Optic Nerve Decompression for Orbitofrontal Fibrous Dysplasia: Recent Development of Surgical Technique and Equipment

Abstract

Objectives: Orbitofrontal fibrous dysplasia often involves the bony orbit and optic canal. Although fibrous dysplasia reportedly produces compression of the optic nerve leading to visual disturbances, optic nerve decompression in patients without clinical signs of optic neuropathy remains controversial. We describe the recent development of surgical techniques and equipment for optic nerve decompression in orbitofrontal fibrous dysplasia. Methods: Optic nerve decompression was performed prophylactically for five patients and therapeutically for one patient using the transcranial extradural route. A high-speed drill and continuous suctionirrigation system has been used in five patients since 1998, and an ultrasonic bone curette in two patients since 2004. Results: The continuous suction-irrigation system was particularly effective for decreasing heat transfer and thus preventing thermal injury to the optic nerve from the high-speed drill. The ultrasonic bone curette was also effective, allowing bone removal with minimal pressure from the tip of the handpiece and without catching cotton pledgets or damaging surrounding tissues. Orbital dystopias and craniofacial deformities induced by fibrous dysplasia were also successfully corrected. Postoperatively, disturbance in visual function was present in only two patients. Mean follow-up period was 4.9 years. Conclusions: This equipment may contribute to the development of new modalities for optic nerve decompression in orbitofrontal fibrous dysplasia.

Study on the treatment of traumatic orbital apex syndrome by nasal endoscopic surgery

“…There is literature available on treatment of patients with optic nerve injuries using a high dose of hormones and certain satisfactory results achieved in it, but according to the statistics, the effectiveness of this single medication treatment was much lower than that of comprehensive treatment with the surgery as the main therapy [10,[13][14][15][16][17][18][19][20][21][22]. In addition to that, patients with OAS were severely injured and the orbital apexes and the optic canals were obviously compressed by the fractures; therefore, surgical procedures are very necessary to treat OAS [23][24][25].…”

Craniofacial Fibrous Dysplasia Involving the Orbit

“…Optic nerve decompression is generally recommended only in orbital involvement causing symptomatic optic nerve impingement. 1,20,22 A retrospective review by Abe et al 20 suggested that the unilateral frontotemporal extradural approach for decompressive surgery as seen in our patient may be superior to other approaches.…”

“…19 Other theories regarding the pathogenesis of visual impairment in FD have been proposed, including traction on the optic nerve, spontaneous hemorrhage, and external compression of optic canal contents by a separate cystic lesion, such as a mucocele. 10,13,15,18,20 Growth hormone excess in FD has also been associated with optic neuropathy. Therefore, screening for growth hormone excess should be done in all patients with craniofacial FD as it is treatable.…”

Surgery versus Watchful Waiting in Patients with Craniofacial Fibrous Dysplasia: A Meta-Analysis

“…ONC can result from primary CFD of the sphenoid bone or from secondary lesions, including cystic FD, mucoceles, hemorrhage, and aneurysmal bone cysts [27]. While there is consensus that therapeutic decompression of the optic nerve is indicated for symptomatic patients, the question of whether to operate on asymptomatic patients is an ongoing controversial issue [6,8,13,36]. Earlier studies had reported visual impairment in 20-80% of patients with ONC [19,23].…”

“…Criteria for study population inclusion were histopathologic diagnosis of CFD, radiologically confirmed optic canal narrowing, pre-and post-treatment visual status (based on visual fields and visual acuity), and .4 months of follow-up. The included studies are listed in Tables S1, S2, S3 (supplementary material) [8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33]. Follow-up included periodic (6-12 months) radiological imaging with CT and MRI as well as ophthalmologic exams.…”