Papilledema: the vexing issues

Optic nerve sheath diameter and eyeball transverse diameter in severe head injury and its correlation with intracranial pressure

BACKGROUND

Gold standard for determining intracranial pressure (ICP), intraventricular catheter, is invasive with associated risks. Non-invasive investigations like magnetic resonance imaging and ultrasonography have demonstrated correlation between optic nerve sheath diameter (ONSD) and raised ICP. However, computed tomography (CT) is accessible and less operator-dependent. Literature shows variable results regarding correlations between ICP and ONSD on CT. The study aimed to investigate correlations between raised ICP and ONSD, eyeball transverse diameter (ETD), and ONSD/ETD ratios on CT scan(s) of severe head injuries.

METHODS

A retrospective review of a three-year prospectively-maintained database of severe traumatic head injuries in patients who had ICP measurements and CT scans was conducted. Glasgow Coma Score (GCS), ICP, ONSD 3 mm and 9 mm behind the globe, ETD, ONSD/ETD ratios, CT Marshall Grade, and Glasgow Outcome Score (GOS) were recorded. Statistical analysis assessed correlations between ICP and CT measurements.

RESULTS

Seventy-four patients were assessed; mortality rate: 36.5 %. Assault (48.6 %) and pedestrian-vehicle collisions (21.6 %) were the most common mechanisms. CT Marshall Grade correlated significantly with 3 mm and 9 mm ONSD, ONSD/ETD ratios, GCS, and GCS motor score, which correlated significantly with GOS. No significant correlation was found between ICP and ONSD, ETD or ONSD/ETD ratios. Marshall Grade was not significantly associated with ICP measurements but correlated with injury severity.

CONCLUSIONS

Unlike previous studies, our study not only investigated the correlation between ICP and single variables (ONSD and ETD) but also the ONSD/ETD ratios. No correlations were observed between raised ICP and ONSD, ETD or ONSD/ETD ratio on CT in neurotrauma patients.

Which OCT Measure of the Optic Nerve Head Improves Fastest? Towards Optimizing Early Detection of Resolving Papilledema in Children

Purpose

Optical coherence tomography (OCT) has been used to monitor papilledema. This study aims to determine which OCT-derived measures of the optic nerve head (ONH) detect resolving papilledema in children faster than standard OCT measures.

Methods

Children (≤18 years of age) with papilledema who completed optic nerve SD-OCT pretreatment and had evidence of treatment response on one or more follow-up OCTs within 4 months were included. Standard (mean circumpapillary retinal nerve fiber layer [cpRNFL] thickness), device-derived (per-quadrant cpRNFL) and custom (ONH height, maximum Bruch's membrane displacement [BMD], ONH volume [ONHV], and BMD volume) OCT measures were calculated. Per-eye generalized estimating equations (GEEs) modelled changes in device-derived and custom measures as a function of mean cpRNFL to identify those measures that resolved faster during early (0-2 months) follow-up. Mean cpRNFL coefficients of greater than 1 indicated faster resolving papilledema.

Results

We included 52 eyes of 29 children (mean age, 12.8 years; 72.4% female). In analysis of early follow-up visits (38 eyes from 22 children), nasal cpRNFL and maximum BMD in each quadrant resolved faster than mean cpRNFL (GEE coefficients range, 1.14-3.37). Inferior cpRNFL, superior, nasal, and inferior ONH heights and ONHV resolved slower than mean cpRNFL (GEE coefficients range, 0.67-0.87).

Conclusions

Nasal cpRNFL is a promising device-derived OCT measure for the early detection of resolving papilledema in children compared with mean cpRNFL. Maximum BMD, a custom measure, also shows promise, but its calculation has not yet been incorporated into commercial OCT devices.

Translational Relevance

This study guides the optimal use of OCT in capturing resolving papilledema in children.

Secondary Intracranial Hypertension in Pediatric Lyme Meningitis

Lyme disease is the most common vector-borne disease in the United States and has been associated with secondary intracranial hypertension. We reviewed 11 pediatric patients with Lyme-associated secondary intracranial hypertension. All patients presented with headache, ten had papilledema, 7 with a rash, and 5 with a cranial nerve palsy. All patients were treated with acetazolamide, and 3 received combination therapy with furosemide. Three patients were considered to have fulminant intracranial hypertension because of the severity in their presenting courses. Two of the fulminant intracranial hypertension patients were treated with a temporary lumbar drain in addition to medications, whereas 1 fulminant intracranial hypertension patient was treated exclusively with medical therapy alone. The addition of a lumbar drain decreased the time to resolution of papilledema compared to medical management alone. Final visual acuity was 20/20 in each eye of all patients, suggesting that a titrated approach to therapy depending on the severity of presentation can result in good visual outcomes in these cases. Additionally, symptoms can recur after medication wean, so patients should be monitored closely with any discontinuation of intracranial pressure lowering medications.

Transverse Sinus Stenting Reverses Medically Refractory Idiopathic Intracranial Hypertension

Aim

To characterise the ophthalmic indications for, and ophthalmic efficacy of, transverse sinus stenting in adults with medically refractory idiopathic intracranial hypertension.

Methods

A retrospective cohort study was undertaken on a single-author database of 226 successive patients with confirmed idiopathic intracranial hypertension (IIH). A total of 32 patients were identified who received a transverse sinus stent for medically refractory disease. This which was defined as visual threat and/or intolerance of maximal medical therapy. Patients with medically refractory disease proceeded to stenting, if found to have a significant transverse sinus stenosis gradient at catheter venography. Visual threat was quantified via the degree of papilledema on optical coherence tomography of the retinal nerve fibre layer, and via the visual field mean deviation. CSF opening pressure at lumbar puncture and cerebral venous sinus pressure measurements from catheter venography were correlated with the ophthalmic data, noting also intolerance of maximal medical therapy. Complications of stenting were fully assessed.

Results

Medically refractory IIH was found in 18% of the total cohort of IIH patients. 90% of those with medically refractory disease had a significant transverse sinus stenosis pressure gradient, and 80% proceeded to stenting. The intervention eliminated papilledema in 96% of stented patients, and allowed 81% to cease acetazolamide. The need for a further procedure was low at 6%, and the safety profile was favourable.

Conclusions

Medically refractory disease in IIH is common (18%), and nearly always associated with a significant transverse sinus stenosis pressure gradient (90%). Endovascular stenting of the stenosis deserves wider uptake as a highly effective, safe, and usually definitive treatment. It safeguards vision by eliminating papilledema (96%), and allows most patients to cease acetazolamide (81%). By analogy with glaucoma, if acetazolamide is the prostaglandin of IIH and CSF diversion the emergency glaucoma filter, stenting is the minimally invasive glaucoma surgery.

Case Report: Interferon-Alpha-Induced Neuromyelitis Optica Spectrum Disorder

Background and Objectives

To describe a new case of neuromyelitis optica spectrum disorder (NMOSD) induced by the administration of interferon-alpha (IFNα) and to raise awareness of this rare drug-induced disease of IFNα treatment.

Methods

A single case study and comprehensive literature review of eight cases.

