A long-term visual outcome comparison in patients with optic nerve sheath meningioma managed with observation, surgery, radiotherapy, or surgery and radiotherapy

Treatment of Meningiomas Involving the Optic Canal with Endoscopic Transnasal Decompression of the Optic Nerve

BACKGROUND

Management of patients with optic nerve sheath meningiomas (ONSMs) is controversial and the treatment strategy in this patient group is still up for discussion. Transnasal endoscopic orbital and optic nerve decompression aims to reduce the pressure in the orbit and on the optic nerve and thereby prevent vision loss. This article presents material from 7 cases of transnasal endoscopic orbital decompression.

METHODS

The study design is a retrospective cohort study. The aim was to include all patients with a meningioma residing along the nerve sheath and who were operated using endoscopic transnasal decompression of the orbit and if needed the optic canal at Odense University Hospital. Data from the medical records were collected and pre- and postoperative eye examinations were compared. In addition, it was recorded whether there were complications to the procedure and whether additional treatments were given.

RESULTS

In total, 4 women and 3 men were included in the study. Four out of 7 patients experienced improvement in vision after the operation. One patient experienced unchanged vision and 2 patients experienced deterioration of vision after surgery.

CONCLUSIONS

The current report of 7 patients with ONSM shows promising results for this surgical procedure as 4 out of 7 patients experienced improvement in their vision at follow-up examinations. The 2 patients who experienced deterioration of vision already had severely reduced vision preoperatively, which indicates that surgery should be considered before the vision becomes significantly reduced.

Does Adjuvant Gamma Knife Stereotactic Radiosurgery Have a Role in Treating Optic Nerve Sheath Meningiomas?

BACKGROUND

Meningiomas arising from or adjacent to the optic nerve sheath meningioma (ONSM) are management challenges because of their risk of visual loss. Stereotactic radiosurgery (SRS) is a minimally invasive modality that can be added as adjuvant treatment for patients whose tumor has progressed or recurred after initial resection.

METHODS

The authors retrospectively reviewed 2,030 meningioma patients who underwent SRS between 1987 and 2022. In total, 7 patients (4 females; median age = 49) were found with tumors originating from the optic nerve sheath. None of the patients had tumors that engulfed the optic nerve as such tumors typically undergo fractionated radiation therapy (FRT) to preserve vision. The clinical history, visual function, and radiographic and neurological findings were characterized. Outcome measures included visual status, tumor control, and the need for additional management.

RESULTS

All patients underwent either initial gross total (n = 1) or partial surgical resection (n = 6) before SRS. Two patients with progressive tumor growth also had SRS after failing additional fractionated radiation after surgery (54 Gy, 30 fractions for both patients). The median time between the date of surgery and the SRS procedure date was 38 months. The Leksell Gamma Knife was used to deliver a margin dose of 12 Gy (range: 8-14 Gy) to a median cumulative tumor volume of 3.3 cc (range: 1.2-18 cc). The median maximal optic nerve radiation dose was 6.5 Gy (range: 1.9-8.1 Gy). After SRS, the median follow-up time was 130 months (range: 26-169 months). Two patients showed local tumor progression at 20 and 55 months after SRS. Four had stable visual function, 2 experienced improved visual acuity, and 1 patient had visual deterioration.

CONCLUSIONS

Meningiomas arising from (but not engulfing the optic nerve) represent management quandaries after failed initial surgical removal. In this experience, salvage SRS was associated with tumor control and vision preservation in 5 of 7 patients. Additional experience with this strategy may further define the role of SRS both as a salvage and primary option.

Role of hypofractionated stereotactic radiotherapy for primary optic nerve sheath meningioma

Background

Optic nerve sheath meningiomas (ONSM) are rare tumors potentially causing visual deficits. This study aims to report the anatomic and visual outcomes of patients with primary ONSM treated with hypofractionated stereotactic radiotherapy (HF-SRT).

Methods

Data of 36 patients treated with HF-SRT between 2008 and 2019 were retrospectively collected. The clinical target volume (CTV) was equal to the gross tumor volume and a 2 mm was added for the planning target volume. All responses other than progression were accepted as local control (LC). The VA grading was performed under 3 groups to provide an even distribution; 20/400 or worse, 20/40-20/400, and 20/40 or better.

Results

Median HF-SRT dose was 25 Gy and the median CTV was 1.94 cc. After a median of 106 months of follow-up, the tumor regressed in 23 (64%), was stable in 9 (25%), and progressed in 4 (11%) eyes. The overall rate of LC was 89% with 2-, 5-, 10-, and 15-year rate of 100%, 94%, 84%, and 84%, respectively. Treatment-related late toxicity rate was 11%. The VA was stable in 27 (75%) eyes, improved in 5 (14%) eyes, and worsened in 4 (11%) eyes, respectively, after HF-SRT. Female gender was the only independent predictor of an improved VA.

Conclusions

Hypofractionated stereotactic radiotherapy is a safe and satisfactory treatment option for primary ONSM without severe toxicity. It may be advisable to commence treatment before an established visual deficit of 20/400 or worse occurs, to make the most of the functional benefit.

Visual Outcomes Following Surgical Debulking in Exophytic Optic Nerve Sheath Meningiomas

PURPOSE

To report a case of a globular primary optic nerve sheath meningioma managed surgically with improvement in vision and review the literature for outcomes of purely intraorbital exophytic-globular primary optic nerve sheath meningiomas managed surgically.

METHODS

A literature review was conducted using Google Scholar and PubMed with the search terms "primary optic nerve sheath meningioma," "surgery," "exophytic," and "globular." Articles were included if they were available in English. Individual cases from the reviewed articles were included if the tumor was purely intraorbital with a globular or exophytic morphology, was managed with total or subtotal surgical excision, and visual outcomes were reported. Cases were excluded if the tumor extended intracanalicularly or intracranially, tumor morphology was unknown, or surgical management consisted of biopsy, optic nerve sheath decompression, or optic canal decompression rather than tumor debulking.

RESULTS

A total of 28 patients with intraorbital globular-exophytic primary optic nerve sheath meningiomas managed surgically have been reported in the literature. Vision improved in 29% (n = 8/28) and remained stable in 43% (n = 12/28) of patients. Furthermore, patients with good (Snellen notation ≥ 0.5) vision (n = 10) typically retained good vision postoperatively and at follow-up, with 1 patient experiencing a decline to poor (Snellen ≤0.1) vision at the last follow-up (92 months postoperatively). Similarly, patients with fair (Snellen notation >0.1 and <0.5) vision (n = 5) often improved to good vision (n = 3) or stayed at fair vision (n = 1), with 1 declining to poor vision at postoperative hospital discharge.

CONCLUSIONS

Surgical management of exophytic or globular optic nerve meningiomas does not universally lead to vision loss and may be appropriate in select patients.

