Optical coherence tomography represents a sensitive and reliable tool for routine monitoring of idiopathic intracranial hypertension with and without papilledema

Optical coherence tomography surpasses fundus imaging and intracranial pressure measurement in monitoring idiopathic intracranial hypertension

We aim to evaluate the retinal nerve fiber layer (RNFL) thickness measured with optical coherence tomography (OCT) in comparison with papilledema grade, and to assess the relationship between RNFL thickness, papilledema grade, and intracranial pressure (ICP) in idiopathic intracranial hypertension (IIH). Sixty-five patients with active IIH (AIIH) with papilledema, 39 with chronic IIH (CIIH) without papilledema and 80 healthy controls (HC) were examined with OCT and fundus imaging. RNFL thickness, papilledema grade and ICP level were assessed in 55 with AIIH and 26 with CIIH. RNFL thickness was significantly higher in AIIH compared to CIIH or HC. RNFL thickness correlated strongly with papilledema grade (coefficient 0.78, p < 0.01) and moderately with ICP (coefficient 0.569, p < 0.01). RNFL thickness was associated with papilledema progression (R2 = 0.656, p < 0.01): specifically, with increases of 9 µm from normal to mild grade (p > 0.05), 91 µm from normal to moderate (p < 0.01), and 214 µm from normal to severe (p < 0.01). ICP showed a weaker correlation with papilledema grades (R2 = 0.339, p < 0.05), with significant increase (8 cm H2O, p < 0.01) only from normal to severe papilledema. RNFL correlated strongly with papilledema grade and moderately with ICP levels. RNFL thickness increased proportionally per papilledema grade.

Optical coherence tomography as an adjunct tool to assess response to treatment in cerebral venous thrombosis: A prospective longitudinal study

INTRODUCTION

Papilledema, due to raised intracranial pressure (ICP) is commonly seen in cerebral venous thrombosis (CVT) and can have serious complications. This study reports the quantitative assessment of papilledema through the measurement of the Peripapillary choroidal thickness (ChT) and Peripapillary retinal nerve fiber layer thickness (RNFLT) using optical coherence tomography (OCT).

METHODS

We conducted a prospective longitudinal study of 30 subjects with CVT. Age and gender-matched healthy individuals were included as controls. In addition to history, RNFLT and ChT measurements were obtained at presentation, discharge, and follow-up two months after discharge.

RESULTS

The mean age of the patients was 32.8 ± 9.9 years. Papilledema was seen in 14 (46.66 %) patients. The peripapillary RNFLT and ChT were significantly greater in patients with CVT [RNFLT 121.5 μm (105,169) in the right eye (RE), 120 μm (103,148) in the left eye (LE); ChT 159 μm (143,171) in the RE, 155.5 μm (140,166) in the LE] as compared to controls [RNFLT 106.5 μm (102,111) in RE, 103.5 μm (98,107) in LE; ChT 130 μm (119,134) in RE, 124 μm (119,136) in LE]. There was a significant decrease in the peripapillary RNFLT and ChT in patients with papilledema at follow-up after two months in all segments in both eyes.

CONCLUSION

In patients with CVT, RNFLT, and ChT reduced significantly with treatment. OCT is potentially useful to objectively assess response to treatment in patients with CVT.

Macular exudate in idiopathic intracranial hypertension affects outer retina and visual acuity

BACKGROUND

Optical coherence tomography (OCT) is suggested as a potential tool for retinal biomarkers in idiopathic intracranial hypertension (IIH). We explored how macular exudate (ME) affects retinal structure in IIH and investigated its relationship with their clinical features.

METHODS

Patients diagnosed with IIH and matched controls were enrolled. ME detection was done on fundus photography; swept-source OCT was used to image and measure the retinal sublayer thicknesses, including the retinal nerve fibre layer, ganglion cell-inner plexiform layer (GCIPL), inner nuclear layer (INL) and outer retinal layer (ORL). IIH patients underwent lumbar puncture where intracranial pressure (ICP) was assessed.

RESULTS

195 eyes from 98 IIH patients (42 eyes had ME) and 224 eyes from 112 controls were included. IIH patients had thicker INL and ORL compared with controls (both p<0.001) while IIH eyes with ME had thicker INL and ORL thicknesses compared with eyes without ME (both p<0.05). In IIH patients, the retinal sublayer thicknesses correlated with their ICP levels, and GCIPL thickness correlated with visual acuity (VA). Furthermore, ME was associated with higher ICP, worse papilledema and lower VA (all p<0.001).

CONCLUSION

ME affects retinal thickness in IIH patients and is associated with more severe clinical features in IIH. OCT may provide biomarkers informative of clinical changes in IIH. Further longitudinal studies are needed to explore the evolution of ME and its relationship to VA and retinal structure.

Optical coherence tomography angiography analysis in patients with intracranial hypertension

INTRODUCTION

Evidence on peripapillary microvasculature in intracranial hypertension (IH) after the regression of papilledema is still scarce. The aim of this preliminary study was to determine the association between structural changes in the optic nerve and the retina and peripapillary microvasculature in patients with IIH.

