Emergency Optic Canal Decompression for Vision Salvage in Fibrous Dysplasia

The Natural History of Fibrous Dysplasia of the Orbit

BACKGROUND

Orbital fibrous dysplasia (FD) is a disease of disordered fibro-osseous proliferation secondary to altered osteogenesis, with potential sequelae including compressive neuropathy and irreversible vision loss. The purpose of this study was to evaluate the natural history and longitudinal outcomes of 37 patients with orbital FD who underwent stratified surgical management.

METHODS

All patients treated for FD from 2015 to 2021 were identified, yielding 185 patients, 39 with orbital involvement. Impressions from head computed tomographic scans were analyzed by a craniofacial radiologist to evaluate location and timing of tumor growth. Operative records were reviewed to determine surgical approach (partial excision/contouring, complete excision, or partial excision with optic nerve decompression).

RESULTS

The average patient age at diagnosis was 10.7 ± 4.5 years, and the average follow-up was 5.2 ± 4.7 years. Of the 37 patients with orbital involvement, 28 (75.7%) had optic canal involvement. Of those with optic canal involvement, 13 (46.4%) required partial excision with optic nerve decompression, whereas 15 (53.6%) did not. Of those without optic canal involvement, two patients (22.2%) underwent partial excision/contouring of the anterior orbit to correct dystopia and/or proptosis, and four patients (44.4%) underwent complete excision of the orbital component and reconstruction with bone graft or mesh. Younger age at diagnosis was associated with an increased number of surgical interventions ( P = 0.011), younger age at first optic canal decompression ( P = 0.003), and worse visual outcomes ( P = 0.009).

CONCLUSION

In the authors' cohort, patients diagnosed at a younger age required more operations, underwent decompression earlier, and had worse visual outcomes.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Craniofacial Fibrous Dysplasia in Fronto-Orbital Region: A Single-Center Retrospective Study of 38 Cases

OBJECTIVE

This study presents the clinical characteristics, imaging manifestations, and surgical experience in 38 patients diagnosed with craniofacial fibrous dysplasia in fronto-orbital region (foFD).

METHODS

We retrospectively analyzed the clinical data from 38 patients who had surgery for foFD. The surgical procedure typically involved extensive tumor removal, followed by immediate reconstruction of the frontal bone and orbit using synthetic materials. Additionally, 9 patients underwent simultaneous microscopic decompression of the optic canal.

RESULTS

Common clinical manifestations included progressive fronto-orbital bone deformity (35), proptosis (28), orbital dystopia (21), and visual impairment (9). The disease primarily affecting the frontal bone (38), the sphenoid bone (28), and the ethmoid bone (24). The optic canal was involved in 9 patients with functional impairment. Computed tomography scans in all 38 cases revealed satisfactory repair material positioning and complete resolution of frontal deformities. Among the 9 patients who underwent optic canal decompression, 7 experienced partial recovery of visual acuity after surgery.

CONCLUSIONS

In the surgical treatment of foFD, it is crucial to achieve maximal bone resection and repair skull defects, while decompressing the optic canal can provide significant benefits for patients with decreased visual function preoperatively. The use of preformed artificial materials offers advantages in aesthetic restoration after lesion excision.

Bilateral chiasm and optic nerve micro-decompression in a child with extensive cranial fibrous dysplasia: how I do it

BACKGROUND

Surgical decompression to the optic-chiasmatic region in craneofacial fibrous dysplasia (CFD) must be performed safely to improve or stabilize visual loss.

METHOD

We describe a technical nuance when facing on a huge, deformed skull with potentially imbricated dura mater. Craniectomy was performed in concentric arches allowing to expose surgical field and elevated step by step. Bilateral micro-decompression was performed after without difficulties.

CONCLUSIONS

Decompressing both optic nerves using this technique is safe and relatively simple to perform.

Optic disc edema in fibrous dysplasia/McCune-Albright syndrome: Prevalence, etiologies, and clinical implications

BACKGROUND

Fibrous dysplasia (FD) is a rare disorder of expansile fibro-osseous lesions that may be associated with extraskeletal features as part of McCune-Albright syndrome (MAS). Optic disc edema is a potentially serious ophthalmologic finding that has been rarely reported in patients with FD/MAS. The purpose of this study was to investigate the prevalence and potential clinical associations of optic disc edema in a large cohort.

METHODS

Clinical records were reviewed from subjects in an ongoing FD/MAS natural history study. Computed Tomography scans were evaluated for the presence of structural craniofacial abnormalities associated with optic disc edema, including Chiari I malformation and space-occupying lesions. Craniomorphometric analyses were performed to determine optic canal diameter and intracranial volume. Statistical analyses were performed to compare clinical and radiographic features between subjects with and without optic disc edema.

RESULTS

Optic disc edema was diagnosed in 7/187 subjects, for a prevalence of 3.7%. All subjects with optic disc edema were diagnosed before age 18 years and had mild, non-progressive disease. Radiographic structural abnormalities, including Chiari I malformation, aneurysmal bone cysts, and arachnoid cysts, were associated with higher odds of optic disc edema (odds ratio [OR] 24.3; 95% confidence interval [CI], 4.2 to 121.4; p < 0.01) (OR 18.0; 95% CI, 3.4 to 108.2; p < 0.01). Treatment with leuprolide, a gonadotropin releasing hormone analog, was also associated with optic disc edema (OR 26.0; 95% CI 3.3 to 177.5; p < 0.05). There was no significant association of optic disc edema with other MAS endocrinopathies, medications, optic canal diameter, or intracranial volume.

CONCLUSION

Optic disc edema is an uncommon but potentially serious complication of craniofacial FD, which may occur more frequently in pediatric patients and those with structural craniofacial abnormalities. The potential association of leuprolide therapy with optic disc edema in this population warrants further study.

Fibrous dysplasia of the orbital region: Series of 12 cases and review of the literature

PURPOSE

Fibrous dysplasia (FD) is a benign fibro-osseous developmental disorder of growing bone, sometimes involving the craniofacial skeleton (CFD). We wish to present a patient series with CFD of the orbital region and discuss treatment modalities.

METHODS

Twelve patients were referred for orbital CFD in the Nantes University Hospital between 2000 and 2018 and studied according to the clinical parameters, radiological features, and modalities of treatment.

RESULTS

The mean age was 25.6 years. Ten patients exhibited facial asymmetry with vertical globe dystopia (75%), proptosis (58%) and facial bump (50%). The disease was monostotic in 83% of patients, involving the frontal bone (25%), the sphenoidal bone (33%), the fronto-sphenoidal complex (25%), and the skull base (17%). Unilateral radiological proptosis was found in 7 patients, with a mean protrusion 3.9mm. The optic canal was involved in 75% of patients, with no functional impairment. Three patients were treated with bisphosphonate therapy to stop progression of the disease; 6 patients were given a bone remodelling procedure with good aesthetic outcomes.

CONCLUSION

The orbit is a rare localization for FD causing aesthetic and functional disabilities. Medical and surgical treatment can be proposed as part of a multidisciplinary approach.

Navigation-assisted endonasal endoscopic optic nerve decompression in fibrous dysplasia

A 12-year-old girl presented with left-sided decreased vision of 2-month duration. Clinical evaluation and imaging revealed fibrous dysplasia compressing the left optic nerve with no underlying endocrinological abnormalities. Best-corrected visual acuity showed progressive deterioration of vision over 2-month follow-up. She underwent navigation-assisted endonasal endoscopic optic nerve decompression. Post-surgery there was improvement in vision and it became normal (6/6). Six-month follow-up showed stable vision with no further complications.