Radiotherapy for Meningioma

Meningiomas are the most common primary intracranial brain tumor, and have a heterogeneous biology and an unmet need for targeted treatment options. Existing treatments for meningiomas are limited to surgery, radiotherapy, or a combination of these depending on clinical and histopathological features. Treatment recommendations for meningioma patients take into consideration radiologic features, tumor size and location, and medical comorbidities, all of which may influence the ability to undergo complete resection. Ultimately, outcomes for meningioma patients are dictated by extent of resection and histopathologic factors, such as World Health Organization (WHO) grade and proliferation index. Radiotherapy is a critical component of meningioma treatment as either a definitive intervention using stereotactic radiosurgery or external beam radiotherapy, or in the adjuvant setting for residual disease or for adverse pathologic factors, such as high WHO grade. In this chapter, we provide a comprehensive review of radiotherapy treatment modalities, therapeutic considerations, radiation planning, and clinical outcomes for meningioma patients.

Diagnostic and Therapeutic Strategy in Anaplastic (Malignant) Meningioma, CNS WHO Grade 3

Simple Summary

Only 1% of all meningioma diagnosis is classified as malignant (anaplastic) meningioma. Due to their rarity, clinical management of these tumors presents several gaps. In this review, we investigate current knowledge of anaplastic meningioma focusing on their pathological and radiological diagnosis, molecular assessment, and loco-regional and systemic management. Despite the current marginal role of systemic therapy, it is possible that the increasing knowledge of molecular altered pathways of the disease will lead to the development of novel effective systemic treatments.

Abstract

Background: Meningiomas are the most common primary central nervous system malignancies accounting for 36% of all intracranial tumors. However, only 1% of meningioma is classified as malignant (anaplastic) meningioma. Due to their rarity, clinical management of these tumors presents several gaps. Methods: We carried out a narrative review aimed to investigate current knowledge of anaplastic meningioma focusing on their pathological and radiological diagnosis, molecular assessment, and loco-regional and systemic management. Results: The most frequent genetic alteration occurring in meningioma is the inactivation in the neurofibromatosis 2 genes (merlin). The accumulation of copy number losses, including 1p, 6p/q, 10q, 14q, and 18p/q, and less frequently 2p/q, 3p, 4p/q, 7p, 8p/q, and 9p, compatible with instability, is restricted to NF2 mutated meningioma. Surgery and different RT approaches represent the milestone of grade 3 meningioma management, while there is a marginal role of systemic therapy. Conclusions: Anaplastic meningiomas are rare tumors, and diagnosis should be suspected and confirmed by trained radiologists and pathologists. Despite the current marginal role of systemic therapy, it is possible that the increasing knowledge of molecular altered pathways of the disease will lead to the development of novel effective systemic treatments.

Long-Term Visual Function After Fractionated Stereotactic Radiotherapy for Primary Optic Nerve Sheath Meningioma: A Retrospective Analysis of 34 Subjects

Objective

To evaluate long-term visual function after fractionated stereotactic radiotherapy (FSRT) for primary optic nerve sheath meningioma (PONSM).

Methods

This 22-year retrospective study included 34 subjects (34 affected eyes) with PONSM who were treated with FSRT exclusively. Subjects with a history of biopsy/resection were excluded. Visual function, including visual acuity (VA) and visual field mean deviation (VF MD), was evaluated at presentation (pre-radiotherapy; pre-RT) and at the final follow-up (post-radiotherapy; post-RT); treatment complications were also evaluated. Treatment success was defined as either stabilization or improvement of visual function.

Results

The median pre-RT VA and pre-RT VF MD were 0.70 logarithm of the minimum angle of resolution (logMAR; range: 0.0–2.9 logMAR) and −15.4 decibels (dB) (range: −31.4 to −3.2 dB), respectively. The median total dose of FSRT was 50 Gy (range: 45–54 Gy) and the median number of fractions was 25 (range: 25–30). The median follow-up interval was 89 months (range: 6–251 months). The median post-RT VA and post-RT VF MD were 0.48 logMAR (range: 0.0–2.9 logMAR) (p = 0.010) and −6.8 dB (range: −20.6 to −1.6 dB) (p = 0.005), respectively. Among the 34 included eyes, VA was successfully treated in 29 eyes (85.3%) and worsened in 5 eyes (14.7%). Of the 14 eyes with both VA and reliable VF MD at pre-RT and post-RT time points, VF MD was successfully treated in 13 eyes (92.8%) and worsened in one (7.2%); overall visual function was successfully treated in 13 eyes (92.8%) and worsened in 1 eye (7.2%). Complications occurred in one subject (2.9%; radiation retinopathy).

Conclusion

Approximately 90% of PONSM subjects exhibited long-term treatment success in terms of VA, VF MD, and overall visual function after FSRT. Additionally, the incidence of complications was low. Therefore, FSRT is effective and safe treatment for PONSM.

Bilateral paediatric optic nerve sheath meningioma

At birth, the patient was noted to have microphthalmia and optic atrophy in her left eye with no apparent cause. In early childhood, the vision in that eye began to deteriorate. A few years later, disc swelling was noted in the contralateral right eye. Neuroimaging was normal and a subsequent lumbar puncture found borderline high opening pressure. Vision and visual fields in the right eye remained stable until the patient was in early adolescence when she started to complain of blurred vision. Her pattern visual evoked potential showed a 75% reduction in P100 amplitude compared with the previous year. Repeat neuroimaging was suggestive of bilateral meningiomas and a biopsy was performed to confirm this. Subsequently, the patient was treated with proton beam therapy to salvage vision in her right eye. This is a novel case of meningioma presenting with enophthalmos due to contraction of the retrobulbar optic nerve.

Radiotherapy and Radiosurgery in the Management of Optic Nerve Sheath Meningiomas: An International Systematic Review and Meta-Analysis of Twenty Studies

BACKGROUND

Optic nerve sheath meningiomas (ONMs) are often managed with radiotherapy (RT) with the goal of achieving radiographic local control (LC) and preventing deterioration of visual acuity (VA). We aimed to perform a systematic review and meta-analysis of outcomes for patients with ONM treated with RT.

METHODS

The PICOS/PRISMA/MOOSE selection criteria were used to identify studies. Primary outcomes were stable or improved VA and radiographic LC at last follow-up. The secondary outcomes were incidences of radiation-induced retinopathy and xerophthalmia and stable or improved visual fields (VFs). Weighted random-effects meta-analyses using the DerSimonian and Laird methods were conducted to characterize effect sizes. Mixed-effects regression models were used to examine potential correlations between gross tumor volume (GTV) and outcomes.

RESULTS

In total, 444 patients with ONM across 20 published studies were included. The estimated LC rate was 99.8% (95% confidence interval [CI], 98.3%-100%), and the estimated proportion of patients with stable or improved VA or VF was 89.7% (95% CI, 86.2%-92.4%) and 93.3% (95% CI, 89.5%-95.8%), respectively. Estimated incidences of radiation-induced retinopathy and xerophthalmia were 7.2% and 10.1%, respectively. GTV was significantly associated with VA (P = 0.014) with estimated VA rates of 96.4%, 91.4%, and 80.5% for GTVs of 2.0, 3.0, and 4.0 cm³, respectively.

