Optic Nerve Sheath Fenestration Research Articles

Case report: Bilateral optic nerve sheath meningocele: clinical aspects

Optic nerve sheath meningocele is an enlargement of the sheath itself, consisting of a collection of cerebrospinal fluid along the perineural space. It should be considered primary if it is not associated with orbital–cerebral neoplasm or with cranio-orbital junction malformations. We report three cases of bilateral primary idiopathic optic nerve sheath meningocele, two of them with gradual vision loss. The first case presented a history of monocular blurred vision of the right eye and headache. It was initially treated with acetazolamide without any improvement, after which optic nerve sheath fenestration was required. The second case showed intermittent binocular diplopia with central 24-2 perimetry defects in the left eye. The third case was first presented as a subacute bilateral conjunctivitis with a suspected orbital pseudotumor. An incidental bilateral optic nerve sheath meningocele was found in the orbital imaging, being totally asymptomatic. In all the cases, orbital and cranial magnetic resonance with contrast and fat suppression was crucial in the diagnosis.

Secondary pseudotumor cerebri in the pediatric population: clinical features, treatment, and prognosis

Purpose: Pseudotumor cerebri syndrome (PTSC) is characterized by elevated intracranial pressure (ICP) without intracranial mass, hydrocephalus, or abnormalities in cerebrospinal fluid composition. In secondary PTSC (sPTSC), there is a reason that increases the CSF pressure. The aim of this study is to evaluate the diagnosis, treatment, and follow-up of pediatric patients diagnosed with secondary PTC.
 Materials and methods: This is a retrospective study conducted in a single-center tertiary pediatric hospital. We included patients aged 1-17 years who were diagnosed with sPTSC in a tertiary hospital between 2018 and 2023 and met the current diagnostic criteria for PTSC. We evaluated the complaints, etiology, ophthalmological evaluations, and treatment results of the cases.
 Results: Seventeen patients with a diagnosis of PTCS were included in the study. The mean age was 9.82(±4.6). Of the patients, 9(56.2%) were male and 8(43.7%) were female. The most common symptoms were headache in 10 patients(62.5%), nausea/vomiting in 6 patients(37.5%), and double vision in 5 patients(31.2%). All patients had papilledema and 7(43.7%) patients had sixth nerve palsy. Recurrence was observed in 3(16%) patients. Optic nerve fenestration was performed in three patients as a second-line treatment.
 Conclusion: In cases that do not respond to medical treatment, optic nerve sheath fenestration may be a good treatment option.
 Keywords: optic nerve, child, pseudotumor cerebri

Peripapillary shape changes on optical coherence tomography following optic nerve sheath fenestration

Peripapillary shape changes on optical coherence tomography following optic nerve sheath fenestration

Role of Optic Nerve Fenestration as an Effective Salvage Therapy in Cerebral Venous Thrombosis: A Case Report and Review of Literature

Background: Cerebral venous thrombosis (CVT) is an uncommon, unrecognized type of stroke mostly affecting young people. Although a headache is the most common clinical manifestation of CVT, neurological focal signs like diplopia and papilledema are also frequently reported in the patients with such a problem. Currently, specific treatment for CVT involves anticoagulation or thrombolytic therapy. Case Report: In this report, we described a 13-year-old female, who was referred to our clinic with a headache and progressive loss of vision due to increased intracranial pressure. Along with usual anticoagulant therapy, we performed the optic nerve sheath fenestration (ONSF) to improve her vision. The patient visual acuity was improved, and after 11 months’ follow-up, no complication was detected. Conclusion: The ONSF can be safe and beneficial in patients with CVT and who are in immediate danger of visual deterioration despite being treated by other means. [GMJ.2017;6(2):160-65]

Supracerebellar infratentorial resection of a torcular lesion causing fulminant intracranial hypertension: illustrative case.