METHODS

We conducted a retrospective study. The study included 39 eyes of 21 patients with IIH. Treatment for IIH and history of obesity were registered from each patient. Moreover, OCT analysis including retinal nerve fiber layer (RNFL) thickness and ganglion cell-inner plexiform layer (GCIPL) thickness, and OCTA analysis including perfusion density (PD) and flux index (FI) of the radial peripapillary capillary plexus were performed.

RESULTS

Correlation analysis revealed a high correlation between GCIPL thickness and peripapillary PD and FI (p < 0,05, r > 0,7), whereas the degree of correlation between RNFL thickness and peripapillary microvascular parameters was low (p < 0,05, r < 0,7). Patients with regressed papilledema had significantly lower GCIPL thickness and peripapillary PD than control subjects (p < 0,05).

CONCLUSION

Peripapillary microvascular measurements are highly correlated with GCIPL thickness in patients with IIH. Moreover, GCIPL thickness and peripapillary PD are significantly inferior in patients with regressed papilledema compared to control group. Thus, we suggested that peripapillary microvascular parameters may be an early indicator of optic nerve atrophy in patients with IIH.

Interocular Symmetry and Intermachine Reproducibility of Optic Disc and Macular Parameters Measured by Two Different Models of Optical Coherence Tomography

Purpose

To compare the interocular symmetry and investigate the intermachine reproducibility of optic disc and macular data measured by spectral-domain high-definition optical coherence tomography (HD-OCT) Cirrus HD-OCT 4000 and HD-OCT 5000 from healthy subjects.

Patients and Methods

Forty-three volunteers were examined with both HD-OCT 4000 and HD-OCT 5000 at the same visit. Optic nerve head (ONH) and macular data were acquired using ONH Cube 200×200 scans and macular volume cube 512×128 scans, respectively.

Results

The average age of the participants was 33 ± 8.6 years. Interocular OCT parameters of ONH and macula showed a high correlation between the right and left eyes regardless of HD-OCT models, displaying a low coefficient of variation (CV). However, the average retinal nerve fiber layer (RNFL) was thicker (96.67±11.19µm vs 95.3±10.89µm, p<0.01), and the average central subfield thickness (261.51±17.45µm vs 262.51±17.39 µm, p<0.01) and cube average thickness (283.91± 13.59µm vs 286.55±13.09µm, p<0.05) were thinner when measured by Cirrus 4000 compared to 5000. Intermachine reproducibility and reliability of RNFL and macular parameters exhibited a high intraclass correlation coefficient (ICC) (0.985) and low CV (2.4%). Ganglion cell-inner plexiform layer (GCIPL) measured by two OCT models showed similar values with an average thickness of 85 µm and had high intermachine reproducibility with high ICC (0.993) and low CV (1.2%).

Conclusion

High interocular symmetry was observed across both HD-OCT models. Intermachine reproducibility for RNFL and all macular parameters was also high. GCIPL showed minimal intermachine differences with high reproducibility and reliability. Thus, the results imply that GCIPL values measured by two Cirrus OCT models may be used interchangeably.

Exploring the utility of retinal optical coherence tomography as a biomarker for idiopathic intracranial hypertension: a systematic review

This study aimed to examine the existing literature that investigated the effectiveness of optical coherence tomography (OCT) and optical coherence tomography angiography (OCT-A) as a biomarker for idiopathic intracranial hypertension (IIH). Our search was conducted on January 17th, 2024, and included the databases, Medline, Scopus, Embase, Cochrane, Latin American and Caribbean Health Sciences Literature (LILACS), International Standard Randomized Controlled Trial Number (ISRCTN) registry, and the International Clinical Trials Registry Platform (ICTRP). Our final review included 84 articles. In 74 studies, OCT was utilized as the primary ocular imaging method, while OCT-A was employed in two studies including eight studies that utilized both modalities. Overall, the results indicated that IIH patients exhibited significant increases in retinal nerve fiber layer (RNFL) thickness, total retinal and macular thickness, optic nerve head volume, and height, optic disc diameter and area, rim area, and thickness compared to controls. A significant correlation was observed between cerebrospinal fluid (CSF) pressure and OCT parameters including RNFL thickness, total retinal thickness, macular thickness, optic nerve head volume, and optic nerve head height. Interventions aimed at lowering CSF pressure were associated with a substantial improvement in these parameters. Nevertheless, studies comparing peripapillary vessel density using OCT-A between IIH patients and controls yielded conflicting results. Our systematic review supports OCT as a powerful tool to accurately monitor retinal axonal and optic nerve head changes in patients with IIH. Future research is required to determine the utility of OCT-A in IIH.

Swelling of Atrophic Optic Discs in Idiopathic Intracranial Hypertension

BACKGROUND

Monitoring patients with idiopathic intracranial hypertension (IIH) and optic atrophy may be difficult as papilledema may not be appreciable on ophthalmoscopy. This retrospective chart review evaluated whether papilledema recurrence can be detected in this population using optical coherence tomography (OCT).