CONCLUSIONS

RT was well tolerated, with excellent LC achieved. Nearly 90% of patients noted either stability or improvement in VA and VF. Larger ONMs were associated with poorer VA.

No Light Perception Vision in Neuro-Ophthalmology Practice

BACKGROUND

To determine differential diagnosis and visual outcomes of patients with no light perception (NLP) vision related to neuro-ophthalmic conditions.

METHODS

Retrospective case series of patients seen at tertiary neuro-ophthalmology practices. Patients were included if they had NLP vision any time during their clinical course. Outcome measures were final diagnosis, treatment, and visual outcome.

RESULTS

Seventy-two eyes of 65 patients were included. The average age was 57.6 (range 18-93) years, and 58% were women. The Most common diagnosis (21 patients) was compressive optic neuropathy (CON) with meningioma being the most common culprit (12). Other diagnoses included optic neuritis (ON) (11 patients), infiltrative optic neuropathies (8), posterior ischemic optic neuropathy (7), nonarteritic anterior ischemic optic neuropathy (4), arteritic anterior ischemic optic neuropathy (3), ophthalmic artery occlusion (3), nonorganic vision loss (3), radiation-induced optic neuropathy (2), cortical vision loss (1), retinitis pigmentosa with optic disc drusen (1), and infectious optic neuropathy (1). Ten patients recovered vision: 7 ON, 2 infiltrative optic neuropathy, and 1 CON. Corticosteroids accelerated vision recovery in 7 of the 11 patients with ON to mean 20/60 (0.48 logMAR) over 9.0 ± 8.6 follow-up months. Eleven patients deteriorated to NLP after presenting with at least LP; their diagnoses included CON (3), ophthalmic artery occlusion (2), infiltration (2), ON (1), posterior ischemic optic neuropathy (1), arteritic anterior ischemic optic neuropathy (1), and radiation-induced optic neuropathy (1).

CONCLUSIONS

NLP vision may occur because of various diagnoses. Vision recovery was mainly seen in patients with ON. Serious systemic conditions may present or relapse with NLP vision, which clinicians should consider as an alarming sign in patients with known malignancies.

Orbital indications

GKNS for uveal melanoma has become a recognized valued treatment which avoids enucleation of the eye. In the early days, the eccentric location of these tumors made treatment difficult, but Gamma Knife Perfexion has solved that problem. It is known that larger tumors and tumors with an anterior location have a worse prognosis. GKNS has also been of rather unexpected benefit in optic nerve gliomas that require treatment. Choroidal hemangiomas may benefit from treatment as can secondary glaucoma. It has also been found to be beneficial in the treatment of thyrotoxic ophthalmopathy.

[Results of radiation therapy for optic nerve sheath meningioma]

Optic nerve sheath meningioma (ONSM) is a slow-growing benign tumor that tends to extend intracranially. The tumor is characterized by vision disturbance, optic nerve atrophy and edema. At present, radiotherapy is recommended as the treatment of choice for ONSM.

PURPOSE

To assess the neuro-ophthalmic symptomatology of ONSM and how it changes in response to radiotherapy.

MATERIAL AND METHODS

In the period from 2004 to 2018, 112 patients with ONSM aged 17 to 76 years underwent stereotactic radiotherapy. In 91 patients, visual functions varied from light perception to 1.0; in 21 patients the affected eye was blind. The prospective follow-up of 103 patients lasted 6 months to 10 years (mean follow-up duration was 57 months). Studied patients underwent either conventional fractionated radiotherapy with Novalis (n=88) or hypofractionation radiotherapy with CyberKnife (n=24).

RESULTS

According to ophthalmological examination, in 60.5% of cases an improvement of visual functions was observed, 39.5% of patients had visual functions remain stable at the initial level. No vision impairment during irradiation was detected. Vision deterioration in the long-term follow-up was observed in 2 patients: extended tumor growth in one case and radio-induced retinopathy in the other.

CONCLUSION

The study showed that this method of treatment for ONSM is effective and safe, allowing preservation of visual functions and in some cases - its improvement, while tumor growth remains under control.

Radiotherapy for the treatment of optic nerve sheath meningioma: A systematic review and meta-analysis

OBJECTIVES

The management of Optic Nerve Sheath Meningiomas (ONSM) has suffered a significant shift due to new radiation techniques. However, there is no conclusive information on which approach presents better results in the literature. This meta-analysis aims to evaluate the outcomes of different radiotherapy (RT) modalities in the management of ONSM.

METHODS

A systematic review based on an electronic search was performed in MEDLINE, EMBASE, Cochrane, and Lilacs databases. Eligible studies included patients with ONSM treated with RT. Two reviewers independently assessed the eligibility of potential studies, extracted data, and performed the meta-analysis. Outcomes of interest were tumor control, visual acuity (VA), visual field, and complications.

RESULTS

Thirty-nine non-comparative studies involving 736 eyes with ONSM treated with RT were included. Six different techniques were studied: 2-dimensional RT (2DRT), 3D-conformal RT (3CRT), Stereotactic Fractionation RT (SFRT), stereotactic radiosurgery (SRS), intensity-modulated RT (IMRT), and proton beam therapy (PBT). With a mean follow-up period of 46 months, tumor control was 97,4% (95% CI: 98-100%). No difference was observed regarding the rate of final VA post-treatment among the modalities. The 3CRT showed substantially higher rates of complication than other techniques.

CONCLUSIONS

RT produces remarkable tumor control. New radiation modalities such as SFRT, IMRT, SRS, and PBT resulted in better therapeutic results with fewer complications than 2DRT and 3CRT. Thus, they should be the preferential choices for treating ONSM regardless of initial clinical presentation.

Efficacy and Safety of Proton Beam Therapy for Primary Optic Nerve Sheath Meningioma

Purpose

Management of optic nerve sheath meningiomas (ONSM) remains challenging. Photon radiation therapy (PhRT) is the most common treatment for sight-threatening ONSM. Proton beam therapy (PBT) is less commonly used because it is more expensive and because there are questions about its efficacy specifically in relation to ONSM. PBT has the theoretical advantage of reducing radiation exposure to adjacent structures. We report the visual outcome of patients with primary ONSM managed at the Fondation Ophtalmologique Adolphe de Rothschild, Paris, France, and treated with PBT at the Centre de Protonthérapie, Institut Curie, Orsay, France.

Methods

We conducted a retrospective review of all patients with primary ONSM who received PBT (either by itself or following surgery) between January 2006 and January 2019. Neuro-ophthalmic examinations were performed at presentation and after radiotherapy, and, when applicable, after surgery. Meningiomas were measured at the time of diagnosis and at each follow-up MRI examination.