Venous sinus stenosis has been implicated in intracranial hypertension and can lead to papilledema and blindness. The authors report the unique case of a cerebellar transtentorial lesion resulting in venous sinus stenosis in the torcula and bilateral transverse sinuses that underwent resection. A 5-year-old male presented with subacute vision loss and bilateral papilledema. Imaging demonstrated a lesion causing mass effect on the torcula/transverse sinuses and findings of increased intracranial pressure (ICP). A lumbar puncture confirmed elevated pressure, and the patient underwent bilateral optic nerve sheath fenestration. Cerebral angiography and venous manometry showed elevated venous sinus pressures suggestive of venous hypertension. The patient underwent a craniotomy and supracerebellar/infratentorial approach. A stalk emanating from the cerebellum through the tentorium was identified and divided. Postoperative magnetic resonance imaging showed decreased lesion size and improved sinus patency. Papilledema resolved and other findings of elevated ICP improved. Pathology was consistent with atrophic cerebellar cortex. Serial imaging over 6 months demonstrated progressive decrease in the lesion with concurrent improvements in sinus patency. Although uncommon, symptoms of intracranial hypertension in patients with venous sinus lesions should prompt additional workup ranging from dedicated venous imaging to assessments of ICP and venous manometry.

Optic nerve sheath fenestration for salvaging acutely threatened vision in Idiopathic Intracranial Hypertension - A two-year completed follow up

Objectives: To determine the efficacy and safety of Optic Nerve Sheath Fenestration (ONSF) for salvaging acutely threatened vision in patients of Idiopathic Intracranial Hypertension (IIH).
 Methods: This retrospective, interventional case series study was performed at Institute of Ophthalmology Mayo Hospital Lahore from September 2017 to September 2019. Nine patients diagnosed with Idiopathic Intracranial Hypertension as per Modified Dandy Criteria, underwent medial trans-conjunctival ONSF. Pre-operative and 1st day, 1st week, 1st month, 1st year, and 2nd year postoperative best-corrected logMAR visual acuities (BCVA) were recorded. Mean BCVA were calculated and compared using paired t-test. P-value <0.05 was taken as significant.
 Results: All nine patients were female with a mean age of 24 years. The average best-correctedpre-operative logMAR visual acuity (BCVA) in the better eye was 0.5 ± 0.28 and in the worse eye was 1.0 ± 0.57. After the worse eye ONSF, at 1st week mean BCVA in better eyes was 0.27 ± 0.32 (p-value=0.001), while it was 0.43 ± 0.63 (p-value=0.006) in the worse eyes. At 2nd year follow-up after optic nerve sheath fenestration mean BCVA in better eyes was 0.30 ± 0.30 (p-value=0.002) and in worse eyes was 0.44 ± 0.63 (p-value=0.007). Four patients (44.4%) had a subconjunctival hemorrhage, two patients (22.2%) had binocular diplopia, one patient (11.1%) pre-septal cellulitis, and one patient (11.1%) had no improvement in vision because of pre-operative secondary optic atrophy. All patients had unilateral fenestration and bilateral improvement, six patients (66.67%) reported improvement in headache and successful tapering of medical therapy.
 Conclusion: Optic nerve sheath fenestration is effective as well as a safe surgical procedure to salvage acutely threatened vision in patients of Idiopathic Intracranial Hypertension on maximal medical treatment.
 doi: https://doi.org/10.12669/pjms.39.6.6441
 How to cite this: Latif S, Rizwan A, Khan AA, Zahra S. Optic nerve sheath fenestration for salvaging acutely threatened vision in Idiopathic Intracranial Hypertension - A two-year completed follow up. Pak J Med Sci. 2023;39(6):---------. doi: https://doi.org/10.12669/pjms.39.6.6441
 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Commentary: Endoscopic Endonasal Optic Nerve Decompression in Idiopathic Intracranial Hypertension: When to Implement Optic Nerve Sheath Fenestration.

Commentary: Endoscopic Endonasal Optic Nerve Decompression in Idiopathic Intracranial Hypertension: When to Implement Optic Nerve Sheath Fenestration.

Idiopathic Intracranial Venous Hypertension: Toward a Better Understanding of Venous Stenosis and the Role of Stenting in Idiopathic Intracranial Hypertension.