Results

A 24-year-old man was diagnosed with cerebral venous thrombosis and essential thrombocythemia. He had been undergoing IFNα treatment (IFNα-2b, 3 million IU per day) without any side effects for 18 months, at which point the patient developed persistent hiccups, nausea, urinary retention, and numbness. Spinal magnetic resonance imaging revealed a longitudinal abnormality extending from the medulla to the entire spinal cord. The patient was positive for anti-aquaporin-4 antibody (AQP4-IgG) in both the serum and cerebrospinal fluid (CSF), which confirmed the diagnosis of NMOSD. Thus, recombinant IFNα-2b was suspended immediately. Because his condition did not improve after 6-day treatment of methylprednisolone pulse therapy (1,000 mg for 3 days, then 500 mg for 3 days), intravenous immunoglobulin (0.4 g/kg/day for 5 days) was administered. The patient gradually improved. Low-dose prednisolone and mycophenolate mofetil were subsequently administered as a long-term treatment. The patient was discharged with subtle limb numbness and their expanded disability status score (EDSS) was 1. At the 1-year follow-up, the patient had not relapsed and tested negative for AQP4-IgG. We further identified the eight patients with IFNα-induced NMOSD. The median onset age was 59 years, and the median time of IFNα exposure was 18 months. Optic neuritis was the most common initial symptom (five, 55.6%), followed by myelitis in three patients and area postrema syndrome in one patient. More than half (five, 55.6%) of the patients were monophasic. After IFNα discontinuation and immunotherapy, most (seven, 77.8%) patients remained relapse-free. However, only one patient was free of sequelae.

Conclusion

This study highlights the potential pathogenic risk of NMOSD of IFNα treatment. Given the high disability rates of this rare drug-induced disease, it is crucial to monitor the early manifestations of NMOSD during IFNα treatment.

Optic Disc Edema and Elevated Intracranial Pressure (ICP): A Comprehensive Review of Papilledema

Papilledema is a swelling of the optic disc secondary to elevated intracranial pressure (ICP). We analyzed 79 peer-review journal articles and provided a concise summary of the etiology, epidemiology, pathophysiology, clinical presentation, evaluation, natural history, differential diagnosis, treatment, and prognosis of papilledema. Only studies written in English with the full text available were included. Although many etiologies of papilledema exist, idiopathic intracranial hypertension is the most common and, thus, a large focus of this review.

Vogt-Koyanagi-Harada disease – A diagnostic pitfall for neurologists

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VKH is an idiopathic autoimmune disease presenting with uveomeningeal syndrome.

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Granulomatous uveitis and serious retinal detachments are the most common findings of VKH.

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VKH can masquerade as IIH by presenting with severe headache and optic disc edema.

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The characteristic retinal finding of VKH can be easily missed by direct funduscopy.

Neuro-Ophthalmologic Monitoring in the Management of Increased Intracranial Pressure From Leaking Arachnoid Cysts

BACKGROUND

Intracranial arachnoid cysts are common incidental imaging findings. They may rarely rupture, leading to the development of subdural hygromas and high intracranial pressure (ICP). Neurosurgical intervention has been advocated in the past, but recent evidence indicates that most cases resolve spontaneously. The role of neuro-ophthalmologic monitoring in identifying the few cases that have persisting vision-threatening papilledema that justifies intervention has not been emphasized.

METHODS

Retrospective review of 4 cases of leaking arachnoid cysts drawn from the files of the University of Michigan Medical Center (Michigan Medicine) between 2007 and 2018.

RESULTS

In 1 case, surgery was avoidable as papilledema resolved over time despite lingering imaging features of mass effect. In 3 cases, papilledema persisted with the threat of permanent vision loss, prompting neurosurgical intervention. In one of those cases, the fluid collection was thinly but extensively spread across both hemispheres without brain shift; yet, papilledema was pronounced. Emergent evacuation led to rapid resolution of papilledema and encephalopathy, but with residual optic nerve damage.

CONCLUSIONS

Because constitutional symptoms and even imaging are not always reliable indicators of high ICP in leaking arachnoid cysts, neuro-ophthalmologic monitoring of papilledema is valuable in identifying the cases when neurosurgical intervention is necessary.

Unilateral Isolated Paucisymptomatic Optic Disc Edema

BACKGROUND

Unilateral isolated optic disc edema (UIODE) represents a challenging clinical presentation that frequently precipitates an extensive diagnostic work-up. Patients without an apparent diagnosis despite appropriate investigations are often categorized as having "papillophlebitis," an entity that is poorly defined in the existing literature. Our aim was to describe the characteristics of a series of patients with paucisymptomatic UIODE, determine the optimal diagnostic approach to such cases, and clarify the clinical features of presumed papillophlebitis.

METHODS

We retrospectively identified 29 patients with UIODE who were seen by neuro-ophthalmologists at a single center between 2005 and 2019. Each patient presented with isolated, unilateral disc edema that was either entirely asymptomatic or associated with minimal visual symptoms. Patients underwent a comprehensive neuro-ophthalmic evaluation and several ophthalmic and systemic investigations. Data from the initial visit and all subsequent clinical visits were collected, including patient demographics, examination findings, and details of the diagnostic work-up.

RESULTS

Our 29 patients with UIODE were found to have a variety of underlying diagnoses including unilateral papilledema due to idiopathic intracranial hypertension (10 patients), optic nerve sheath meningioma (5), incipient nonarteritic anterior ischemic neuropathy (4), vitreopapillary traction (3), orbital masses (2), a peripapillary choroidal neovascular membrane (1), and presumed papillophlebitis (4). The duration of disc edema varied considerably based on the etiology, but most patients had favorable visual outcomes.

CONCLUSIONS

A systematic approach to the evaluation of UIODE, combined with long-term follow-up, led to a definite diagnosis in a majority of patients, with only 4 patients presumed to have papillophlebitis, a diagnosis the actual existence of which remains controversial.

Papilledema: A review of etiology, pathophysiology, diagnosis, and management

Papilledema is optic nerve head edema secondary to raised intracranial pressure (ICP). It is distinct from other causes of optic disk edema in that visual function is usually normal in the acute phase. Papilledema is caused by transmission of elevated ICP to the subarachnoid space surrounding the optic nerve that hinders axoplasmic transport within ganglion cell axons. There is ongoing controversy as to whether axoplasmic flow stasis is produced by physical compression of axons or microvascular ischemia. The most common cause of papilledema, especially in patients under the age of 50, is idiopathic intracranial hypertension (IIH); however, conditions that decrease cerebrospinal fluid (CSF) outflow by either causing CSF derangements or mechanically blocking CSF outflow channels, and rarely conditions that increase CSF production, can be the culprit. When papilledema is suspected clinically, blood pressure should be measured, and pseudopapilledema should be ruled out. Magnetic resonance imaging of the brain and orbits with venography sequences is the preferred neuroimaging modality that should be performed next to look for indirect imaging signs of increased ICP and to rule out nonidiopathic causes. Lumbar puncture with measurement of opening pressure and evaluation of CSF composition should then be performed. In patients not in a typical demographic group for IIH, further investigations should be conducted to assess for underlying causes of increased ICP. Magnetic resonance imaging of the neck and spine, magnetic resonance angiography of the brain, computed tomography of the chest, complete blood count, and creatinine testing should be able to identify most secondary causes of intracranial hypertension. Treatment for patients with papilledema should be targeted toward the underlying etiology. Most patients with IIH respond to weight loss and oral acetazolamide. For patients with decreased central acuity and constricted visual fields at presentation, as well as patients who do not respond to treatment with acetazolamide, surgical treatments should be considered, with ventriculoperitoneal shunting being the typical procedure of choice.

Current Perspectives on Idiopathic Intracranial Hypertension without Papilloedema

The pseudotumor cerebri syndrome embraces disorders characterised by raised intracranial pressure, where the commonest symptom is headache (90%). Idiopathic intracranial hypertension without papilloedema (IIHWOP) is increasingly recognised as a source of refractory headache symptoms and resultant neurological disability. Although the majority of patients with IIHWOP are phenotypically similar to those with idiopathic intracranial hypertension (IIH), it remains uncertain as to whether IIHWOP is nosologically distinct from IIH. The incidence, prevalence, and the degree of association with the world-wide obesity epidemic is unknown. Establishing a diagnosis of IIHWOP can be challenging, as often lumbar puncture is not routinely part of the work-up for refractory headaches. There are published diagnostic criteria for IIHWOP; however, some report uncertainty regarding a pathologically acceptable cut off for a raised lumbar puncture opening pressure, which is a key criterion. The literature provides little information to help guide clinicians in managing patients with IIHWOP. Further research is therefore needed to better understand the mechanisms that drive the development of chronic daily headaches and a relationship to intracranial pressure; and indeed, whether such patients would benefit from therapies to lower intracranial pressure. The aim of this narrative review was to perform a detailed search of the scientific literature and provide a summary of historic and current opinion regarding IIHWOP.