METHODS

Serial clinical assessments, ophthalmoscopy, and peripapillary OCT were reviewed in a cohort of patients with IIH and optic atrophy. Atrophy was defined as moderate if average peripapillary retinal nerve fiber layer (pRNFL) thickness was ≤80 μm and severe if average pRNFL thickness was ≤60 μm on at least 2 consecutive high-quality OCT scans. Based on the upper tolerance limit of test-retest variability, mean pRNFL elevation of ≥6 μm with subsequent decrease to baseline thickness was considered papilledema.

RESULTS

In a cohort of 165 patients with IIH, 32 eyes of 20 patients and 22 eyes of 12 patients demonstrated moderate and severe optic atrophy, respectively. Over a median follow-up of 198.5 weeks (range, 14.0-428.9), 63.3% (19 of 30) of patients had at least 1 episode of relapse, and 50.0% (15 of 30) had at least 1 episode of papilledema. There was a total of 36 relapse episodes, of which 7 occurred in patients with clinical signs and symptoms but no OCT evidence of relapse, 12 occurred in patients with OCT changes but no clinical signs and symptoms of relapse, and 17 occurred in patients with both clinical and OCT evidence to support relapse. The median percent pRNFL increase in the latter 2 groups was 13.7% (range, 7.5-111.8), and 7 eyes (13.0%) of 5 patients (16.7%) showed thickening greater than 20.0% from baseline. The rate, magnitude, and concordance of pRNFL swelling were similar between moderately vs severely atrophic eyes.

CONCLUSIONS

Papilledema recurrence can be detected in atrophic optic discs using OCT. All patients with atrophic IIH should be longitudinally monitored with pRNFL measurement. Concurrence of other relapse-suggestive features should prompt further evaluation.

The Pseudotumor Cerebri Syndrome

Pseudotumor cerebri syndrome is a syndrome of increased cerebrospinal fluid pressure without ventriculomegaly, mass lesion, or meningeal abnormality. It is either primary (idiopathic intracranial hypertension, IIH) or secondary. A secondary cause is unlikely when adhering to the diagnostic criteria. Permanent visual loss occurs if undetected or untreated, and the associated headaches may be debilitating. Fulminant disease may result in blindness despite aggressive treatment. This study addresses the diagnosis and management of IIH including new insights into the pathobiology of IIH, updates in therapeutics and causes of overdiagnosis.

Optical coherence tomography in papilledema: A probe into the intracranial pressure correlation

PURPOSE

To study the optic nerve head characteristics on optical coherence tomography (OCT) in patients with papilledema and correlate them with intracranial pressure (ICP).

METHODS

A retrospective hospital-based study of 46 eyes of 23 patients with bilateral optic disc edema secondary to increased ICP. The clinical profile and the OCT features in terms of retinal nerve fiber layer thickness (RNFL), ganglion cell inner plexiform layer (GCIPL) thickness, and enhanced depth imaging (EDI) B scan images of the optic nerve head were studied and correlated with the ICP.

RESULTS

Papilledema was secondary to idiopathic intracranial hypertension (IIH) ( n = 20), obstructive hydrocephalus ( n = 2), and communicating hydrocephalus ( n = 1). The mean ICP in 20 IIH patients was 347 mmH 2 O. The ICP and RNFL thickness in all four quadrants were found to be weakly positively correlated: superior RNFL r (38) = 0.17, P = 0.30, and nasal RNFL r (38) = 0.30, P = 0.05, inferior RNFL r (38) = 0.29, P = 0.07, and temporal RNFL, r (38) = -0.001, P = 0.99. The GCIPL layer thickness and the ICP were weakly negatively correlated in all sectors: superior (38) = -0.23, P = 0.16, superonasal, r (38) = -0.07, P = 0.67, inferonasal r (38) = -0.08, P = 0.64, inferior r (38) = -0.21, P = 0.19, inferotemporal r (38) = -0.23, P = 0.17, superotemporal, r (38) -0.21, P = 0.20. Descriptive features on the B scan, such as peripapillary hyperreflective ovoid mass-like structures and microcystic spaces, were observed most commonly with an ICP of 251-350 mmH 2 O, and the hyperreflective dots in the RNFL layer and Bruch's membrane inward denting were observed more commonly with an ICP of 351-450 mmH 2 O.

CONCLUSION

The RNFL thickness in all four quadrants had a weak positive correlation, and the GCIPL layer had a weak negative correlation with the ICP. The EDI descriptive features on OCT may vary with ICP.

The Relationship between Lumbar Puncture Opening Pressure and Retinal Nerve Fiber Layer Thickness in the Diagnosis of Idiopathic Intracranial Hypertension: Is a Lumbar Puncture Always Necessary?