Venous sinus stenosis, typically at the junction of the transverse and sigmoid sinus, is increasingly recognized as a contributor to the pathophysiology of idiopathic intracranial hypertension (IIH), whether it be the intrinsic type that does not reverse with normalization of intracranial pressure or the extrinsic type, which does. Efforts to treat the stenosis and reduce the associated transstenotic gradient through placement of a stent at the site of stenosis have been studied over the past 2 decades, primarily through retrospective studies, with variable emphasis on formal visual testing and direct assessment of poststent opening pressure. Most studies have presented evidence for utilization of stenting as an alternative to cerebrospinal fluid shunting or optic nerve sheath fenestration in patients with IIH who harbor the stenosis and are refractory to or intolerant of intracranial pressure-lowering medications, but an assessment of the current data is needed to better understand the role of stenting for this patient population. A search in PubMed was made for "IIH," "papilledema," and "venous stenting." Data pre and post stenting, including symptoms attributable to IIH, intracranial pressure, papilledema, retinal nerve fiber layer thickening on optical coherence tomography, and visual field assessment (mean deviation), were collected. Need for retreatment and complications were assessed among all studies. Studies using stenting for special circumstances, such as cerebrospinal leaks or for stenosis along anomalous vessels, were reviewed. In total, 49 studies (45 retrospective and 4 prospective) and 18 case reports (with 3 or less patients) were found and included in the analysis, for a total of 1,626 patients. In 250 patients in whom poststent intracranial pressure was measured, the mean value was 19.7 cm H 2 O, reduced from a mean of 33 cm H 2 O. Transient visual obscurations resolved in 79.6% of 201 patients who complained of it, pulsatile tinnitus resolved in 84.7% of 515, diplopia resolved in 93% of 86 patients, and nonspecific visual symptoms such as "blurry vision" improved in 76.2% of 537 patients. Headaches resolved in 36% and improved in a further 40.7% of 1,105 patients in whom they were documented before stenting. Of 1,116 with papilledema, 40.8% demonstrated resolution and 38.2% improvement. The mean retinal nerve fiber layer thickness improved from 170.2 µm to 89.2 µm among 402 eyes in which optical coherence tomography was used to measure it. Among 135 eyes in which formal visual fields were performed pre and post stenting, the prestent average mean deviation of -7.35 dB improved to -4.72 dB after stenting. Complications associated with stenting included in-stent stenosis or thrombosis, subdural hematoma, intracerebral hematoma, cerebral edema, stent migration, and death. A recurrence of symptoms requiring a follow-up surgical intervention occurred in 9%. A growing body of evidence supports the use of venous sinus stenting as a viable option for medically refractory IIH, especially when papilledema threatens visual function. Complication and failure rates seem to be similar to alternative surgical approaches, although serious neurological sequalae can rarely occur. Emerging studies evaluating stent type, including novel stents designed for use in the venous system, may help improve ease of the procedure and long-term success rates. Prospective head-to-head studies are needed to better understand the performance of stenting compared with other interventions.

Optic nerve sheath fenestration: A second lease at sight.

To study the safety and efficacy of optic nerve sheath fenestration surgery in patients with optic disc edema due to different etiologies. Records of 18 eyes of 15 patients who underwent optic nerve sheath fenestration for vision threatening optic disc edema were reviewed retrospectively, and results were analyzed. Improvement of visual acuity was the main measure of outcome. Improved visual fields, resolution of optic disc edema, diplopia, and headache were other benefits that were observed. Fifteen patients between 13 and 54 years of age were included in the study. Three patients underwent successive bilateral surgery. Idiopathic intracranial hypertension was the most common cause for optic disc edema and was found in 80% of the patients. Mean preoperative logMAR acuity was -1.9789 ± 1.46270, which improved to -0.9022 ± 1.23181 (p < 0.005) in the operated eye, and mean logMAR acuity of contralateral eye improved from -1.3378 ± 1.50107 to -1.0667 ± 1.33813 (p < 0.05). Early optic nerve sheath fenestration is an effective modality for treating optic disc edema due to a wide myriad of causes and helps resolve the associated symptoms.

Endoscopic Endonasal Optic Nerve Decompression in Idiopathic Intracranial Hypertension: When to Implement Optic Nerve Sheath Fenestration.