A novel biomarker for increased intracranial pressure in idiopathic intracranial hypertension

PURPOSE

Changes in optic disc and peripapillary structures associated with optic nerve edema in idiopathic intracranial hypertension (IIH), can be evaluated with spectral domain optical coherence tomography (SD-OCT). We aimed to evaluate the association between increased cerebrospinal fluid (CSF) opening pressure and changes in peripapillary structures detected by SD-OCT and to determine whether these changes can be used to assess the changes in CSF pressure without performing lumbar puncture (LP).

STUDY DESIGN

Retrospective study METHODS: We included 54 eyes of 28 patients with bilateral papilledema who had peripapillary SD-OCT imaging within 24 h before the LP. Correlation between CSF pressure and peripapillary OCT parameters including maximal retinal thickness, maximal anterior retinal projection, maximal retinal nerve fiber layer (RNFL) thickness and Bruch membrane opening (BMO) was evaluated.

RESULTS

Bruch Membrane opening and maximal RNFL thickness were significantly higher in patients with increased CSF pressure. There exist correlations between CSF pressure and BMO, maximal RNFL thickness and maximal retinal thickness. (Spearman's Rho: 0.791, 0.482 and 0.297, p < 0.001, < 0.001 and 0.029, respectively) The cut off value of BMO for the prediction of increased CSF pressure was 1785 µm, with a sensitivity of 78.8% and a specificity of 81%. The cut off value for maximal RNFL thickness was 174 µm, with a sensitivity of 75.8% and a specificity of 61.9%.

CONCLUSION

Bruch membrane opening and maximal RNFL thickness can give an idea about increased CSF pressure values in IIH patients. Thus SD-OCT can be used to detect CSF pressure changes in these patients.

Numerical Investigation on the Role of Mechanical Factors Contributing to Globe Flattening in States of Elevated Intracranial Pressure

Flattening of the posterior eye globe in the magnetic resonance (MR) images is a sign associated with elevated intracranial pressure (ICP), often seen in people with idiopathic intracranial hypertension (IIH). The exact underlying mechanisms of globe flattening (GF) are not fully known but mechanical factors are believed to play a role. In the present study, we investigated the effects of material properties and pressure loads on GF. For this purpose, we used a generic finite element model to investigate the deformation of the posterior eyeball. The degree of GF in numerical models and the significance of different mechanical factors on GF were characterized using an automated angle-slope technique and a statistical measure. From the numerical models, we found that ICP had the most important role in GF. We also showed that the angle-slope graphs pertaining to MR images from five people with high ICP can be represented numerically by manipulating the parameters of the finite element model. This numerical study suggests that GF observed in IIH patients can be accounted for by the forces caused by elevation of ICP from its normal level, while material properties of ocular tissues, such as sclera (SC), peripapillary sclera (PSC), and optic nerve (ON), would impact its severity.

Clinical and demographic differences between idiopathic intracranial hypertension patients with mild and severe papilledema

PURPOSE:

The purpose of this study was to evaluate whether papilledema severity is associated with specific demographic or clinical factors in patients with idiopathic intracranial hypertension (IIH).

MATERIALS AND METHODS:

A retrospective cohort study of consecutive IIH patients seen at one tertiary care institution between 1989 and March 31, 2017 was performed. IIH patients were classified as mild (Frisén Grade 1 or 2) or severe (Frisén Grade 4 or 5) based on grading of fundus photographs obtained at first presentation. Demographic and clinical variables including age, body mass index (BMI), gender, visual acuity, Humphrey visual field mean deviation, and cerebrospinal fluid (CSF) opening pressure were extracted from patient medical records for statistical analyses.

RESULTS:

A total of 239 patients were included in the study: 152 with mild papilledema and 87 with severe papilledema. There was no difference in age, race, BMI, or male gender between the mild and severe papilledema groups. CSF opening pressure was significantly higher in the severe papilledema group (41.89 cm of water vs. 33.69, 95% confidence interval [CI]: −10.79–−5.62, P < 0.0001). There was a significant difference in the Humphrey mean deviation (−6.38 dB compared to − 3.25 dB, 95% CI: −4.82–−1.44 dB, P < 0.001) and average logarithm of the minimum angle of resolution visual acuity at final follow-up (0.21 vs. 0.045, 95% CI: −0.299–−0.040 , P = 0.01).

CONCLUSION:

Age, race, sex, and BMI were similar in IIH patients with mild versus severe papilledema, emphasizing the importance of a dilated fundus examination to reliably stratify patients. Patients with severe papilledema are at higher risk of visual acuity and visual field loss at final follow-up.

Bilateral optic disc edema with preserved visual function not related to papilledema

Bilateral optic disc edema (ODE) with preserved visual function is typically a result of papilledema, but the causes of this finding in the absence of raised intracranial pressure have not been systematically evaluated. The goal of this study was to determine the causes of bilateral ODE with preserved visual function not related to intracranial hypertension to help in developing a differential diagnosis for this finding. We retrospectively reviewed 221 consecutive patients presenting to a tertiary neuro-ophthalmology practice over a period of 2 years. Four patients met the inclusion criteria with a mean age of 53 years (range 43 to 63), 2 patients were men and 2 were women. The final diagnoses were bilateral optic perineuritis secondary to p-ANCA vasculitis, bilateral incipient non-arteritic anterior ischemic optic neuropathy (NAION), hypertensive emergency, and intermediate uveitis. The patient with NAION developed an inferior altitudinal defect 4 months after presentation, but all other patients maintained normal visual function. The ODE resolved in all cases at a mean follow-up of 4.5 months (range 3 to 6 months). Optic disc edema with preserved visual function may not be related to papilledema, and this series indicates that optic perineuritis, incipient NAION, hypertensive emergency, and intermediate uveitis be considered in the differential diagnosis of these cases.

Optic Disc Classification by Deep Learning versus Expert Neuro-Ophthalmologists

OBJECTIVE

To compare the diagnostic performance of an artificial intelligence deep learning system with that of expert neuro-ophthalmologists in classifying optic disc appearance.

METHODS

The deep learning system was previously trained and validated on 14,341 ocular fundus photographs from 19 international centers. The performance of the system was evaluated on 800 new fundus photographs (400 normal optic discs, 201 papilledema [disc edema from elevated intracranial pressure], 199 other optic disc abnormalities) and compared with that of 2 expert neuro-ophthalmologists who independently reviewed the same randomly presented images without clinical information. Area under the receiver operating characteristic curve, accuracy, sensitivity, and specificity were calculated.

RESULTS

The system correctly classified 678 of 800 (84.7%) photographs, compared with 675 of 800 (84.4%) for Expert 1 and 641 of 800 (80.1%) for Expert 2. The system yielded areas under the receiver operating characteristic curve of 0.97 (95% confidence interval [CI] = 0.96-0.98), 0.96 (95% CI = 0.94-0.97), and 0.89 (95% CI = 0.87-0.92) for the detection of normal discs, papilledema, and other disc abnormalities, respectively. The accuracy, sensitivity, and specificity of the system's classification of optic discs were similar to or better than the 2 experts. Intergrader agreement at the eye level was 0.71 (95% CI = 0.67-0.76) between Expert 1 and Expert 2, 0.72 (95% CI = 0.68-0.76) between the system and Expert 1, and 0.65 (95% CI = 0.61-0.70) between the system and Expert 2.