OBJECTIVES

Idiopathic intracranial hypertension (IIH), is characterized by elevated intracranial pressure (ICP) without an identified cause. Today, lumbar puncture (LP) is the most common method used for diagnosis by measuring cerebrospinal fluid (CSF) pressure to reflect intracranial pressure. This invasive examination has significant disadvantages, such as complications and negative experiences for patients. Therefore, noninvasive methods for ICP measurement are desired. Optical coherence tomography (OCT) is widely used for the diagnosis and follow-up of IIH patients as it reflects papilledema. The aim of this study is to investigate the relationship between CSF pressure and OCT parameters and the ability of OCT in the diagnostic approach.

METHODS

In our study, patients who were followed up with a diagnosis of IIH with complete neuro-ophthalmological examinations, including visual acuity (VA), visual field, and OCT imaging within 24 hours before lumbar puncture, were retrospectively evaluated. CSF pressure, visual acuity LogMAR, mean deviation of visual fields, retinal nerve fiber layer (RNFL) thickness measured by OCT, and treatment protocols were obtained from our hospital data system.

RESULTS

A total of 42 eyes of 21 patients were enrolled in the study. A statistically significant positive and moderate correlation was found between CSF pressure values and average RNFL thickness ( r =0.507; P =0.001). The same relationship was demonstrated in all 4 quadrants: inferior, superior, nasal, and temporal.

CONCLUSIONS

Increased peripapillary RNFL thickness in optic nerve head OCT may be correlated with increased ICP in IIH patients. A larger number of patients are needed to better understand the correlation between OCT parameters and CSF pressure in patients with IIH.

Idiopathic intracranial hypertension in Omani adults: A tertiary center experience

BACKGROUND

To evaluate the clinical profile, risk factors, and ophthalmic diagnostic and monitoring tools in Omani patients with idiopathic intracranial hypertension (IIH) using optical coherence tomography (OCT).

METHODS

A retrospective single institutional cohort study on Omani patients with a fulfilled diagnosis of IIH from January 1, 2014, to January 1, 2020, was conducted. The data obtained from the neuro-ophthalmic clinic contained age of onset of the disease, gender of patients, body mass index (BMI), presence of other associated conditions, and medication use.

RESULTS

Our study group comprised 21 patients with IIH with an annual incidence rate of 2.8 per 100,000 population. Female-to-male ratio was 9.5:1 with a mean age of 27.24 ± 7.1. Headaches appeared to be the most prevalent symptom in 21 (100%) patients, followed by transient obscuration of vision in 9 (42.9%) patients and diplopia in 3 (14.3%) patients, and the least common symptom was pulsatile tinnitus in 2 (9.5%) patients. Increased BMI was seen in 19 (90.5%) patients and noted to be the most prevalent predisposing factor among our study group. The use of oral contraceptive pills was documented in 4 (19%) patients and 1 (4.8%) patient was noted to have polycystic ovary syndrome. All patients (100%) had a best-corrected visual acuity of 1.0 in both eyes pre- and postrecovery and 7 (33.3%) patients had an enlarged blind spot on visual field testing. All patients had papilledema on presentation and an average of 14.1 months to resolve to normal clinically and on OCT monitoring. All patients were treated with medications and only 1 (4.8%) continued to have intractable headaches that did not respond to maximum medical therapy and required surgery.

CONCLUSION

The incidence of IIH in the Omani population was found to be less than neighboring countries but comparable worldwide. OCT is considered a useful tool to confirm and document papilledema and more importantly monitor recovery.

Retinal microvascular and structural changes in intracranial hypertension patients correlate with intracranial pressure

AIMS

We aimed to evaluate the retinal microvascular and structural changes in intracranial hypertension (IH) patients compared with an age- and sex-matched control group. We also investigated the association between clinical parameters and retinal changes in IH patients.

METHODS

Intracranial hypertension patients were divided into eyes with papilledema (IH-P) and eyes without papilledema (IH-WP). IH patients underwent lumbar puncture to measure intracranial pressure (ICP); visual acuity was performed using the Snellen chart. Optical coherence tomography (OCT) was used to image and measure the retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) while OCT angiography was used to image and measure the superficial vascular complex (SVC) and deep vascular complex (DVC).

RESULTS

Intracranial hypertension patients showed reduced microvascular densities and thinner retinal thicknesses compared with the control group (all p < 0.001). Compared with the control group, IH-P showed reduced microvascular densities and thinner retinal thicknesses (all p < 0.001). IH-P showed reduced SVC density and thinner retinal thicknesses when compared with IH-WP (p = 0.008 for SVC, p = 0.025 for RNFL, and p = 0.018 for GCIPL). ICP correlated with the microvascular densities and GCIPL thickness in IH patients (p = 0.025 for GCIPL, p = 0.004 for SVC, and p = 0.002 for DVC). A significant association of ICP with SVC (p = 0.010) and DVC (p = 0.005) densities were also found in IH-P.

CONCLUSIONS

Given the observed differences in these noninvasive retinal imaging markers, further research into their clinical utility in IH is needed.