Results

Sixty patients (50 women, 10 men; mean age, 45.2±11.1y) were included, of whom 29 underwent surgery. At presentation, 52 (87%) of them had decreased vision (average visual acuity: 0.6 logMAR). Fundus examination showed optic disc swelling (n=27; 46.5%), optic disc pallor (n=22; 37.9%), optic disc cupping (n=2; 3.4%), opto-ciliary shunt (n=8; 13.8%), or choroidal folds (n=5; 8.6%). Otherwise, it was unremarkable (n=7; 12.1%). After treatment, visual function was stable overall. Fundus examination showed pallor (n=47; 83.9%), swelling (n=3; 5.4%), or cupping (n=2; 3.4%) of the optic disc, or was unremarkable (n=5; 8.9%). The visual field of 8 patients worsened, while 3 developed asymptomatic retinal hemorrhages. Tumor shrunk significantly in 8 patients at 1 year after PBT and remained stable in size in all others. Patients with opto-ciliary shunts had significantly worse visual outcome than other patients. Retinal abnormalities were observed in 11 patients during follow-up.

Conclusion

PBT alone or in association with surgery appears to be a safe and efficient treatment for ONSM, reducing the tumor size and stabilizing visual function. The risk of developing radiation retinopathy seems to be higher when patients had upfront surgery.

Comparison of multiple tractography methods for reconstruction of the retinogeniculate visual pathway using diffusion MRI

The retinogeniculate visual pathway (RGVP) conveys visual information from the retina to the lateral geniculate nucleus. The RGVP has four subdivisions, including two decussating and two nondecussating pathways that cannot be identified on conventional structural magnetic resonance imaging (MRI). Diffusion MRI tractography has the potential to trace these subdivisions and is increasingly used to study the RGVP. However, it is not yet known which fiber tracking strategy is most suitable for RGVP reconstruction. In this study, four tractography methods are compared, including constrained spherical deconvolution (CSD) based probabilistic (iFOD1) and deterministic (SD-Stream) methods, and multi-fiber (UKF-2T) and single-fiber (UKF-1T) unscented Kalman filter (UKF) methods. Experiments use diffusion MRI data from 57 subjects in the Human Connectome Project. The RGVP is identified using regions of interest created by two clinical experts. Quantitative anatomical measurements and expert anatomical judgment are used to assess the advantages and limitations of the four tractography methods. Overall, we conclude that UKF-2T and iFOD1 produce the best RGVP reconstruction results. The iFOD1 method can better quantitatively estimate the percentage of decussating fibers, while the UKF-2T method produces reconstructed RGVPs that are judged to better correspond to the known anatomy and have the highest spatial overlap across subjects. Overall, we find that it is challenging for current tractography methods to both accurately track RGVP fibers that correspond to known anatomy and produce an approximately correct percentage of decussating fibers. We suggest that future algorithm development for RGVP tractography should take consideration of both of these two points.

Ectopic intraconal orbital meningioma - A rare case report

Background

Ectopic orbital meningiomas (OM) are a rare subset of OMs which are neither attached to the optic nerve sheath nor to the surrounding bone.

Case Description

We report the case of a 65-year-old female who presented with a 1 year history of proptosis followed by visual loss and restricted right eye movements since 3 months. Radiology of the orbits was suggestive of intraorbital, intraconal, and heterogeneous contrast enhancing right eye lesion which was completely excised through supraorbital orbitotomy approach. Intraoperatively, the right optic nerve, though compressed, and displaced inferiorly, was free from the lesion. The final histopathological diagnosis was "Meningioma WHO Grade I." At 3 months follow-up, patient's vision in the right eye improved from perception of light positive to 6/12 and there was no evidence of recurrence.

Conclusion

Rarity of ectopic OM, total surgical excision with an excellent postoperative visual outcome prompted us to report this case.

Rare Diseases of the Orbit

This article provides an overview of rare orbital diseases. Congenital malformations, inflammatory diseases, benign and malignant neoplasias are described. Although it represents a relatively small area of the body the orbit contains multiple different tissues. Therefore, a great variety of diseases can be found within the orbital space. That is the reason, why both the completeness and the level of detail in the description of particular diseases must be somewhat limited. Nevertheless, clinical manifestations, important aspects of diagnosis, treatment strategies, and, when specific data are available, the prognosis are described. The authors tried to highlight the most characteristic aspects of the different diseases to describe their relevant aspects in spite of the brevity of the subsections.

Approach to patient with unilateral optic disc edema and normal visual function

In patients with swollen optic nerve head and normal visual function, optic disc drusen (ODD) is the most common diagnosis. The best tests for detecting ODD are funds autofluorescence and enhanced-depth imaging ocular coherence tomography (EDIOCT). After ODD has been ruled out, asymmetric papilledema should be assumed to be the cause and MRI of the brain and orbits with contrast and venography should be performed in all patients. It allows one to look for indirect signs of increased inctracranial pressure (ICP), optic perineuritis, and other inflammatory or compressive processes affecting optic nerve or its sheath such as optic nerve sheath meningioma. If imaging signs of raised ICP are present, lumbar puncture should be performed with measurement of opening pressure and analysis of cerebrospinal fluid (CSF) contents in all patients with fever, meningismus or neurologic deficits as well as patients who are not in the typical demographic group for idiopathic intracranial hypertension (IIH). Optic nerve sheath enhancement on MRI should prompt work-up for causes of optic perineuritis. When the appropriate neuroimaging is normal, the differential diagnosis is limited and ophthalmological consultation is necessary to determine whether other subtle ocular abnormalities are present on biomicroscopic and dilated fundus examination.

Case report 68Ga-DOTATATE of optic nerve sheath meningioma

We report a patient with an optic nerve sheath meningioma whose diagnosis and management were guided by using Gallium-68 DOTA-Tyr³-octreotatate (⁶⁸Ga-DOTATATE).

Positron Emission Tomography-Computed Tomography (PET-CT).

Primary and Secondary Optic Nerve Sheath Meningioma

Objective  This study was aimed to review issues relating to the recognition, radiographic diagnosis, monitoring, and management of primary and secondary optic nerve sheath meningioma (ONSM). Design  This study is a review of peer-reviewed literature combined with illustrative case studies. Participants and Methods  A literature search was conducted via the PubMed database using pertinent search terms. Selected articles were limited to those written or translated into English. Additional works cited within articles were also included. Individual cases were drawn from the experience of a tertiary academic neuroophthalmic and orbital practice. Tables summarize radiotherapeutic and surgical studies, excluding single case reports and studies focusing on meningioma of intracranial origin. Main Outcome Measurements  Review of reported surgical and radiotherapeutic series is the primary measurement. Results  The natural history of optic nerve sheath meningiomas is primarily characterized by progressive ipsilateral vision loss. Diagnosis is typically based on radiographic imaging findings, with biopsy remaining indicated in some patients. Management strategies may include observation, radiation, and/or surgical intervention, or a combination of these approaches. The role of surgery, especially with respect to primary ONSM (pONSM), remains controversial. Advancement of radiotherapy techniques has shifted modern treatment paradigms in pONSM toward radiation as primary treatment, as surgical outcomes are inferior in major studies. Although radiation remains the treatment of choice in many cases, selected patients may benefit from surgery, especially in the setting of secondary ONSM (sONSM). Conclusion  A wide variety of radiotherapeutic and surgical treatment modalities for ONSM exist. The specific indications for each management strategy continue to be redefined.