INTERPRETATION

The performance of this deep learning system at classifying optic disc abnormalities was at least as good as 2 expert neuro-ophthalmologists. Future prospective studies are needed to validate this system as a diagnostic aid in relevant clinical settings. ANN NEUROL 2020;88:785-795.

Bilateral Proptosis in a Child-A Rare Manifestation of Ventriculoperitoneal Shunt Obstruction

Ventriculoperitoneal shunt (VPS) obstruction may have a myriad of presentations. We reported a case of an 11-year-old girl presenting with acute, bilateral proptosis secondary to VPS obstruction. While neuroimaging was interpreted as unremarkable, fundoscopy revealed bilateral papilledema and lumbar puncture showed elevated intracranial pressure. Neurosurgical exploration demonstrated VPS valve obstruction and a new VPS was inserted. Postoperatively, she developed a recurrent extradural hematoma, which was initially evacuated and later managed conservatively. To our knowledge, this is the first report of bilateral proptosis secondary to VPS obstruction. This case highlights the value of key clinical findings and limitations of neuroimaging.

Optic Nerve Head and Macular Optical Coherence Tomography Measurements in Papilledema Compared With Pseudopapilledema

BACKGROUND

To compare macular and optic nerve head optical coherence tomography (OCT) measurements in mild to moderate papilledema and pseudopapilledema.

METHODS

One hundred nineteen eyes of 61 patients with mild to moderate papilledema, 84 eyes of 48 patients with pseudopapilledema, and 60 eyes of 60 healthy normal individuals were enrolled in this cross-sectional study. Using Spectralis SD-OCT, macular scans with macular ganglion cell-inner plexiform layer (GCIPL) and macular retinal nerve fiber layer (RNFL) segmentation were performed and divided into 2 regions (inner and outer, with a diameter of 3 and 6 mm, respectively); in addition, Bruch membrane opening (BMO) area and peripapillary RNFL thickness were obtained.

RESULTS

BMO area was similar in papilledema (1.83 ± 0.34 mm), pseudopapilledema (1.85 ± 0.37 mm), and controls (1.85 ± 0.32 mm). Average inner region macular GCIPL thickness in the papilledema, pseudopapilledema, and control groups was 87.2 ± 14.4 μm, 90.8 ± 6.1 μm, and 91.2 ± 9.8 μm, respectively (P > 0.05). Outer temporal region macular GCIPL was significantly thinner in the papilledema group compared with control group (P = 0.01). By contrast, outer inferior and outer nasal macular RNFL sectors were significantly thicker in the papilledema group compared with control groups (P = 0.01 and P < 0.01, respectively). Those measures were not different between pseudopapilledema and control eyes.

CONCLUSIONS

In papilledema eyes, outer temporal region macular GCIPL thickness decreased and outer inferior and outer nasal macular RNFL sectors thickness increased compared with the control group. These changes were not observed in the pseudopapilledema group.

A Deep-Learning Approach for Automated OCT En-Face Retinal Vessel Segmentation in Cases of Optic Disc Swelling Using Multiple En-Face Images as Input

Purpose

In cases of optic disc swelling, segmentation of projected retinal blood vessels from optical coherence tomography (OCT) volumes is challenging due to swelling-based shadowing artifacts. Based on our hypothesis that simultaneously considering vessel information from multiple projected retinal layers can substantially increase vessel visibility, in this work, we propose a deep-learning-based approach to segment vessels involving the simultaneous use of three OCT en-face images as input.

Methods

A human expert vessel tracing combining information from OCT en-face images of the retinal pigment epithelium (RPE), inner retina, and total retina as well as a registered fundus image served as the reference standard. The deep neural network was trained from the imaging data from 18 patients with optic disc swelling to output a vessel probability map from three OCT en-face input images. The vessels from the OCT en-face images were also manually traced in three separate stages to compare with the performance of the proposed approach.

Results

On an independent volume-matched test set of 18 patients, the proposed deep-learning-based approach outperformed the three OCT-based manual tracing stages. The manual tracing based on three OCT en-face images also outperformed the manual tracing using only the traditional RPE en-face image.

Conclusions

In cases of optic disc swelling, use of multiple en-face images enables better vessel segmentation when compared with the traditional use of a single en-face image.

Translational Relevance

Improved vessel segmentation approaches in cases of optic disc swelling can be used as features for an improved assessment of the severity and cause of the swelling.

Optical coherence tomography use in idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is a condition in which elevated pressure in the cerebrospinal fluid can lead to optic nerve head (ONH) dysfunction and subsequent visual impairment. Physicians are currently limited in their ability to monitor and manage this condition, as clinical symptoms and exam findings are often delayed in response to changes in intracranial pressure. In order to find other biomarkers of disease, researchers are using imaging modalities such as optical coherence tomography (OCT) to observe microscopic changes in the eye in this condition. OCT can create 2-dimensional and 3-dimensional high definition images of the retina of the ONH and has been used to study various conditions such as glaucoma and multiple sclerosis. Numerous studies have used OCT in IIH as well, and they have shown that certain retinal layers and the ONH change in thickness and shape in both the short and long term with intracranial pressure changes. OCT is a promising modality for clinical and scientific evaluation of IIH as it is a noninvasive and practical tool to obtain in depth images. This review will discuss how OCT can be used to assess a patient with IIH, both before and after treatment, along with its limitations and future applications.

Ophthalmological manifestation in patients of tuberculous meningitis

BACKGROUND

Vision impairment, blindness in particular is a devastating complication in patients with tuberculous meningitis. However, information regarding ophthalmological manifestation and its impact on vision is sparse in the literature. This study evaluated the spectrum of ophthalmological manifestations in tuberculous meningitis, including retinal nerve fiber layer thickness assessment by optic coherence tomography and its correlation with visual and clinical outcome.

METHODS

This was a prospective observational study done from October 2015 to March 2017. Consecutive patients of tuberculous meningitis, diagnosed as per consensus case definition were included in the study. The patients were divided into two categories: uncomplicated and complicated tuberculous meningitis. Clinical evaluation, cerebrospinal fluid examination and contrast enhanced MRI of brain was done. Detailed ophthalmological evaluation including optic coherence tomography was done in all patients. All the patients were followed for 6 months. The primary outcome was blindness or low vision after 6 months. The secondary outcome was death or severe disability after 6 months. It was defined as modified Barthel index (MBI) ≤ 12 at 6 months (including disability plus death). Appropriate statistical analysis was done.

RESULTS

Out of 101 patients of tuberculous meningitis, 47 patients of TBM belonged to uncomplicated category, while 54 patients were of complicated group. The visual impairment was present in 24 out of 101 (23.76%) patients out of which 20 (19.8%) patients had low vision while 4 (3.96%) had blindness. The visual impairment was more evident in complicated group, low vision 0.03 (1.2-31.5). The most common abnormality on fundus examination was papilledema (22.8%). The complicated group had more incidence <0.0001 (19.6-48). Optic atrophy was found in three patients while choroid tubercles were found in eight patients (all complicated TBM group). RNFL thinning was noted in 10 patients in both the eyes. On univariate analysis, presence of diplopia at baseline, impairment of color vision at baseline, visual impairment at baseline, cranial nerve VIth involvement, optic atrophy and papilledema at baseline, RNFL thinning, abnormal VEP and baseline MBI were associated with poor visual outcome. On multivariate analysis, none of the factors were found to be independently associated with poor visual outcome. On univariate analysis, many factors including baseline MRC staging, altered sensorium, seizure, hemiparesis, basal exudates, infarcts, optochiasmaticarachnoiditis, visual impairment at baseline were found to be associated with poor clinical outcome at 6 months. On multivariate analysis, presence of seizure (P = 0.047, odds ratio = 78.59, 95% confidence interval (1.07-578.72)) was the only factor found to be independently associated with poor outcome.