Optical coherence tomography features and correlation of functional and structural parameters in patients of idiopathic intracranial hypertension

Purpose:

To determine the correlation between functional parameters and optical coherence tomography (OCT) features in patients of idiopathic intracranial hypertension (IIH).

Methods:

A prospective observational study in early and established cases of papilledema in IIH presenting from December 2017 to February 2019. Functional parameters (visual acuity, contrast sensitivity, mean deviation, VER, and MfERG) and structural parameters (RNFL, GCL-IPL, and optic disc height) were measured at baseline and every 6 weeks for 6 months.

Results:

At baseline, average RNFL had a moderate negative correlation with mean deviation (r = −0.45; P = 0.0007) and a positive correlation with logMAR visual acuity (r = 0.18; P = 0.17). On the contrary, baseline GCL and logMAR visual acuity had a negative correlation (r = −0.4, P = 0.02). Optic disc height (ODH) had a negative correlation with visual field mean deviation (r = −0.046; P = 0.0005). At 6 months, ODH and GCL-IPL complex had a statistically significant correlation with functional parameters. However, RNFL values did not show any significant correlation with any of the functional parameters. Baseline GCL-IPL and optic disc height values had a moderate and significant correlation with final functional parameters. However, RNFL did not show any correlation with final functional parameters. Correlation between GCL-IPL thickness at 6 weeks and final functional parameters were stronger than that with baseline GCL values

Conclusion:

In the setting of severe papilledema, RNFL can misguide the prognosis. GCL-IPL can be a valuable tool for an objective evaluation of the integrity of the optic nerve in IIH and ODH may be used as an alternative or in combination with GCL-IPL in these cases.

Change in contrast sensitivity and OCT parameters in idiopathic intracranial hypertension

Background:

Deterioration in peripheral contrast sensitivity (CS) can be an indicator to detect progressive deterioration of visual function in patients with idiopathic intracranial hypertension (IIH).

Objectives:

The aim of this study was to evaluate the changes in central and peripheral CS and optical coherence tomography (OCT) parameters and in patients with IIH.

Design and Methods:

In this pilot observational study, data of 20 eyes of 10 ‘treatment-naïve’ IIH patients were analyzed. Detailed ocular examination was performed including CS assessment using both Pelli–Robson (PR) test and Spaeth–Richman Contrast Sensitivity Test (SPARCS) along with the OCT for macular and optic nerve head (ONH) parameters. A comparative analysis was done for CS and OCT parameters from baseline to a follow-up visit > 12 months (range: 18–24 months).

Results:

The study population had a female preponderance (80%, n = 8), and mean age at diagnosis was 31.9 ± 10.3 years. Mean follow-up period was 21.2 months (range: 15–24 months). At presentation, 6/6 visual acuity was noted in 75% eyes ( n = 15) while all eyes had 6/6 vision at the last follow-up. Average PR score increased from 1.96 ± 0.36 to 2.30 at the last visit (Wilcoxon test: V = 0.0, p ⩽ 0.001) while average SPARCS score (total) increased from 71.85 ± 9.10 to 77.55 ± 6.20 (Paired t-test: t = −2.3, p = 0.035). Change in SPARCS score was significant in average total score ( p = 0.035), and quadrant-wise score in superonasal ( p = 0.014), inferonasal ( p = 0.001), and inferotemporal ( p = 0.021) quadrants. Same trend in SPARCS scores was observed when eyes with and without recurrence were analyzed. Statistically significant difference in retinal nerve fiber layer (RNFL) thickness ( p = 0.007) and macular thickness (MT) in nasal quadrant ( p = 0.006) was seen between the eyes with recurrence and without recurrence.

Conclusion:

Peripheral CS showed significant difference in all eyes over time. It showed significant change in eyes with recurrence, even in the presence of intact visual acuity and preserved central CS. Changes in RNFL thickness and nasal MT could differentiate eyes which developed recurrence from normal eyes.

Idiopathic Intracranial Hypertension - Challenges and Pearls

Idiopathic intracranial hypertension (IIH) is defined as a syndrome of raised intracranial pressure with normal imaging of the brain and cerebrospinal fluid (CSF) composition. There is a rising incidence and prevalence of this disease related to the increased prevalence of obesity. It typically affects women of working age, and headache is the predominant morbidity in over 90%. The disease is also more prevalent in young males. There are many controversies and myths that surround IIH. There are currently few treatment options for IIH, management is typically medical with those experiencing progressive visual loss undergoing surgical procedures. Weight loss and venous sinus stenting are a few therapies directed at the etiology.