Idiopathic intracranial hypertension (IIH) is a syndrome characterized with increased intracranial pressure and normal cerebrospinal fluid (CSF) composition. Treatment is mainly conservative, whereas CSF diversion surgery is the most frequently used surgical intervention. Endoscopic endonasal optic nerve decompression (EOND) is a newer surgical treatment of this patient group. This study presents a single clinic's case series with comparative results of unilateral an bilateral EOND with or without optic nerve fenestration. Sixteen patients with IIH syndrome who underwent 18 EOND procedures by a single neurosurgeon were evaluated with MRI and digitally subtracted angiography preoperatively. Both preoperative and postoperative visual acuity and perimetry and fundoscopy examinations were routinely performed. All patients underwent sphenoidotomy using the endoscopic binostril approach; however, unilateral or bilateral optic nerve decompression and accompanying optic sheath fenestration was determined on a case-by-case basis, after which all patients were also evaluated for the outcome of headaches. Most of the patients were female, and the mean age was 30.28 ± 9.78 years. CSF pressure was increased in all patients (406.43 ± 112.91 mm of H 2 O), and the follow-up period was 61.72 ± 21.67 months. In patients with unilateral EOND, visual fields improved in 83%, visual acuity in 70%, headache in 75%, and papilledema in 27% of cases. In patients with bilateral EOND, perimetry improved in 86%, visual acuity in 43%, headache in 50%, and papilledema in 57% of cases. EOND is an effective surgical option in the treatment of IIH. Bilateral decompression is preferable in patients with bilateral visual involvement, and optic nerve fenestration may prove to be helpful in patients with IIH whose primary complaint is headache.

Endoscopic endonasal optic nerve sheath decompression (EONSD) for idiopathic intracranial hypertension: Technical details and meta-analysis

BackgroundThe neurosurgical management of idiopathic intracranial hypertension (IIH) remains controversial. Although shunting and newer endovascular stenting techniques are part of the neurosurgical armamentarium to treat medically refractory IIH symptoms, optic nerve sheath fenestration has traditionally been performed by ophthalmologists. ObjectiveWe present a detailed cadaveric dissection that simulates the endoscopic endonasal optic nerve sheath decompression (EONSD) technique along with the literature review. MethodsEONSD was performed in four freshly injected cadaveric specimens. Additionally, a systematic review from different electronic databases has been done. ResultsBilateral EONSD was performed in all specimens without significant technical difficulties. Based on our experience, there is no need to expose the periorbita or orbital apex. The primary anatomic landmarks were the optic canal, the lateral opticocarotid recess, the tuberculum, the limbus, and the clinoid segment of the internal carotid artery. Based on the systematic review, 68 patients (77.9% female) underwent EONSD, with a mean age of 33.4 ± 6.9 years in adult patients. Follow-up ranged from 3 to 58 months across different studies. The pooled meta-analysis showed headache, papilledema, and visual disturbance improvement in 78% [95%CI 0.65–0.90], 72% [95%CI 0.61–0.83], and 88% [95%CI 0.80–0.96] of cases who underwent EONSD, respectively. The subgroup analysis showed there was no statistically significant difference between unilateral and bilateral EONSD in terms of different measured outcomes. ConclusionEONSD is a feasible surgical procedure that may obviate the need for shunting in patients with IIH. Although clinical studies showed that EONSD is a safe and effective technique, further studies are required to establish the preferences of either unilateral or bilateral approaches.

Select Patients with High-Risk IIH May Be Managed with Medical Therapy Alone (P2-9.009)

<h3>Objective:</h3> Measure visual outcomes in high-risk idiopathic intracranial hypertension (IIH), with particular attention to medical or surgical treatment course and disease recurrence. <h3>Background:</h3> In IIH, presentations with BMI &gt;40, high-grade papilledema, worse visual field mean deviation (VFMD), and worse visual acuity are associated with worse visual outcomes. In the absence of randomized data on high-risk patients, surgery is often recommended, but risks complications, infections, or surgical revision. <h3>Design/Methods:</h3> We retrospectively reviewed the charts of all IIH patients who presented to 3 providers between April 2019 and April 2022 with grade IV or V papilledema. Patients were treated at the discretion of their neuro-ophthalmologist. Outcomes were stratified by presenting VFMD. <h3>Results:</h3> 11 patients were evaluated. Average age was 25.8 years, 10/11 were female, and average BMI was 38.3 kg/m2. On presentation, VA was 20/30 or worse in 9/11 patients, but improved to 20/20 or better in 9/11 patients. Average presenting VFMD was −13.8 dB, but improved by an average of 7.1 dB in those with initial VFMD worse than −7.0 dB and 2.1 dB in those with initial VFMD better than −7.0 dB. 2 patients met published criteria for “fulminant” IIH, but both improved to 20/20 acuity OU with significant VFMD improvements on medical therapy alone. All patients received acetazolamide with rapid dose escalation. Average maximum dose was 2.75 g per day. 2 also received topiramate. 1 patient received a ventriculoperitoneal shunt 3 days after presentation. 1 patient received an optic nerve sheath fenestration 15 days after presentation. 1 patient on medical therapy had recurrent disease over an average of 352 days of follow up. <h3>Conclusions:</h3> Select patients with high-risk or “fulminant” IIH may be successfully managed without surgery. These patients required close monitoring and aggressive medical therapy. Reduced visual acuity on presentation recovered well in most patients. Larger cohorts with longer follow-up are needed. <b>Disclosure:</b> Dr. Gluckstein has nothing to disclose. An immediate family member of Dr. Rizzo has received personal compensation for serving as an employee of LIfeBiosciences. Dr. Rizzo has received intellectual property interests from a discovery or technology relating to health care. Dr. Rizzo has received intellectual property interests from a discovery or technology relating to health care. Dr. Chen has nothing to disclose.