CONCLUSION

Wide spectrum of ophthalmological manifestation was observed in patients of tuberculous meningitis. The visual impairment was more evident in complicated tuberculous meningitis. Ophthalmological findings like optic atrophy, papilledema and RNFL thinning were associated with poor visual outcome on univariate but not multivariate analysis. Visual impairment at baseline, among other factors was associated with poor clinical outcome on univariate analysis, whereas seizure was the only factor independently associated with poor outcome on multivariate analysis.

Contrast-Enhanced 3D-FLAIR Imaging of the Optic Nerve and Optic Nerve Head: Novel Neuroimaging Findings of Idiopathic Intracranial Hypertension

BACKGROUND AND PURPOSE

The sensitivity of contrast-enhanced 3D-FLAIR has not been assessed in patients with idiopathic intracranial hypertension. The purpose of this study was to evaluate whether hyperintensity of the optic nerve/optic nerve head on contrast-enhanced 3D-FLAIR imaging is associated with papilledema in patients with idiopathic intracranial hypertension.

MATERIALS AND METHODS

A retrospective review was conducted from 2012 to 2015 of patients with clinically diagnosed idiopathic intracranial hypertension and age- and sex-matched controls who had MR imaging with contrast-enhanced 3D-FLAIR. Two neuroradiologists graded each optic nerve/optic nerve head on a scale of 0-3. This grade was then correlated with the Frisén Scale, an ophthalmologic scale used for grading papilledema from 0 (normal) to 5 (severe edema). To estimate the correlation between the MR imaging and Frisén scores, we calculated the Kendall τ coefficient.

RESULTS

Forty-six patients (3 men, 43 women) with idiopathic intracranial hypertension and 61 controls (5 men, 56 women) with normal findings on MR imaging were included in this study. For both eyes, there was moderate correlation between the 2 scales (right eye: τ = 0.47; 95% CI, 0.31-0.57; left eye: τ = 0.38; 95% CI, 0.24-0.49). Interreader reliability for MR imaging scores showed high interreader reliability (right eye: κ = 0.76; 95% CI, 0.55-0.88; left eye: κ = 0.87; 95% CI, 0.78-0.94). Contrast-enhanced 3D-FLAIR imaging correlates with the Frisén Scale for moderate-to-severe papilledema and less so for mild papilledema.

CONCLUSIONS

Hyperintensity of the optic nerve/optic nerve head on contrast-enhanced 3D-FLAIR is sensitive for the detection of papilledema in patients with idiopathic intracranial hypertension, which may be useful when prompt diagnosis is crucial.

Optical Coherence Tomography Angiography in Papilledema Compared With Pseudopapilledema

Purpose

The purpose of this study is to evaluate differences in optical coherence tomography angiography (OCT-A) findings between patients with papilledema and pseudopapilledema.

Methods

In this prospective, comparative study, 41 eyes of 21 subjects with papilledema, 27 eyes of 15 subjects with pseudopapilledema, and 44 eyes of 44 healthy normal subjects were included and were imaged using OCT-A. In addition to peripapillary total vasculature maps obtained with commercial vessel density mapping, major vessel removal using customized image analysis software was also used to measure whole image capillary density and peripapillary capillary density (PCD). Peripapiilary retinal nerve fiber layer (RNFL) and macular ganglion cell complex (GCC) were recorded.

Results

Average RNFL thicknesses were greater in papilledema eyes than in pseudopapilledema and control subjects. GCC thickness was not different among three groups. Peripapillary vasculature values were significantly lower in papilledema (58.5 ± 6.1%) and pseudopapilledema (58.9 ± 4.7%) eyes compared with healthy eyes (63.2 ± 3.1%) using commercial machine software, without a difference between papilledema and pseudopapilledema eyes. However, using our customized software, peripapillary "capillary" density of papilledema eyes was 29.8 ± 9.4%, which was not significantly different from healthy subjects (31.8 ± 7.4%; P = 0.94). Pseudopapilledema eyes with peripapillary density of 25.5 ± 8.3% had significantly lower capillary values compared with control eyes (P = 0.01). There was a significantly lower whole image and nasal sector peripapillary capillary density of inner retina in pseudopapilledema eyes than papilledema eyes (P = 0.03 and P = 0.02, respectively).

Conclusions

Whole image and nasal peripapillary sector capillary densities using OCT-A had diagnostic accuracy for differentiating true and pseudo-disc swelling.

Association Between Peripapillary Bruch's Membrane Shape and Intracranial Pressure: Effect of Image Acquisition Pattern and Image Analysis Method, a Preliminary Study

Background/Aims: High intracranial pressure (ICP) is associated with changes in peripapillary Bruch's membrane (pBM) shape on optical coherence tomography (OCT) images of the optic nerve head. It is not known if image acquisition pattern and analysis method impact this association.

Materials and Methods: Cross sectional OCT scans of the optic nerve head were obtained at six angles using a radial scan pattern in 21 subjects immediately prior to ICP measurement via lumbar puncture. On each image, Bruch's membrane was manually segmented and defined by either 14 or 16 semi-landmarks and either rater identified, or distance identified boundaries. For each of these four image analysis strategies, geometric morphometric analysis identified the first principal component of Bruch's membrane shape for all images and for the set of images taken at each angle. Repeated measures ANOVA of the first principal component magnitude (PC1) for all images assessed for shape difference between image angles. Linear generalized estimating equation models assessed association between angle specific first principal component magnitudes (PC1) and ICP for each angle. Receiver operating characteristic analysis assessed angle specific PC1s' ability to differentiate elevated from normal ICP.

Results: The first principal component represented deflection into the vitreous for all scan angles, but quantitatively differed across scan angles (p < 0.005, repeated measures ANOVA). Angle specific first principal components were positively correlated with ICP (p < 0.005 for all angles, generalized estimating equation models). All angle specific first principal components showed excellent ability to classify ICP (area under curve ≥ 0.8 for all). These results were independent from image analysis strategy.

Discussion: Though qualitative changes in Bruch's membrane shape are similar regardless of cross-sectional angle of the 2-D OCT scan, they differ quantitatively between OCT scan angles, meaning that pBM is not axially symmetric and therefore PC1 extracted from different 2-D scan angles can't be compared between individuals. However, we do not identify an optimal scan angle for classification of ICP since there is a similarly strong linear relationship between the first principal component of shape and ICP and angle specific first principal components of Bruch's membrane shape showed similarly excellent ability to differentiate elevated from normal ICP. The results support development of Bruch's membrane shape extracted from 2-D cross sectional optic nerve head OCT scans as a biomarker of ICP and emphasize the importance of consistency of scan angle. This is relevant for developing diagnostic protocols that use OCT to detect high ICP states.

Optic nerve appearance as a predictor of visual outcome in patients with idiopathic intracranial hypertension

BACKGROUND/AIMS

It remains unclear whether the presence of optic disc haemorrhages (ODH) or cotton wool spots (CWS) at presentation in patients with papilloedema from idiopathic intracranial hypertension (IIH) has prognostic value. The aim of this study was to determine if optic disc appearance at presentation predicts visual outcome in patients with IIH.

METHODS

Retrospective study of 708 eyes of 360 consecutive patients with IIH who had baseline optic disc photographs before or within 30 days of their diagnostic lumbar puncture and initiation of medical treatment. Optic disc photographs were independently graded by three ophthalmologists in a standardised manner. Visual function was assessed using Snellen converted to logMAR visual acuity, Humphrey mean deviation and visual field grade.