Idiopathic intracranial hypertension: Pathophysiology, diagnosis and management

Idiopathic intracranial hypertension (IIH) is characterized by increased intracranial pressure, manifested by papilledema and radiological findings, in the absence of an identifiable casual factor. The primary symptoms include headache, vision loss, and pulsatile tinnitus, and are recognized to have profound impacts on quality of life and visual function. IIH demonstrates a strong predilection towards obese women of reproductive age, and the population incidence is rising with the growing prevalence of obesity worldwide. The pathophysiology involves dysregulation of cerebrospinal fluid (CSF) dynamics and venous sinus pressure, and recent studies highlighting the pathogenic role of metabolic and hormonal factors have led to the identification of several pharmacological targets and development of novel therapeutic agents. The overarching treatment goals include symptomatic alleviation and prevention of permanent vision loss. The Idiopathic Intracranial Hypertension Treatment Trial, the first of its kind randomized controlled trial on IIH, provides class I evidence for treatment with weight loss and acetazolamide. In medically refractive or fulminant cases, optic nerve sheath fenestration, CSF diversion, and venous sinus stenting, have been successfully implemented. However, there are few high-quality prospective studies investigating the treatment and natural history of IIH, highlighting the compelling need for further research to determine the optimal treatment regimen.

Sonographic and ophthalmic assessment of optic nerve in patients with idiopathic intracranial hypertension: A longitudinal study

BACKGROUND

To assess the validity of neurosonological parameters (transorbital sonography (TOS)) for detection and monitoring of patients with idiopathic intracranial hypertension (IIH).

METHODS

Prospective, single-center, case-controlled study in 25 patients with IIH and 19 controls. Visual parameters of papilledema, visual acuity, computerized static threshold perimetry, fundus examination, and neurosonological parameters of papilledema/optic disc elevation (ODE), optic nerve sheath diameter (ONSD) and optic nerve diameter (OND) were recorded at baseline and only for patients with IIH again within 6 months.

RESULTS

ONSD was significantly enlarged among individuals with IIH (6.2 ± 0.73 mm) compared to controls (4.99 ± 0.54 mm; p < 0.001). Bilateral ODE was found in 36/50 eyes in patients at their initial visit and in none of the controls. Re-evaluation 6 months later showed a significant reduction of ONSD (6.0 ± 0.7 mm; p = 0.024) and ODE (0.2 (0-1) mm; p ≤0.001). Best corrected visual acuity (BCVA) and square root of lost variance (sLV) remained stable. Headache intensity (Numeric rating scale, NRS) improved significantly p < 0.001. When compared to patients with first diagnosed IIH (n = 18), the subset of patients with preexisting IIH with acute relapse (n = 7) showed persistent but reduced levels of ICP increase. They also presented significant decrease of BVCA (p = 0.01) and mean defect (MD) (p = 0.012). Re-evaluation 6 months later showed significant change in ODE in both groups.

CONCLUSIONS

Our study confirmed that TOS and ophthalmological parameters are a valuable and non-invasive method to detect and monitor elevated ICP in IIH.

Optical Coherence Tomography to Monitor Rebound Intracranial Hypertension with Increased Papilledema after Lumbar Puncture

Objective: We report that lumbar puncture (LP) with removal of cerebrospinal fluid (CSF) induced rebound intracranial hypertension with increased papilledema as monitored by optical coherence tomography (OCT). Background: Severe papilledema causes visual field loss and central vision damage if untreated. Fundoscopy is a key to diagnose papilledema, but is not sensitive enough to monitor therapeutic effects. Methods: OCT was applied to follow a 24-year-old woman with headache, visual dysfunction, severe bilateral papilledema, and elevated CSF opening pressure. She was first treated with serial LP, which led to symptom deterioration, increased CSF pressure, and increased the retinal nerve fiber layer (RNFL) thickness. She was then successfully treated with acetazolamide and furosemide. Results: OCT showed reduction of RNFL thickness directly after LP with CSF removal, accompanied with reduced CSF pressure. Increased RNFL thickness accompanied with worsened headache, visual dysfunction, and increased CSF pressure was observed on the next day after LP. Less than 24 h after start of medication, the symptoms had reversed and RNFL thickness was reduced. The patient was symptom-free 2 weeks after starting on medical treatment. Papilledema had vanished on fundoscopy 6 weeks after the therapy, and RNFL thickness was normalized at 3 months of follow-up. Conclusion: This case provides evidence that OCT is an objective and sensitive tool to monitor papilledema and its response to therapy, and thereby important to help in correct clinical decision-making.

Etiology, pathogenesis and management of idiopathic intracranial hypertension, and role of optic canal size in asymmetric papilledema: A review

Idiopathic intracranial hypertension (IIH) is characterized by raised intracranial pressure of unknown origin that primarily afflicts obese women of childbearing age. There are several treatment options, but currently there are none that are effective for the entire affected population. The lack of a universally effective treatment is related to an incomplete understanding of the etiology of the condition and the lack of a well-defined pathophysiological mechanism for the disease process. Classically, IIH has been thought of as a diagnosis of exclusion once radiographical imaging has ruled out all other causes of elevated intracranial pressure. Today, we know that imaging does capture subtle changes, and might provide keys to finally understand the pathogenesis of IIH so that a definitive treatment can be discovered or developed. Recently, advancements in radiography, optical coherence tomography, and electroretinography have shown promise for the future of IIH evaluation. A topic within IIH imaging that has recently sparked interest is the possibility that the severity of papilledema may have an association with the size of the optic canal. In this article, we also discuss the recent studies on the relationship between asymmetric papilledema and optic canal size.