National Trends of Cerebral Venous Sinus Stenting for the Treatment of Idiopathic Intracranial Hypertension.

Cerebral venous sinus stenting (VSS) has emerged as a new surgical procedure for the treatment of severe idiopathic intracranial hypertension (IIH), and its popularity has been anecdotally on the rise. This study explores recent temporal trends of VSS and other surgical IIH treatments in the United States. Adult patients with IIH were identified from the 2016-2020 National Inpatient Sample databases, and surgical procedures and hospital characteristics were recorded. Temporal trends of procedure numbers for VSS, CSF shunts, and optic nerve sheath fenestrations (ONSFs) were assessed and compared. A total of 46,065 (95% CI 44,710-47,420) patients with IIH were identified, of whom 7,535 patients (95% CI 6,982-8,088) received surgical IIH treatments. VSS procedures increased 80% (150 [95% CI 55-245] to 270 [95% CI 162-378] per year, p < 0.001). Concurrently, the number of CSF shunts decreased by 19% (1,365 [95% CI 1,126-1,604] to 1,105 [95% CI 900-1,310] per year, p < 0.001), and ONSF procedures decreased by 54% (65 [95% CI 20-110] to 30 [95% CI 6-54] per year, p < 0.001). Practice patterns for surgical IIH treatment in the United States are rapidly evolving, and VSS is becoming increasingly common. These findings highlight the urgency of randomized controlled trials to investigate the comparative effectiveness and safety of VSS, CSF shunts, ONSF, and standard medical treatments.

Symptoms: Dizziness and Deafness

Symptoms: Dizziness and Deafness

Idiopathic Intracranial Hypertension in Female-to-Male Transgender Patients on Exogenous Testosterone Therapy.

To present four female-to-male (FTM) transgender patients on testosterone therapy diagnosed with idiopathic intracranial hypertension (IIH). The authors report 4 consecutive FTM transgender patients on exogenous testosterone diagnosed with IIH at a single institution. Patient 1 presented with progressive blurred vision and a central scotoma 10 weeks after starting testosterone cypionate injections for hormonal gender transition. Bilateral grade 5 papilledema was present; the patient underwent bilateral optic nerve sheath fenestration with improved vision and resolution of edema. Patient 2 presented with transient vision loss, pulsatile tinnitus, and blurred vision 13 months after starting testosterone cypionate injections. The patient had grade 4 and 3 disc edema of the right and left eyes, respectively. Patient 3 presented with headaches and pulsatile tinnitus and was on testosterone injections at an unknown dose. The examination revealed grade 1 and 2 disc edema of the right and left eyes, respectively. Patient 4 presented with decreased vision, transient visual obscurations, and daily migraines while using topical testosterone gel every other day. Color vision was reduced, and lumbar puncture revealed elevated intracranial pressure. All patients had neuroimaging findings consistent with increased intracranial pressure. Testosterone therapy plays an essential role in FTM hormonal transitioning and may play a role in IIH. Patients undergoing testosterone therapy for gender transition should be informed of the possibility of developing IIH while on treatment, with obesity possibly increasing this risk. Comprehensive eye examinations should be considered in these patients before initiating hormone therapy.

