ISCFS 2019 Abstract Supplement
S12-02 SESSION 12: FACIOCRANIOSYNOSTOSIS – PART II OPTIC NERVE STRETCHING DURING FRONTO-FACIAL MONOBLOC ADVANCEMENT FOR CROUZON SYNDROME
Introduction: Fronto-facial advancement results in a forward movement of the eyes. The effects of this procedure on the optic nerves has not been studied so far. Here we assessed - using different morphometric methods - the length and the perimeter variations of the optic nerve before and after fronto-facial monobloc advancement with internal distraction in Crouzon syndrome.
Methods: We included 25 patients with Couzon syndrome who benefited from fronto-facial monobloc advancement at various ages. We collected CT-scans at 4 time points: (1) pre-operative, (2) early post-operative and (3) late post-operative. Optic nerve were segmented using Mimics (Materialise) and Avizo (Thermo Fisher Scientific). We measured the linear and curved length of the optic nerve, as well as the variations of the perimeter of the optic nerve along its length. Values in Crouzon syndrome were compared to values obtained from an age-matched control group of 30 patients without craniofacial conditions. Results were analysed using linear and logistic mutlivariate models.
Results: We showed that fronto-facial monobloc advancement with internal distraction does not increase significantly the length of the optic nerve, even though there is trend for increase of the curved length of the nerve. Fronto-facial surgery nevertheless induces a specific modification of the optic nerve perimeter with a midline thinning, witnessing the longitudinal streching of the nerve.
Conclusion: Fronto-facial surgery has a moderate but significant morphological effect on the optic nerve. Further finite element analyses of the optic nerve based on our preliminary results will contribute to understand the response of this structure to mechanical forces, with potential implications for a better understanding of optic nerve damage in craniofacial trauma.Copyright © 2019 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of The American Society of Plastic Surgeons. All rights reserved.