RESULTS

At least one ODH was found in 201 (28.4%) eyes, at least one CWS was found in 101 (14.3%) eyes and 88 eyes had both ODH and CWS (12.4%). At presentation, Frisén grade was associated with the presence and severity of ODH and CWS (p<0.001). ODH were associated with a worse visual acuity and CWS were associated with a worse visual field grade and mean deviation at presentation (p<0.05). Frisén grade was associated with worse visual function at presentation and final follow-up (p<0.001). Neither ODH nor CWS at presentation were associated with visual function at final follow-up when controlling for the Frisén grade.

CONCLUSIONS AND RELEVANCE

ODH and CWS at baseline are not independent predictors of final visual function in IIH when controlling for the severity of papilloedema.

Cases of visual impairment caused by cerebral venous sinus occlusion-induced intracranial hypertension in the absence of headache

Background

Cerebral venous sinus thrombosis or stenosis (here collectively referred to as cerebral venous sinus occlusion, CVSO) can cause chronically-elevated intracranial pressure (ICP). Patients may have no neurological symptoms other than visual impairment, secondary to bilateral papilledema. Correctly recognizing these conditions, through proper ophthalmological examination and brain imaging, is very important to avoid delayed diagnosis and treatment.

Case presentation

We report a case series of 3 patients with chronic CVSO, who were admitted to an ophthalmological department in Chongqing, China, from 2015 March to 2017 February. All patients presented with decreased vision and bilateral papilledema, but had no headache or other neurological symptoms. The visual fields of all patients were impaired. Flash visual evoked potentials (VEPs) in two patients showed essentially normal peak time of P2 wave, and pattern VEPs in one patient displayed decreased P100 amplitude in one eye, while a normal P100 wave in the other eye. In all patients, lumbar puncture (LP) revealed significantly elevated ICP. And magnetic resonance venography (MRV) demonstrated cerebral venous sinus abnormalities in every patient: one right sigmoid sinus thrombosis, one superior sagittal sinus thrombosis, and one right transverse sinus stenosis.

Conclusions

CVSO can cause chronically-elevated ICP, leading to bilateral papilledema and visual impairment. A considerable amount of patients have no apparent neurological symptoms other than visual loss. Unlike other optic nerve lesions, such as neuritis or ischemic optic neuropathy, the optic disc edema in CVSO is usually bilateral, the flash or pattern VEP is often normal or only mildly affected, and patients are often not sensitive to steroid therapy. CVSO should be suspected in such patients when unenhanced brain imaging is normal. Further investigations, such as LP and contrast-enhanced imaging (MRV and digital subtraction angiography), should be performed to diagnose or exclude CVSO.

Early Macular Vessel Density Loss in Acute Ischemic Optic Neuropathy Compared to Papilledema: Implications for Pathogenesis

PURPOSE

This study compares macular and parafoveal vasculature in patients with optic disc swelling.

METHODS

Twenty eyes with acute nonarteritic anterior ischemic optic neuropathy (NAION), 39 eyes with papilledema at first presentation, and 22 eyes of normal subjects were imaged using optical coherence tomography angiography (OCT-A). Macular ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer thicknesses were measured in addition to macula and parafovea superficial and deep vasculature.

RESULTS

Age- and gender-mixed models showed that the macular and parafoveal superficial and deep vasculature density values were significantly lower in NAION eyes than control eyes (P ≤ 0.0001 for all comparisons). All vessel density values were not statistically different between papilledema eyes and control eyes. Whole superficial and deep macula vasculature in the NAION eyes (45.9% ± 4.2%, 50.9% ± 6.5%) were significantly lower than in papilledema eyes (50.5% ± 4.6%, 57.3% ± 6.1%) (P = 0.03 and P = 0.01, respectively). No significant differences in GCC thickness were observed among NAION, papilledema, and control eyes. Whole superficial and deep macular vasculatures, but not macular GCC thickness, were significantly correlated with visual field mean deviation (r = 0.39, P = 0.001 and r = 0.41, P < 0.001, respectively).

CONCLUSIONS

Macular OCT-A is able to show early macular vasculature abnormalities associated with optic nerve damage; this change occurs before detectable macular GCC atrophy.

TRANSLATIONAL RELEVANCE

Macular vessel density measurement offers an opportunity to evaluate the optic nerve damage at initial presentation, but further longitudinal studies are needed.

Optical Coherence Tomography Angiography in Optic Disc Swelling

PURPOSE

To compare optical coherence tomography angiography (OCT-A) of peripapillary total vasculature and capillaries in patients with optic disc swelling.

DESIGN

Cross-sectional study.

METHODS

Twenty nine eyes with acute nonarteritic anterior ischemic optic neuropathy (NAION), 44 eyes with papilledema, 8 eyes with acute optic neuritis, and 48 eyes of normal subjects were imaged using OCT-A. Peripapillary total vasculature information was recorded using a commercial vessel density map. Customized image analysis with major vessel removal was also used to measure whole-image capillary density and peripapillary capillary density (PCD).

RESULTS

Mixed models showed that the peripapillary total vasculature density values were significantly lower in NAION eyes, followed by papilledema eyes and control eyes, using commercial software (P < .0001 for all comparisons). The customized software also showed significantly lower PCD of NAION eyes compared with papilledema eyes (all P < .001), but did not show significant differences between papilledema and control subjects. Our software showed significantly lower whole image and PCD in eyes with optic neuritis than papilledema. There was no significant difference between NAION and optic neuritis using our software. The area under the receiver operating curves for discriminating NAION from papilledema eyes and optic neuritis from papilledema eyes was highest for whole-image capillary density (0.94 and 0.80, respectively) with our software, followed by peripapillary total vasculature (0.9 and 0.74, respectively) with commercial software.

CONCLUSIONS

OCT-A is helpful to distinguish NAION and papillitis from papilledema. Whole-image capillary density had the greatest diagnostic accuracy for differentiating disc swelling.

Diseases of the retina and the optic nerve associated with obstructive sleep apnea

Many associations between ocular disorders and obstructive sleep apnea (OSA) have been studied, such as nonarteritic anterior ischemic optic neuropathy, glaucoma, papilledema, retinal vein occlusion, eyelid hyperlaxity, lower-eyelid ectropion and recurrent corneal erosions. The objective of this review is to synthetize the possible vascular disorders of the retina and the optic nerve associated with sleep apnea patients and to discuss the underlying pathophysiological hypotheses. Main mechanisms involved in the ocular complications of OSA are related to intermittent hypoxia, sympathetic system activation, oxidant stress, and deleterious effects of endothelin 1. The main evidence-based medicine data suggest that OSA should be screened in patients with ischemic optic neuropathy and diabetic retinopathy. The effect of OSA treatment and emerging therapies are discussed.

Objective Measures of Visual Function in Papilledema

Visual function is an important parameter to consider when managing patients with papilledema. Though the current standard of care uses standard automated perimetry (SAP) to obtain this information, this test is inherently subjective and prone to patient errors. Objective visual function tests including the visual evoked potential, pattern electroretinogram, photopic negative response of the full field electroretinogram, and pupillary light response have the potential to replace or supplement subjective visual function tests in papilledema management. This article reviews the evidence for use of objective visual function tests to assess visual function in papilledema and discusses future investigations needed to develop them as clinically practical and useful measures for this purpose.

Correlation between papilledema grade and diffusion-weighted magnetic resonance imaging in idiopathic intracranial hypertension

BACKGROUND

To explore the relationship between diffusion-weighted magnetic resonance imaging (DWI) hyperintensity of the optic nerve head (ONH) and papilledema grade in patients with idiopathic intracranial hypertension (IIH).