Optical Coherence Tomography Revealing Ganglion Cell Loss in Idiopathic Normal Pressure Hydrocephalus

BACKGROUND

Although there may theoretically be a disturbance in the eye or the visual pathways due to abnormal cerebrospinal fluid (CSF) dynamics in idiopathic normal pressure hydrocephalus (iNPH), it has not been studied systemically. Optical coherence tomography (OCT) is a noninvasive, reproducible procedure for quantitative and qualitative analysis of retinal morphology.

METHODS

OCT was used to study the eye fundus before and after a CSF tap test in patients with iNPH compared with healthy individuals (HIs). Twelve patients with iNPH (6 females and 6 males) with a median age of 76 years (64-84 years) and 21 HIs (11 females and 10 males) with a median age of 73 years (64-79 years) were included. The patients underwent neurological, cognitive, and physiotherapeutic evaluation. Brain magnetic resonance imaging, CSF tap test via lumbar puncture, and subsequently CSF analysis were performed. OCT was performed before and after CSF removal. HIs underwent OCT once.

RESULTS

The patients had significantly reduced retinal ganglion cell layer thickness 71 μm (56-81 μm) compared with the HIs, 79.5 μm (72-90 μm) (P = 0.001), but no significant changes were observed before or after the CSF tap test. All patients improved in motor function in a 10-m walk test after the CSF tap test. The median CSF pressure was 15 and 1 cm H₂O, respectively, before and after lumbar puncture with removal of median 43.5 mL CSF.

CONCLUSIONS

This pilot study shows OCT findings that differ from HIs and implies a rational for becoming a valuable tool in the diagnosis of iNPH. Further studies are warranted to elucidate the pathology of the retina in iNPH.

Optical coherence tomography confirms shunt malfunction and recurrence of raised intracranial pressure in optic atrophy

BACKGROUND

Investigating potential cerebrospinal fluid (CSF) shunt malfunction can be a challenge. Optical coherence tomography (OCT), a non-invasive imaging technique, is used to monitor changes at the optic nerve head in papilloedema. Conventional teaching suggests that in the presence of optic atrophy the optic nerve head may not re-swell in response to a relapse in raised intracranial pressure (ICP).

METHODS

A retrospective case series of three patients who had prior CSF diversion surgery for idiopathic intracranial cranial hypertension (IIH) is presented demonstrating the benefit of non-invasive OCT imaging confirming raised ICP.

RESULTS

Recurrence of raised ICP, due to malfunctioning CSF shunt, was diagnosed in three patients requiring further surgical intervention. All re-presented acutely with headache and visual disturbances. All had a prior diagnosis of optic atrophy. In all patients, OCT peripapillary retinal nerve fibre layer qualitative image analysis and quantified progression analysis permitted easy detection of the recurrence of papilloedema.

CONCLUSION

OCT imaging supports clinical decision making in shunt malfunction, even in the presence of established optic atrophy secondary to IIH.

Retinal thinning and brain atrophy in early MS and CIS

BACKGROUND

Optical coherence tomography (OCT) could be complementary to magnetic resonance imaging (MRI) of the brain in monitoring course of multiple sclerosis (MS) and clinically isolated syndrome (CIS). Thinning of neurons in ganglion cell-inner plexiform layer (GCIPL) measured by OCT is assumed to be associated with brain atrophy.

OBJECTIVES

To evaluate association of GCIPL with brain parameters detected by quantitative MRI (qMRI) and MR-spectroscopy (MRS) in early MS and CIS.

METHODS

Seventeen newly diagnosed MS and 18 CIS patients were prospectively included. The patients were assessed at baseline as well as at 1 year follow-up by OCT, qMRI and MRS. Brain parenchymal and myelin volumes (BPV, MYV respectively) and the corresponding fractions (BPF, MYF) were measured with qMRI. Metabolites including myo-inositol (myo-Ins) were measured in the normal-appearing white matter (NAWM) using MRS. T-tests and ANOVA were used to analyze group differences, and linear regression models to evaluate association of GCIPL with BPV, MYV and myo-Ins after correlation analysis.

RESULTS

Disease activity reflected by lesions on MRI and presence of CSF oligoclonal IgG bands were more prominent in MS compared to CIS. GCIPL, BPV, MYV, BPF and MYF were reduced, while concentration of myo-Ins was increased in MS compared to CIS. Follow-up showed consistency of thinner GCIPL in MS compared to CIS. GCIPL thinning correlated with reduced BPV and MYV (P < .05 for both), but with increased myo-Ins (P < .01).

CONCLUSIONS

Significant GCIPL thinning occurs in early MS and is associated with enhanced brain inflammation and atrophy.