Orbital Surgery: Evolution and Revolution

This article traces the development of orbital surgery and its subsequent modifications. It also points out the importance of defining one's goal before embarking on orbital surgery. Although generally considered part of ophthalmology, surgery on the orbit has been relatively neglected and not routinely practiced. This article reviews the history of development of orbital surgery, both the revolutionary ideas and the evolutionary changes. There are multiple orbital lesions that do not need to be treated with surgery at all. These days chemotherapy, radation therapy, or even immunotherapy may be more appropriate. The most common orbital pathology, that is thyroid orbitopathy, the physician needs to decide whether or not the orbit needs to be decompressed or whether there are problems related to motility that can be dealt with by eye muscle surgery.

Prognostic Factors for Functional Outcome of Patients with Optic Nerve Sheath Meningiomas Treated with Stereotactic Radiotherapy-Evaluation of Own and Meta-Analysis of Published Data

Simple Summary

This article highlights the fractionated stereotactic radiotherapy in the treatment of optic nerve sheath meningioma (ONSM). ONSM, a slow-growing tumor next to the optic nerve, causes over a long period partial or complete blindness. As visual impairments appear and progress slowly in the disease history, the need for treatment and treatment starting time are controversial. We restate in our article that fractionated stereotactic radiotherapy improves visual function. We further search for prognostic factors which might provide valuable additional and independent information on when to start treatment. We reveal that the visual acuity is a prognostic factor for the outcome of stereotactic therapy for ONSM and promote it as a biomarker for the decision for treatment initiation.

Abstract

Objective: To evaluate prognostic factors for a favorable outcome (improvement of the visual acuity or visual fields) after fractionated stereotactic radiotherapy (fSRT) of optic nerve sheath meningioma (ONSM). Methods: We performed a database search for ONSM treatments during the period from April 2008 to September 2019 in the prospective database for stereotactic radiosurgery/radiotherapy (SRS/SRT) of the Robert Janker Clinic Bonn (Department of Radiotherapy) and performed a literature review and meta-analysis of published data on ONSM between 2010 and 2019. Ophthalmic status before and after treatment was evaluated and the collective was dichotomized into two groups: functional improvement (FI; improvement of either visual acuity or visual fields) and non functional improvement (NFI; with stable or deteriorating visual acuity or visual fields). The two groups were compared regarding different variables: pretreatment visual acuity, age, gender, gross tumor volume (GTV), follow up (FU) time, tumor localization, and maximal retina dose. Results: Overall, 13 stereotactic radiotherapies were performed for ONSM (12 × fSRT, 1 × SRS). Mean follow up was 3 years (range: 1–5 years). The total dose was 50.4 Gy (5 × 1.8 Gy/week) in 12 patients treated with fSRT and 1 × 14 Gy in one SRS case. Mean GTV was 1.13 ccm (range: 0.44–2.20 ccm). During follow up, all tumors were stable or showed shrinkage of tumor volume (100% tumor control), no adverse events were observed, 53% of the patients achieved either better visual acuity or visual fields. Pretreatment visual acuity was significantly different between the FI and the NFI group (0.17 vs. 0.63, p = 0.03) in our series and in the meta analysis (p < 0.01). Moreover, shorter FU time and lower retinal dose were significantly linked (p < 0.05 and p < 0.01, respectively) with a better outcome in the meta-analysis but not in our patient cohort. Intracranial tumor localization, gender, and age were not significantly different between the two outcome groups. Conclusion: FSRT for ONSM achieves in over 50% of cases an improvement of the ophthalmic status with low morbidity and excellent tumor control in our series and the meta analysis. Patients with a favorable outcome had in all analysis a significantly higher visual acuity before treatment start. Therefore, we advocate using fSRT as early as possible before vision deterioration occurs.

Atypical acute presentation of an optic nerve sheath meningioma

PURPOSE

Primary optic nerve sheath meningiomas (ONSM) are benign lesions that typically present with findings of painless proptosis (59%), optic nerve pallor (55%), and decreased peripheral vision (35%). Herein we share an atypical case of a patient who presented acutely with periorbital pain and optic nerve head edema, and was ultimately determined to have a low-grade optic nerve meningioma.

OBSERVATIONS

A 36-year-old healthy woman presented with acute onset of left periorbital discomfort. She was found to have intact visual acuity, full peripheral vision, and ipsilateral optic nerve edema. MRI imaging revealed a large intraconal mass partially encircling the left optic nerve. Incisional biopsy revealed a diagnosis of meningioma, WHO grade 1.

CONCLUSIONS

Low-grade optic nerve sheath meningiomas may uncommonly present with acute pain and optic nerve head swelling, and absence of classic disease features.

Optic nerve sheath meningioma

PURPOSE OF REVIEW

Optic nerve sheath meningiomas (ONSMs) are rare benign tumors of the anterior visual pathway which present with slowly progressive and painless vision loss and account for approximately 2% of all orbital tumors. This article provides an overview as well as an update on the ONSMs with regards to cause, epidemiology, clinical presentation, diagnosis, and management in adults and pediatric population.

RECENT FINDINGS

The clinical presentation and prognosis of ONSMs can vary and largely depend on the location of tumor as well as the histologic type. Overall, the diagnosis is based on clinical presentation, examination, and neuroimaging findings. Nevertheless, delays in diagnosis or misdiagnosis are not uncommon and can result in higher morbidity rates. Recent advances in diagnostic as well as more effective and less-invasive treatment options are discussed in this review.

SUMMARY

ONSMs are a rare cause of slowly progressive and inexorable visual loss. Although ONSM diagnosis depends on the characteristic clinical and radiologic findings, prompt diagnosis, and appropriate management is critical for favorable visual outcomes. Thus, current focus is optimizing diagnostic as well-treatment methods for patients with ONSMs.

Meningioma: A Review of Clinicopathological and Molecular Aspects

Meningiomas are the most the common primary brain tumors in adults, representing approximately a third of all intracranial neoplasms. They classically are found to be more common in females, with the exception of higher grades that have a predilection for males, and patients of older age. Meningiomas can also be seen as a spectrum of inherited syndromes such as neurofibromatosis 2 as well as ionizing radiation. In general, the 5-year survival for a WHO grade I meningioma exceeds 80%; however, survival is greatly reduced in anaplastic meningiomas. The standard of care for meningiomas in a surgically-accessible location is gross total resection. Radiation therapy is generally saved for atypical, anaplastic, recurrent, and surgically inaccessible benign meningiomas with a total dose of ~60 Gy. However, the method of radiation, regimen and timing is still evolving and is an area of active research with ongoing clinical trials. While there are currently no good adjuvant chemotherapeutic agents available, recent advances in the genomic and epigenomic landscape of meningiomas are being explored for potential targeted therapy.