METHODS

A retrospective chart review was conducted of patients with definitively diagnosed IIH by clinical examination and visual field (VF) analysis who underwent orbital magnetic resonance imaging (MRI) within 4 weeks of diagnosis. A neuroradiologist masked to the diagnosis assessed the results of DWI for each eye independently and graded the signal intensity of the ONH into none, mild, and prominent categories. DWI grading was compared with papilledema grade and visual field mean deviation (VFMD) by Spearman rank correlation analysis and t-tests.

RESULTS

Forty-two patients were included in the study. A statistically significant difference (P = 0.0195) was found between papilledema grade and patients with prominent DWI findings (n = 16; mean papilledema grade 3.75 ± 1.25) vs mild or no ONH hyperintensity (n = 26; mean papilledema grade 2.79 ± 1.24) at the time of initial diagnosis. DWI hyperintensity of the ONH at diagnosis was also found to be significantly correlated with the degree of papilledema at follow-up (ρ = 0.39, P = 0.0183) but not with VFMD.

CONCLUSIONS

We found a significant correlation between the severity of papilledema and ONH hyperintensity on DWI in patients with IIH but not with VF loss or other visual parameters. These findings may offer insight into the pathophysiology of papilledema in IIH and provide a surrogate marker for the presence and severity of papilledema.

The Photopic Negative Response in Idiopathic Intracranial Hypertension

PURPOSE

To evaluate the photopic negative response (PhNR) as an index of retinal ganglion cell (RGC) function in idiopathic intracranial hypertension (IIH).

METHODS

Amplitude and implicit time of the PhNR, as elicited by full-field, brief-luminance flashes, was measured in IIH (n = 10) and visually normal control (n = 15) subjects. Visual function was assessed in IIH subjects using standard automated perimetry mean deviation (SAP-MD) scores. Optic nerve structure was evaluated using the Frisén papilledema grading scale (FPG). Macula ganglion cell complex volume (GCCV) was extracted from optical coherence tomography images to assess RGC loss.

RESULTS

Median PhNR amplitude was significantly lower in IIH subjects compared with control subjects (P = 0.015, Mann-Whitney Rank Sum [MW]), but implicit time was similar (P = 0.54, MW). In IIH subjects, PhNR amplitude and SAP-MD were correlated (Pearson's r = 0.78, P = 0.008). Ganglion cell complex volume was correlated with both SAP-MD (r = 0.72, P = 0.019) and PhNR amplitude (r = 0.77, P = 0.009). Multivariate linear regression models demonstrated that the correlation between GCCV and PhNR amplitude was improved by accounting for FPG in the model (r = 0.94, P < 0.0001), but the correlation between GCCV and SAP-MD was not (r = 0.74, P = 0.009).

CONCLUSIONS

Photopic negative response amplitude, which can be decreased in IIH subjects, correlates well with a clinical measure of visual function (SAP-MD). In multivariate models, it correlated with both an imaging measure of chronic ganglion cell injury (GCCV) and a clinical measure of acute optic nerve head pathology (FPG). Further studies are needed to determine the clinical utility of PhNR as a marker for diagnosis and monitoring of IIH.

Effects of lowering cerebrospinal fluid pressure on the shape of the peripapillary retina in intracranial hypertension

PURPOSE

To analyze the deformations of the peripapillary retinal pigment epithelium-basement membrane (ppRPE/BM) layer in response to procedures that lower intracranial pressure (ICP). Second, to demonstrate how shape changes may complement the mean retinal nerve fiber layer (RNFL) thickness as a measure of intracranial hypertension (ICH) and papilledema.

METHODS

We used geometric morphometrics on spectral-domain optical coherence tomography images to analyze shape change of the ppRPE/BM layer after several interventions that lower cerebrospinal fluid (CSF) pressure. We also evaluated the effects of pressure-lowering interventions on both the anterior-posterior displacement of ppRPE/BM and the mean RNFL thickness. Forty-one patients with ICH and papilledema were studied before and after lumbar puncture (20), CSF shunt (9), and medical treatment of idiopathic ICH (23). We also compared the shape of 30 normal subjects to 23 patients whose papilledema resolved after medical treatment.

RESULTS

The ppRPE/BM-layer in ICH and papilledema is characterized by an asymmetric anterior deformation that moves posteriorly and becomes more V-shaped after each pressure-lowering intervention. The differences were statistically significant for all three groups. These shape changes also occur in patients with ongoing ICH who have secondary optic atrophy (without papilledema). Posterior displacement at the margin of the ppRPE/BM layer correlated strongly with overall shape changes.

CONCLUSIONS

The subsurface contour of the ppRPE/BM layer is a dynamic property that changes with CSF pressure-lowering interventions. It can supplement the RNFL thickness as an indirect gauge of ICP and is particularly helpful in patients with secondary optic atrophy. Direct measurements of displacement at the basement membrane opening may serve as a more convenient office-based surrogate for shape analysis.

The usefulness of multimodal imaging for differentiating pseudopapilloedema and true swelling of the optic nerve head: a review and case series

Ophthalmic practitioners have to make a critical differential diagnosis in cases of an elevated optic nerve head. They have to discriminate between pseudopapilloedema (benign elevation of the optic nerve head) and true swelling of the optic nerve head. This decision has significant implications for appropriate patient management. Assessment of the optic disc prior to the advanced imaging techniques that are available today (particularly spectral domain optical coherence tomography and fundus autofluorescence), has mainly used diagnostic tools, such as funduscopy and retinal photography. As these traditional methods rely on the subjective assessment by the clinician, evaluation of the elevated optic nerve head to differentiate pseudopapilloedema from true swelling of the optic nerve head can be a challenge in clinical practice with patients typically referred for further neuroimaging investigation when the diagnosis is uncertain. The use of multimodal ocular imaging tools such as spectral domain optical coherence tomography, short wavelength fundus autofluorescence and ultrasonography, can potentially aid in the differentiation of pseudopapilloedema from true swelling of the optic nerve head, in conjunction with other clinical findings. By doing so, unnecessary patient costs and anxiety in the case of pseudopapilloedema can be reduced, and appropriate urgent referral and management in the case of true swelling of the optic nerve head can be initiated.

The Pseudotumor Cerebri Syndrome: A Unifying Pathophysiological Concept for Patients with Isolated Intracranial Hypertension with Neither Mass Lesion Nor Ventriculomegaly

In 1991 we proposed that while the syndrome of isolated intracranial hypertension might have many definite and probable causes, it has nonetheless a single unifying pathophysiological mechanism: namely, impairment of cerebrospinal fluid (CSF) reabsorption. For that reason, we also proposed then that it is best described by a single, unifying, inclusive term, namely, pseudotumor cerebri syndrome. Although it appears that there is, as far as nomenclature is concerned, now international agreement, there is as yet no agreement on pathophysiology and classification. Herein we outline our views on these matters and give our reasons.

Quantification of peripapillary total retinal volume in pseudopapilledema and mild papilledema using spectral-domain optical coherence tomography

PURPOSE

To distinguish differences in retinal nerve fiber layer (RNFL) thickness and peripapillary total retinal volume between eyes with papilledema, pseudopapilledema, and normal findings.

DESIGN

Cohort study.

METHODS

Forty-two eyes with mild papilledema, 37 eyes with congenitally elevated optic disc (pseudopapilledema), and 34 normal eyes met the inclusion criteria at 1 academic institution (in Iran) and underwent neuro-ophthalmic examination. Spectral-domain optical coherence tomography scans surrounding the optic disc were performed in each eye of patients and subjects. Main outcome measures were mean RNFL thickness and peripapillary total retinal volume measurements (inner and outer ring volumes) that were compared between groups, using the generalized estimating equation approach. Area under receiver operating characteristic curves were also calculated.