The prevalence of papilledema in patients with migraine: a crucial cooccurrence of migraine and idiopathic intracranial hypertension

OBJECTIVE

We aimed to investigate the prevalence of idiopathic intracranial hypertension (IIH) in patients with migraine by screening for papilledema.

MATERIALS AND METHODS

We have included all the patients with migraine who applied to our neurology clinic during December 2019 and accepted to participate in the study. The demographic and clinical characteristics including migraine subtype (episodic/chronic), headache frequency per month, and headache characteristics of all patients were interrogated. Besides, the presence of fibromyalgia (FM) and chronic fatigue syndrome (CFS) was noted. Fundus examination was performed in all of the patients and the presence of papilledema was noted.

RESULTS

Overall, 158 consecutive migraineurs were included in this study. The mean age of the group was 35.9 ± 9.9 and the female/male ratio was 134/24. Papilledema was determined in 10 (6%) patients. There was a past medical history of having IIH in one of these patients. In four of the patients, the diagnosis of IIH was newly established. Comparative analyses between episodic migraineurs and chronic migraineurs revealed that female gender was more prevalent in chronic migraineurs (p = 0.00) and the comorbidities of FM and CFS were more common in chronic migraineurs. Remarkably, papilledema was found to be more common in chronic migraineurs. The results of the logistic regression analyses revealed that obesity was the only predictor for the presence of papilledema (p = 0.014).

CONCLUSION

Our results may suggest that IIH should be kept in mind as a notable comorbidity in migraineurs, particularly in the subgroup of obese patients with chronic migraine.

Retinal Nerve Fibre Layer Thickness Increases with Decreasing Spectralis OCT Signal Strength in Normal Eyes

We sought to determine effect of signal strength on mean retinal nerve fibre layer (RNFL) using Spectralis optical coherence tomography (S-OCT). Thirty normal subjects (18 female, mean 37.9 years, range 24-61) were imaged with S-OCT using variably dense Bangerter foils to alter Q value (1 unit signal strength = 4 units Q). We found a statistically significant (p < 0.01) linear relationship (R = 0.8643) between Q and RNFL (1 unit decrease Q = 0.181 um mean RNFL increase). Unlike previous observations of Cirrus and Stratus OCT, we found RNFL thickness does not decrease with decreasing signal strength in S-OCT.

Visual evoked potentials follow-up in idiopathic intracranial hypertension

OBJECTIVE

To demonstrate the importance of visual evoked potential (VEP) in determining the severity and prognosis of the disease and in monitoring the clinical course in patients with idiopathic intracranial hypertension (IIH).

METHODS

This is a prospective cross-sectional study conducted covering the period between March 2014 and January 2015. The study included 32 patients recently diagnosed with IIH and 30 healthy volunteers. The initial VEP values of the IIH patients were compared to the VEP values of the healthy control group. Furthermore, the initial VEP values of the IIH patients were compared with their VEP values after one month of treatme RESULTS: The mean age of the IIH patients was 37.8+/-12.02 years. Of the IIH patients, 27 (84%) were females and 5 (16%) were males. There was a statistically significant association of the initial VEP values with the visual field findings (p=0.011) and visual acuity (p=0.040). Moreover, a statistically significant difference was found between the control group and IIH patients in terms of right (p less than 0.001) and left P100 values (p less than 0.001). While 18 (56%) of the initial VEPs of IIH patients were pathological, 14 (44%) of the second VEPs were pathological, and this difference was not statistically significant (p=0.125).

CONCLUSION

A relationship between the VEP P100 values and the severity of the disease was detected, while the importance of monitoring VEP values in the follow-up of IIH patients was not demonstrated.

Update on the Diagnosis and Treatment of Idiopathic Intracranial Hypertension

Advances in ophthalmic diagnostics and results of interventional clinical trials are shifting diagnosis and management of idiopathic intracranial hypertension (IIH) to be more technology- and evidence-based. In this article, the evidence supporting current diagnostic criteria, evaluation, and medical and surgical management of IIH are reviewed.

Retinal correlates of neurological disorders

Considering the retina as an extension of the brain provides a platform from which to study diseases of the nervous system. Taking advantage of the clear optical media of the eye and ever-increasing resolution of modern imaging techniques, retinal morphology can now be visualized at a cellular level in vivo. This has provided a multitude of possible biomarkers and investigative surrogates that may be used to identify, monitor and study diseases until now limited to the brain. In many neurodegenerative conditions, early diagnosis is often very challenging due to the lack of tests with high sensitivity and specificity, but, once made, opens the door to patients accessing the correct treatment that can potentially improve functional outcomes. Using retinal biomarkers in vivo as an additional diagnostic tool may help overcome the need for invasive tests and histological specimens, and offers the opportunity to longitudinally monitor individuals over time. This review aims to summarise retinal biomarkers associated with a range of neurological conditions including Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS) and prion diseases from a clinical perspective. By comparing their similarities and differences according to primary pathological processes, we hope to show how retinal correlates can aid clinical decisions, and accelerate the study of this rapidly developing area of research.