Advances in multidisciplinary therapy for meningiomas

Surgery has long been established as the first-line treatment for the majority of symptomatic and enlarging meningiomas, and evidence for its success is derived from retrospective case series. Despite surgical resection, a subset of meningiomas display aggressive behavior with early recurrences that are difficult to treat. The decision to radically resect meningiomas and involved structures is balanced against the risk for neurological injury in patients. Radiation therapy has largely been used as a complementary and safe therapeutic strategy in meningiomas with evidence primarily stemming from retrospective, single-institution reports. Two of the first cooperative group studies (RTOG 0539 and EORTC 22042) evaluating the outcomes of adjuvant radiation therapy in higher-risk meningiomas have shown promising preliminary results. Historically, systemic therapy has resulted in disappointing results in meningiomas. However, several clinical trials are under way evaluating the efficacy of chemotherapies, such as trabectedin, and novel molecular agents targeting Smoothened, AKT1, and focal adhesion kinase in patients with recurrent meningiomas.

Long-term treatment outcomes of patients with primary optic nerve sheath meningioma treated with stereotactic radiotherapy

We analysed the long-term outcomes of patients with primary optic nerve sheath meningioma (ONSM) treated with stereotactic radiotherapy (SRT). 26 patients with primary ONSM were treated with SRT between 2004 and 2013 at a single institution. SRT was delivered with image guidance to a median dose of 50.4 Gy in 28 fractions. 4 patients had prior surgical debulking. At a median radiological follow-up of 68 months, the MRI based tumour control was 100%. Visual acuity improved in 10 (38.4%), remained stable in 10 (38.4%) and was reduced in 6 (23.1%) patients following treatment. Stable or improved vision post-treatment was seen in 92.3% of patients with good pre-treatment vision (best corrected visual acuity 6/18 or better), compared to only 61.5% of patients with poor pre-treatment vision (best corrected visual acuity 6/24 or worse). Overall, the treatment was well tolerated with no Grade 2 or greater acute toxicity. Minimal other ophthalmic complications were seen with only one patient developing late onset Grade 3 radiation retinopathy.

Prognostic factors in the surgical treatment of intracanalicular primary optic nerve sheath meningiomas

OBJECTIVE

Although meningiomas frequently involve the optic nerve, primary optic nerve sheath meningiomas (ONSMs) are rare, accounting for only 1% of all meningiomas. Given the high risk of vision loss with these tumors, surgical intervention is seldom considered, and radiation or observation is commonly applied. Here, the authors describe the visual outcomes for a series of patients who were treated with surgery aiming at maximal tumor resection and highlight their prognostic factors.

METHODS

The authors retrospectively analyzed the data for 8 patients with intracanalicular ONSMs who had been surgically treated by the senior author (O.A.) between 1998 and 2016. Meningiomas extending into the optic canal from the intracranial cavity (i.e., clinoid, sphenoid wing, tuberculum sellae, diaphragma sellae) were excluded. Diagnosis was based on ophthalmological, radiological, and intraoperative findings, which were confirmed by the typical histological findings. Preoperative, postoperative, and follow-up visual assessments were performed by neuro-ophthalmologists in all cases.

RESULTS

The patients included 7 females and 1 male. The mean age at diagnosis was 45.1 years (range 25.0-70.0 years). Mean duration of follow-up was 38.9 months (range 3.0-88.0 months). All patients reported visual complaints, and all had objective evidence of optic nerve dysfunction. Their evaluation included visual field, visual acuity, funduscopy, and retinal fiber thickness. Total resection was obtained in 4 cases. Comparing preoperative and postoperative visual function revealed that 4 patients had improvement at the last follow-up, 1 patient had stable vision, and 3 patients had decreased function but none had total vision loss. All patients with good preoperative visual acuity maintained this status following surgical treatment. There was no surgical mortality or infection. Operative complications included binocular diplopia in 4 patients, which remitted spontaneously.

CONCLUSIONS

Surgery can play a beneficial role in the primary treatment of ONSM, especially lesions located in the posterior third of the nerve. Total removal can be achieved with vision preservation or improvement, without major surgical complications, especially at early stages of the disease. Patients with good preoperative vision and CSF flow in the optic sheath have better chances of a favorable outcome than those with poor vision.

Meningioma Originating from the Hypoglossal Canal: Case Report and Review of Literature

BACKGROUND

Primary extracranial meningiomas are uncommon neoplasms. In particular, meningioma involving the hypoglossal canal is extremely rare, with only 4 cases reported in the literature so far. Given that each of these meningiomas originated in the juxtacondyle region with involvement of the hypoglossal canal, to the best of our knowledge, a meningioma that exists only within the hypoglossal canal has yet to be reported.

CASE DESCRIPTION

We present a case of primary extracranial meningioma arising solely from the hypoglossal canal. A 62-year-old woman presented with long-term difficulty in tongue movement. Her tongue was deviated to the right, and neurologic examination revealed fasciculation and muscle wasting on the right side of the tongue. Computed tomography revealed a calcification in the right hypoglossal canal. Magnetic resonance imaging further demonstrated a hypointense tumor on both T1-weighted and T2-weighted images, with contrast enhancement in the right condyle. Total tumor removal was performed via a transcondylar approach, and histopathologic examination confirmed the presence of a transitional meningioma. No recurrence was observed at 14 months of follow-up. The patient's tongue atrophy was slightly improved, and the deviation completely disappeared.

CONCLUSIONS

In this extremely rare case of hypoglossal canal meningioma, total tumor removal via a transcondylar approach resulted in the recovery of hypoglossal nerve function.

Differentiation Researches on the Meningioma Subtypes by Radiomics from Contrast-Enhanced Magnetic Resonance Imaging: A Preliminary Study

BACKGROUND

Meningioma subtypes are one of the most common key points to the treatment and prognosis of patients. The purpose of this study was to investigate the differential diagnostic value of radiomics features on meningioma.

METHODS

A total of 241 patients with meningioma who had undergone tumor resection were randomly selected including 80 with meningothelial meningioma, 80 with fibrous meningioma, and 81 with transitional meningioma. These meningiomas were divided into 4 groups including: meningothelial versus fibrous (group 1), fibrous versus transitional (group 2), meningothelial versus transitional (group 3), and meningothelial versus fibrous versus transitional (group 4). All patients were examined using the same magnetic resonance scanner (GE 3.0 T) and the preoperative contrast-enhanced T1-weighted images were available. Radiomics features from the contrast-enhanced T1-weighted images of 241 patients were evaluated by 2 experienced radiology specialists.

RESULTS

A total of 385 radiomics features were extracted from the images of each patient. Several preprocessing methods were applied on the radiomics dataset to reduce the redundancy and highlight differences between different meningioma before the Fisher discrimination analysis was adopted and leave one out cross validation methods were used for the model validation. The differentiation accuracies of the Fisher discriminant analysis model for groups 1, 2, 3, and 4 were 99.4%, 98.8%, 100% and 100%, respectively; leave one out cross validation method was achieved for group 1, 2, 3, and 4 with the accuracies of 91.3%, 95.0%, 100%, and 94.2%, respectively.

