δ), for an improvement of 26.67 Δ ± 4.08 Δ (t = 16 P < 0.05). In 1 patient with esotropia, the horizontal deviation decreased from + 80 Δ to + 5 Δ after surgery. One patient was diagnosed with trichiasis and one with contralateral lacrimal duct obstruction.

CONCLUSIONS

Contralateral MED was also the main type of strabismus in UCS. Superior oblique muscle palsy was still the most common, as previously reported. There is a risk of developing a higher astigmatism and anisometropia in the contralateral eye to synostosis. Other ophthalmic disorders should be treated in a timely manner.

TRIAL REGISTRATION

The study was approved by the Institutional Review Board of Shanghai Children's Hospital (approval No. 2020R023-E01) and adhered to the tenets of the Declaration of Helsinki. Ethics approval was procured on March 30, 2020. This was a retrospective study. Written informed consent was sought from the patients' parents or legal guardians. Clinical Trials Registry number: ChiCTR2000034910 . Registration URL: http://www.chictr.org.cn/showproj.aspx?proj=56726 .

Craniosynostosis and oculomotor disorders

Simple, complex or syndromic craniosynostosis may be responsible for ocular and especially oculomotor pathologies. Among simple craniosynostosis, anterior plagiocephaly is the most frequently associated with oculomotor disorders. Oculomotor disorders encountered in craniosynostosis are specific to this pathology. They may be related to orbital deformities or oculomotor muscle malformations. Early craniofacial surgery reduces the onset and severity of these oculomotor disorders which is very important for ophtalmological patient care. Indeed, these oculomotor disorders are difficult to treat for the ophthalmologist with most of the time several surgeries needed, and lead to amblyopia if neglected.

Clinical genetics of craniosynostosis

PURPOSE OF REVIEW

When providing accurate clinical diagnosis and genetic counseling in craniosynostosis, the challenge is heightened by knowledge that etiology in any individual case may be entirely genetic, entirely environmental, or anything in between. This review will scope out how recent genetic discoveries from next-generation sequencing have impacted on the clinical genetic evaluation of craniosynostosis.

RECENT FINDINGS

Survey of a 13-year birth cohort of patients treated at a single craniofacial unit demonstrates that a genetic cause of craniosynostosis can be identified in one quarter of cases. The substantial contributions of mutations in two genes, TCF12 and ERF, is confirmed. Important recent discoveries are mutations of CDC45 and SMO in specific craniosynostosis syndromes, and of SMAD6 in nonsyndromic midline synostosis. The added value of exome or whole genome sequencing in the diagnosis of difficult cases is highlighted.

SUMMARY

Strategies to optimize clinical genetic diagnostic pathways by combining both targeted and next-generation sequencing are discussed. In addition to improved genetic counseling, recent discoveries spotlight the important roles of signaling through the bone morphogenetic protein and hedgehog pathways in cranial suture biogenesis, as well as a key requirement for adequate cell division in suture maintenance.