Optic nerve sheath fenestration for treating papilloedema in the era of cerebral venous sinus stenting.

Pseudotumour cerebri (PTC) is the syndrome of intracranial hypertension without intracranial mass or hydrocephalus and is the commonest cause of papilloedema seen in many eye clinics. In the last 10 years, we have increasingly used TSS in patients whose papilloedema was not well controlled with medical treatment and have done fewer ONSFs. Here, we review our experience at Royal Prince Alfred Hospital Sydney with ONSF in 35 patients over the period 2002-2021. Retrospective case series of 35 patients, 30 of whom had primary PTC [i.e., idiopathic intracranial hypertension (IIH)] and 5 with secondary PTC. Eighteen patients had bilateral ONSF and 17 patients unilateral ONSF, in each case of the worse eye. Thirteen patients then underwent transverse sinus stenting (TSS), in each case following ONSF. The primary outcome measures were visual acuity (VA) and mean deviation (MD) on visual field (VF) testing. MD improved by 5 dB or more in 34 of 70 total eyes (48.6%); VA improved by 0.2 logMAR (two lines on Snellen chart) or more in 21 eyes (30%), and by both in 15 eyes (21.4%). Final MD was -10 dB or better in 38 eyes (54.3%); final VA was 0.3 (6/12) or better in 54 eyes (77.1%), and both in 39 eyes (55.7%). The results confirm that ONSF can relieve papilloedoema in both eyes and improve both VF and VA, even in cases of fulminant PTC with severe acute visual impairment.

Efficacy of Optic Nerve Sheath Fenestration in Patients with Increased Intracranial Pressure.

To evaluate the effectiveness of optic nerve sheath fenestration (ONSF) on visual functions in patients with increased intracranial pressure (İİP). The medical records of 24 eyes of 17 patients who had İİP due to idiopathic intracranial hypertension, cerebral venous sinus thrombosis, or intracranial cyst and underwent ONSF surgery to prevent visual loss were evaluated. Pre- and postoperative visual acuity, optic disc images, and visual field findings were reviewed. The mean age of the patients was 30.4±8.5 years, and 88.2% were female. The patients' mean body mass index was 28.67±6.1 kg/m2. The mean follow-up time was 24±12.1 months (range: 3-44). At postoperative 3 months, the mean best-corrected distance visual acuity had improved in 20 eyes (83.3%) and stabilized in 4 eyes (16.7%) compared to preoperative values. In visual field mean deviation, an improvement was observed in 10 eyes (90.9%), while 1 eye (9.1%) eye remained stable. Optic disc edema decreased in all patients. This study indicates that ONSF has beneficial effects on visual function in patients with rapidly progressive visual loss caused by increased intracranial pressure.

Comparison of the therapeutic effects of optic nerve sheath fenestration and medication on papilledema due to cerebral venous thrombosis

Objective: To compare the therapeutic effects of optic nerve sheath fenestration (ONSF) and medication on papilledema induced by cerebral venous thrombosis (CVT). Methods: Patients with papilledema induced by CVT in Beijing Tiantan Hospital and Xuanwu Hospital from January 2017 to July 2022 were retrospectively enrolled and were divided into two groups according to the treatment strategies they underwent, with 76 cases (107 eyes) in ONSF group and 35 cases (69 eyes) in medication group. The degree of papilledema was evaluated by the modified Frisén's grading (grade 0-1 was defined as mild, grade 2-3 was moderate, and grade 4-5 was severe edema). The mean defect (MD) of visual field, the degree of papilledema, and the mean retinal nerve fiber layer (RNFL) thickness in different subgroups were compared between baseline versus 1 month after ONSF or medication. Results: There were 76 cases in ONSF group (26 males and 50 females), and aged (35.3±11.4) years. Meanwhile, there were 35 cases in medication group (22 males and 13 females), and aged (35.2±11.0) years. Compared with baseline, MD were improved in both moderate [(-8.4±6.6) vs (-11.8±8.6) db, P=0.021] and severe [(-8.1±5.3) vs (-11.4±6.9) db, P<0.001] papilledema subgroups after ONSF, while there was an improvement in mild papilledema subgroup [(-1.5±5.3) vs (-3.4±5.1) db, P<0.001] after medication. The papilledema (Frisén's scores) in both ONSF group (P<0.001) and medication group (P=0.010) was improved. Compared with baseline, the mean RNFL decreased in mild [(78.5±13.5) vs (91.0±17.4) μm, P=0.002], moderate [(126.6±67.6) vs (154.8±77.9) μm, P=0.011] and severe [(179.0±70.9) vs (230.6±89.7) μm, P=0.001] papilledema subgroups after ONSF, while the mean RNFL decreased [(142.0±29.3) vs (158.8±22.7) μm, P=0.020] in moderate papilledema subgroup after medication. Conclusions: ONSF might attenuate CVT-mediated papilledema, and improve the visual function in patients with moderate and severe papilledema. Likewise, patients with mild papilledema could also get benefit from medication.