CONCLUSIONS

Radiomics features and the combined Fisher discriminant analysis could provide satisfactory performance in the preoperative differential diagnosis of meningioma subtypes and enable the potential ability for clinical application.

The Role of Endonasal Endoscopic Optic Nerve Decompression as the Initial Management of Primary Optic Nerve Sheath Meningiomas

Background  The management of optic nerve sheath meningiomas (ONSMs) remains controversial. Surgical decompression through traditional resective techniques has been associated with significant morbidity. While radiation therapy, the current modality of choice is not exempt of risks. Transnasal endoscopic optic nerve decompression (EOND) offers a direct route to the orbit, optic canal, and orbital apex, providing a minimally invasive alternative. Objective  The main objective of this article is to assess EOND as the initial management of symptomatic patients with primary ONSM. Methods  Patients with ONSMs without a history of radiotherapy who underwent EOND were retrospectively reviewed. Postoperative imaging, duration of follow-up, and visual outcomes at the last ophthalmology visit were assessed. Results  Four women (age range 25-63 years) with primary ONSMs that underwent EOND were identified. All patients displayed subjective and objective baseline signs of vision loss. Additionally, baseline proptosis, diplopia, optic nerve atrophy, and ocular pain were identified. In none of the cases, the optic nerve sheath was breached. Following EOND, all patients deferred treatment with adjuvant radiotherapy. At a mean postoperative follow-up of 14 months, all patients were clinically stable without evidence of disease progression on imaging or physical examination. At last ophthalmologic evaluation, three out of four showed objective improvements from baseline visual acuity and visual field (remaining patient had baseline optic nerve atrophy). Conclusion  These results suggest that EOND could be a viable initial treatment modality of selected primary ONSM cases. Further studies are warranted to determine long-term efficacy and its role in a stepwise progression of management, preceding radiotherapy.

Long-term efficacy of fractionated conformal radiotherapy for the management of primary optic nerve sheath meningioma

BACKGROUND/AIM

Fractionated conformal radiotherapy (FCRT) is now used to treat vision-threatening optic nerve sheath meningioma (ONSM), but long-term efficacy and safety data are lacking; the purpose of this study was to assess these key data.

METHODS

This is a retrospective chart review with prospective follow-up of adult patients treated with FCRT for primary ONSM at four academic medical centres between 1995 and 2007 with ≥10 years of follow-up after treatment.

RESULTS

16 patients were identified with a mean post-treatment follow-up of 14.6 years (range: 10.5-20.7 years). The mean age at symptom onset was 47.6 years (range: 36-60 years). FCRT was performed at a mean of 2.3 years after symptom onset (range: 0.2-14.0 years). At last follow-up, visual acuity had improved or stabilised in 14 of the 16 (88%) patients, and 11 (69%) had retained or achieved ≥20/40. The mean deviation on automated perimetry remained stable (-14.5 dB pretreatment vs -12.2 dB at last follow-up; p=0.68, n=10). Two (11%) patients had persistent pain, proptosis or diplopia, compared with six (38%) pretreatment (p=0.11). Two (13%) patients developed radiation retinopathy more than 6 months after completion of therapy, one (50%) of whom had worse visual acuity compared with pretreatment. No patient developed tumour involvement or radiation damage in the fellow eye.

CONCLUSION

FCRT stabilises or improves visual function in patients with primary ONSM and is associated with a low risk of significant ocular sequelae. This treatment should be considered instead of surgery in patients with primary ONSM who require intervention due to loss of visual sensory and/or ocular motor function.

A novel surgical approach for intraorbital optic nerve tumors

Although orbital tumors involving the optic nerve are rare, it is well-known that they are very likely to cause serious visual impairment in a patient. Unfortunately, at present, there are no effective interventions that can reliably preserve visual function while controlling tumor growth into intracranial spaces. To ensure visual function of the non-affected side, transection of the optic nerve together with the tumors involved is necessary in some cases. For this procedure large craniotomy and orbital unroofing are commonly utilized. As an alternative, we propose a novel surgical intervention for transection of the optic nerve having optic nerve tumors, which utilizes a lateral orbitotomy approach. To evaluate the invasiveness of different surgical approaches, we compared the days of hospitalization after surgery across patients who underwent the transcranial, lateral, and anterior approaches, respectively. We successfully removed 2 optic nerve tumors using the lateral approach, which required significantly shorter hospitalization than the transcranial approach. The transection of the optic nerve together with tumor removal by the lateral approach may be one of the novel surgical interventions for optic nerve tumors as this method is considerably less invasive than the transcranial removal method.

Optic nerve sheath meningiomas: prevalence, impact, and management strategies

Optic nerve sheath meningiomas are rare benign neoplasms of the meninges surrounding the optic nerve. They are a significant cause of morbidity. While the mortality rate is practically zero, these tumors can blind or disfigure patients. Given that the clinical course can be variable, and treatment has the capacity to cause morbidity itself, the management of these patients can be difficult. We review the literature to discuss the prevalence of optic nerve sheath meningiomas, the association with neurofibromatosis type 2, natural history, and management options and strategies.

The Use of 68Ga-DOTATATE PET/CT in the Non-invasive Diagnosis of Optic Nerve Sheath Meningioma: A Case Report

We hereby report the case of a patient with optic nerve sheath meningioma (ONSM), whose diagnosis and multidisciplinary management was guided by the use of Gallium-68 (⁶⁸Ga)-labeled dodecanetetraacetic acid-tyrosine-3-octreotate (DOTATATE) positron emission tomography (PET)/computed tomography (CT) scan. We briefly review the diagnosis and management of ONSM, and review the literature on the role and current status of nuclear imaging with somatostatin receptor ligands in the non-invasive diagnosis and management of meningiomas.

Visual Outcomes and Local Control After Fractionated Stereotactic Radiotherapy for Optic Nerve Sheath Meningioma

PURPOSE

To review the outcomes of patients with optic nerve sheath meningiomas (ONSM) treated with fractionated stereotactic radiotherapy.

METHODS

Patient characteristics, treatment, and outcomes were analyzed for all patients with primary and secondary ONSM treated from 2001 to 2012. Clinically significant visual acuity change was defined as a 2-line change on the Snellen eye chart from pre-fractionated stereotactic radiotherapy.

RESULTS

Forty-one patients were treated: 23 patients with primary ONSM and 18 patients with secondary ONSM. The median age at diagnosis was 56 years. The median visual follow up was 3.8 years and the median radiologic follow up was 4.4 years. At diagnosis, 36% had normal vision (20/20-20/40), 10% had mild impairment (<20/40-20/60), 20% had moderate visual impairment (<20/60-20/200), 27% had severe impairment (<20/200), and 7% had no light perception. Common acute side effects were headache (32%) and nausea (15%); 15% of patients required corticosteroids during stereotactic radiotherapy. Chronic toxicities included retinopathy (7%), pituitary dysfunction (13%), chronic ocular pain (5%), and cataracts (2%). Visual acuity was stable in 65%, improved in 27%, and decreased in 8% of patients. Visual fields were stable in 70%, improved in 21%, and reduced in 9%. Actuarial 5-year local control rates were 100% for primary ONSM and 88% for secondary ONSM. Actuarial 5-year visual preservation rates were 100% for primary ONSM and 86% for secondary ONSM.