RESULTS

A statistically significant difference was found in mean RNFL thickness between both groups of patients with papilledema and pseudopapilledema and normal subjects. Average inner peripapillary total retinal volume in the papilledema, pseudopapilledema, and control groups were 1.95 ± 0.24 mm(3), 1.81 ± 0.23 mm(3), and 1.06 ± 0.10 mm(3), respectively. Average outer peripapillary total retinal volume in the papilledema and pseudopapilledema groups were 2.68 ± 0.49 mm(3) and 2.03 ± 0.24 mm(3), respectively (P < .001). However, the outer ring peripapillary total retinal volume was not different between pseudopapilledema and normal (1.90 ± 0.11 mm(3)) eyes (P = .17). Area under the curve to discriminate pseudopapilledema vs papilledema eyes for average RNFL thickness and inner and outer peripapillary total retinal volumes was 0.82, 0.68, and 0.88, respectively.

CONCLUSION

Outer peripapillary total retinal ring volumes might be useful in differentiating papilledema from pseudopapilledema.

Association between visual parameters and neuroimaging features of idiopathic intracranial hypertension

BACKGROUND/AIMS

Papilledema refers to optic disc swelling resulting from high intracranial pressure (ICP). The precise mechanism by which papilledema occurs remains uncertain. Although orbital neuroimaging features associated with papilledema are well-described, it is unclear whether these findings correlate with visual function. Idiopathic Intracranial Hypertension (IIH) is a condition in which the intracranial pressure is elevated with no obvious cause, causing papilledema and visual loss. The utility of papilledema and IIH neuroimaging findings as a surrogate marker for visual loss, or a predictor of visual loss, is understudied. This retrospective cross-sectional review aims to correlate parameters of visual function with orbital magnetic resonance imaging (MRI) findings.

METHODS

Patients meeting criteria for IIH who had received orbital imaging within 4 weeks of examination were included. Visual parameters of papilledema grade, visual field mean deviation, and visual acuity were correlated with neuroimaging features, including optic nerve thickness, and optic nerve sheath thickness, among others. All MRI scans were reviewed by a neuroradiologist blinded to clinical status. Spearman rank correlations and t-tests were generated with SAS (v9.2).

RESULTS

Thirty five patients were included. No significant relationships were found between the main visual parameters of papilledema grade and visual field mean deviation, and MRI findings.

CONCLUSIONS

We found no significant correlation between visual parameters and imaging features of papilledema. This might indicate that MRI features may provide insight into the structural changes that occur in papilledema, but may not be helpful when making clinical management decisions for patients with IIH in particular, and papilledema in general.

Automated quantitation of the posterior scleral flattening and optic nerve protrusion by MRI in idiopathic intracranial hypertension

BACKGROUND AND PURPOSE

Subjective determination of the posterior sclera flattening and optic nerve protrusion in MRI is challenging because of the 3D nature of the globe morphology. This study aims to develop and compare quantitative measures of globe flattening and optic nerve protrusion with subjective rating, and assess relationships with papilledema grade and intraocular and CSF pressures.

MATERIALS AND METHODS

Data of 34 globes from 7 overweight female patients with idiopathic intracranial hypertension and 6 age- and weight-matched healthy female control subjects were assessed, as well as a subcohort of 4 of the patients with idiopathic intracranial hypertension who underwent follow-up MR imaging 2 weeks after lumbar puncture and initiation of treatment with acetazolamide. MR imaging examination included a 3D CISS sequence on 1.5T and 3T scanners with 0.6-mm isotropic resolution. Subjective ratings of globe flattening were obtained by experienced and inexperienced readers. Quantitative measures of globe flattening, nerve protrusion, and maximal deformation were derived by use of a 2D map of the distances from the globe center to the posterior wall.

RESULTS

Contingency coefficients for globe flattening agreements with subjective rating by the experienced and inexperienced readers were 0.72 and 0.56, respectively. Mean values of the 3 deformation measures were significantly poorer in the idiopathic intracranial hypertension group, with nerve protrusion demonstrating the strongest difference (P = .0002). Nerve protrusion was most strongly associated with papilledema grade with a contingency coefficient of 0.74 (P = .01), whereas globe flattening was negatively correlated with intraocular pressure (R = -0.75, P < .0001). Maximal deformation was negatively associated with CSF opening pressure (R = -0.86, P = .0001). After treatment, only the changes in nerve protrusion and maximal deformation were significant.

CONCLUSIONS

Automated measures of globe deformation improve reliability over subjective rating. Of the 2 globe deformation measures, nerve protrusion had the strongest predictive value for papilledema grade and had the highest sensitivity for assessment of treatment efficacy in idiopathic intracranial hypertension.

Fulminant Idiopathic Intracranial Hypertension With Malignant Systemic Hypertension-A Case Report

We describe a young woman who presented with malignant systemic hypertension and fulminant idiopathic intracranial hypertension. This is a rare combination, but both diagnoses should be considered in patients with optic disc swelling in whom cerebral imaging does not suggest an alternative cause. In this case, malignant hypertension was identified and treated before the idiopathic intracranial hypertension was recognised. Visual failure was evident at presentation and prior to blood pressure manipulation. It is likely that a combination of both conditions increased the vulnerability of the optic nerve head to ischaemic damage. It is also possible that reducing blood pressure in such patients, without treating coexisting raised intracranial pressure, may compound an already compromised ciliary arterial perfusion pressure. We therefore recommend careful blood pressure measurement in all patients presenting with idiopathic intracranial hypertension and advise that lumbar puncture is performed in patients with malignant hypertension with optic disc oedema, particularly in overweight young females.

Hyperintense optic nerve heads on diffusion-weighted imaging: a potential imaging sign of papilledema

BACKGROUND AND PURPOSE

Changes at the optic nerve head on DWI in the presence of papilledema have not been systematically studied. The purpose of this study was to evaluate if hyperintensity of ON heads on DWI is associated with papilledema.

MATERIALS AND METHODS

In this retrospective study, 19 patients (4 men, 15 women; median age, 32 years) with papilledema and 20 control participants (7 men, 13 women; median age, 48 years) who had undergone prior MR imaging of the brain were identified. Two neuroradiologists blinded to the diagnosis independently reviewed the DWI for the presence of hyperintense signal at the ON head of each eye. If present, they graded the signal as mild or prominent. Groups with and without papilledema were compared for the prevalence of ON head hyperintensity by using the Fisher exact test, with analyses performed both for groups of patients and for individual eyes. Presence of ON head hyperintensity was also studied as a function of Frisen papilledema grade on fundoscopy, when available.

RESULTS

Hyperintensity of the ON heads on DWI was significantly associated with papilledema (P = .001). For the 2 readers, hyperintensity at both ON heads was 26.3% and 42.1% sensitive and 100% specific in the detection of papilledema. The presence of unilateral ON head hyperintensity was not specific for papilledema and was invariably graded as mild when seen in the control group. Patients with higher papilledema grades had a higher prevalence of hyperintensity at the ON heads.

CONCLUSIONS

Hyperintensity of the ON heads on DWI can serve as a useful imaging marker for papilledema, especially if bilateral. Its absence, however, does not exclude papilledema.

MR imaging of papilledema and visual pathways: effects of increased intracranial pressure and pathophysiologic mechanisms

Papilledema, defined as swelling of the optic disc, frequently occurs in the setting of increased ICP and in a variety of medical conditions, including pseudotumor cerebri, sinus thrombosis, intracerebral hemorrhage, frontal lobe neoplasms, and Chiari malformation. Noninvasive imaging of the ON is possible by using MR imaging, with a variety of findings occurring in the setting of papilledema, including flattening of the posterior sclera, protrusion of the optic disc, widening of the ONS, and tortuosity of the ON. Early recognition of papilledema and elevated ICP is of paramount importance for ensuring restoration of vision. Newer advanced MR imaging techniques such as fMRI and DTI may prove useful in the future to assess the potential effects of papilledema on retinal and visual pathway integrity.