Optic nerve sheath fenestration for visual impairment in cerebral venous diseases.

Visual impairment is the most common clinical feature of cerebral venous sinus occlusion or cerebral venous thrombosis-induced intracranial hypertension, which can result in optic atrophy, leading to irreversible vision loss, visual field defections, and finally, permanent blindness. Papilledema is a typical early pathophysiological alteration in visual impairment. Optic nerve sheath fenestration (ONSF) has become increasingly accepted as an option to prevent or halt progressive visual loss owing to its low risk and complications. The objective of this study is to review the latest research progress on ONSF for the treatment of visual impairment related to cerebral venous diseases. Study were searched following PRISMA guidelines based on three electronic databases (Pubmed, Embase and Medline-Ovid). We used the following keywords and variations as keywords to identify studies: "optic nerve sheath fenestration, papilledema, cerebral venous diseases, cerebral venous stenosis, cerebral venous thrombosis, idiopathic intracranial hypertension". The publication date of studies was restricted between 1,872.1.1 and 2,021.12.31. The application of ONSF in papilledema due to cerebral venous diseases is reviewed. Additionally, the common surgical approaches as well as advantages and disadvantages are also described graphically. With the improvement of specific details of the ONSF procedure and surgical instruments, complications of ONSF have reduced and its safety has been significantly improved, although the number of clinically investigated cases in the literature remains low. We recommend that ONSF should be considered as an imperative alternative to reduce or delay the visual morbidity of cerebral venous diseases, although there is yet no consensus on the optimal surgical timing.

Optic Nerve Sheath Fenestration for Progressive Visual Loss in Cerebral Venous Sinus Thrombosis: A Long-Term Retrospective Observational Study.

Progressive cerebral venous sinus thrombosis (CVST)-induced visual loss remains problematic, despite decreasing overall mortality owing to early diagnosis and aggressive treatment. Optic nerve sheath fenestration (ONSF) improves or stabilizes visual function in patients with idiopathic intracranial hypertension; however, its role in CVST awaits elucidation. We evaluated the efficacy and safety of ONSF in resolving CVST-induced visual impairment based on long-term observation. This observational study included 18 patients with progressive CVST-induced visual loss, who had undergone ONSF between 2012 and 2021. Patients received maximum medical therapy, including anticoagulants and intracranial pressure (ICP)-lowering medications. The best-corrected visual acuity (BCVA), visual fields (VFs), and optic nerve head were assessed at baseline, at 1week after ONSF, and over 6months after ONSF. Activities of daily living (ADL) and National Eye Institute Visual Function Questionnaire-25 (VFQ-25) scores were assessed at final follow-up. Thirty-one ONSF-treated eyes of 18 patients were included. The mean follow-up duration was 35.6months (range 1week-8years). Two patients were lost to follow-up. Before ONSF, all patients were still experiencing progressive visual loss despite receiving adequate anticoagulation and ICP-lowering therapy. Postoperative BCVA remained stable or improved in 25/31 eyes (80.6%) 1week postoperatively and 17/28 eyes (60.7%) upon final follow-up. All papilledema resolved postoperatively. No complications were reported except for one transient postoperative diplopia. The median ADL score was 100 (range 25-100), and the mean total VFQ-25 score was 40.6 (range 9.5-87.3). This was the largest study to describe ONSF's role in CVST based on a long-term follow-up. Considering its efficacy and favorable safety, ONSF can be considered an important adjunctive approach to resolving progressive visual loss of CVST patients, on the basis of anticoagulation and ICP-lowering therapy.