CONCLUSIONS

Fractionated stereotactic radiotherapy for primary and secondary ONSM was well tolerated and provides excellent local control and visual preservation. Longer follow up is required to determine the risk of late ocular and pituitary sequelae.

Optic Nerve Sheath Meningioma: Preliminary Analysis of the Role of Radiation Therapy

Background

The purpose of this study was to evaluate the treatment outcome of our optic nerve sheath meningioma (ONSM) case series in terms of preventing tumor growth and preserving vision in ONSM patients.

Methods

Between July 2003 and March 2015, 1,398 patients with intracranial meningioma were diagnosed at Seoul National University Bundang Hospital. Among them, only 13 patients (0.93%) were diagnosed with ONSM and enrolled in the present study. Tumor volume changes of ONSM patients and their visual acuity were evaluated before and after treatments.

Results

The median follow-up time was 50 months (range, 12–133 months). Visual acuity was evaluated in 12 of 13 patients, and visual acuity was found to be preserved in 9 of 12 patients (75%). Tumor volume was reduced in all patients. The tumor control rate was 100% in the present study. The difference in tumor volume between pretreatment and last follow-up was statistically significant (p=0.015).

Conclusion

Intensity-modulated radiotherapy (IMRT) and gamma knife radiosurgery (GKS) could maintain visual acuity and stabilize tumor volume in ONSM patients, suggesting that IMRT and GKS may be effective therapies for ONSM. However, which treatment is the more effective modality must be confirmed by prospective studies and longer-term follow-up.

Update on the application of optic nerve sheath fenestration

BACKGROUND

With the ongoing development of surgical procedures and instruments, the safety of optic nerve sheath fenestration (ONSF) has been improved.

OBJECTIVE

Through the past three decades, progress has been made in preventing visual loss from chronic optic nerve swelling in idiopathic intracranial hypertension (IIH), secondary intracranial hypertension and local optic nerve diseases. We now review the updated application of ONSF in those diseases.

METHODS

The application of ONSF in papilledema due to IIH, secondary intracranial hypertension to cerebral venous sinus occlusion, Cryptococcal meningitis, and intracranial mass or tumors is reviewed. Additionally, the potential benefits of ONSF in local optic neuropathy from optic nerve sheath meningioma, optic nerve drusen, traumatic optic neuropathy and optic nerve/sheath biopsy are also described.

RESULTS

Although ONSF has little or no effect on intracranial pressure, it is a safe, relative easy and effective surgical procedure to prevent or reverse visual loss in IIH. When other treatment modalities fail to timely protect vision, ONSF can be useful in protecting visual function or delay visual loss in secondary intracranial hypertension.

CONCLUSION

We recommend that ONSF should be considered as a meaningful alternative or an adjunct therapy to reduce or delay the visual morbidity of these diseases, although the use of ONSF for some of them remains controversial.

Natural history of primary paediatric optic nerve sheath meningioma: case series and review

PURPOSE

To study the natural history, clinical and radiological characteristics of primary paediatric optic nerve sheath meningioma (PPONSM).

METHODS

Retrospective study of eight paediatric patients who were treated between 1994 and 2016 at the University Hospital Zurich, Switzerland and the Royal Adelaide Hospital, Australia. Clinical records and imaging studies were reviewed.

RESULTS

The mean age at presentation was 11 years (range: 6-17 years). There were six female patients and two male patients. 2/8 patients had associated neurofibromatosis type 2. Patients were followed up for 71-297 months (mean 156±70 months). 6/8 patients were observed through the course of their disease and 2/8 patients were treated with radiotherapy. 2/8 patients who were observed had minimal change in vision and did not experience tumour growth after long-term follow-up.

CONCLUSIONS

This is the largest PPONSM case series with long-term data on patients treated conservatively. We highlight that a small subset of these tumours are indolent and can be managed using observation alone.

Diagnosis and Treatment of Orbital Optic Nerve Sheath Meningioma

BACKGROUND

Primary and secondary optic nerve sheath meningiomas (ONSMs) are neoplasms that account for a large proportion of optic nerve and orbital tumors. The diagnosis is not always straightforward and is based on the appropriate clinical findings and neuroimaging. Biopsy or surgical intervention may occasionally be necessary but is associated with significant morbidity.

METHODS

Issues related to clinical signs and symptoms, diagnosis, natural history, and treatment strategies are reviewed based on a review of published literature.

RESULTS

Diagnosis is usually based on radiographic and clinical findings. Biopsies are not obtained in most cases, thus adding further to the bias of possible misdiagnosis in all reported case series that do not have the benefit of histopathologic confirmation. Natural history typically shows inexorable progression in most cases, although long periods of stability are occasionally reported. Treatment options include observation, radiation alone, surgery alone, and combined radiation and surgery. The optimum timing of interventional therapy and radiation are evolving.

CONCLUSIONS

After serial examination documents new decline in acuity and/or visual field, fractionated radiotherapy appears most likely to preserve visual function and is a valid treatment approach for primary orbital ONSM. Tumor enlargement, as determined by serial imaging, may also provide an indication to begin radiotherapy.

Diagnosis of optic nerve sheath meningioma during optic nerve sheath decompression

Optic nerve sheath meningioma (ONSM) is typically diagnosed based on clinical suspicion and imaging characteristics and is most often treated with radiation. Historically, biopsy, optic nerve sheath decompression, and debulking surgeries have been avoided for fear of optic nerve vascular disruption and tumor spread into the orbit. This is a case of a 48-year-old man who presented with unilateral optic disc edema, declining visual acuity, and a visual field defect. Despite an initial improvement with acetazolamide, his vision subsequently worsened. With an elevated lumbar puncture opening pressure and imaging showing right optic nerve sheath enhancement, the differential diagnosis included ONSM, perineuritis and idiopathic intracranial hypertension (IIH). Optic nerve sheath decompression (ONSD) with biopsy was performed, simultaneously decompressing the nerve and yielding a sample for pathologic analysis. A pathologic diagnosis of ONSM was made and treatment with radiation was subsequently initiated, but vision began to improve after the surgical decompression alone.

A rare case of bilateral optic nerve sheath meningioma

A 60-year-old female presented with gradual, painless, progressive diminution of vision, and progressive proptosis of left eye since 7 years. Ophthalmological examination revealed mild proptosis and total optic atrophy in the left eye. Magnetic resonance imaging (MRI) and computed tomography (CT) brain with orbit showed bilateral optic nerve sheath meningioma (ONSM) involving the intracranial, intracanalicular, intraorbital part of the optic nerve extending up to optic chiasma and left cavernous sinus.