Detection of nerve fiber atrophy in apparently effectively treated papilledema in idiopathic intracranial hypertension

Evaulating peripapillary vessel density ın regressed papilledema ın ıdiopathic ıntracranial hypertension patients

PURPOSE

To evaluate the retinal nerve fiber layer (RNFL) thickness, the ganglion cell complex (GCC) and vessel density of the radial peripapillary capillary (RPC) plexus of eyes with regressed papilledema in idiopathic intracranial hypertension (IIH) patients using optical coherence tomography angiography (OCT-A) and comparing the results with healthy controls.

MATERIALS AND METHODS

Fifty-one eyes of 31 patients diagnosed with IIH and 52 eyes of 52 healthy subjects were enrolled in this study. All patients underwent a complete ophthalmological examination and a 4.5 × 4.5 mm peripapillary OCT-A scanning. The quantitative results of the peripapillary RNFL and GCC thicknesses and vessel density of the RPC were analyzed.

RESULTS

The vessel density in the inferior, superior nasal, and inferior nasal sectors of the patients with IIH significantly exceeded the vessel density of the healthy controls (P = 0.008, P = 0.008, and P = 0.000, respectively). The RNFL and GCC thickness measurements were comparable in both groups.

CONCLUSIONS

Patients with IIH show vascular abnormalities in the inferior nasal region, which can be detected with OCT-A. As a noninvasive imaging modality, OCT-A could provide a new perspective for understanding the pathophysiology of IIH and could also be useful in the follow-up of these patients.

Incidental idiopathic intracranial hypertension

Objective: Idiopathic intracranial hypertension (IIH) is a neuro-ophthalmological syndrome of unknown cause that can be vision-threatening, so an early diagnosis is crucial.

Case report: We reported a case of a 68-year-old asymptomatic male referred with a cataract in his right eye (OD). Best-corrected visual acuity (BCVA) was 70 letters (20/ 40) in the OD and 85 letters (20/ 20) in the left eye (OS). Ophthalmological examination revealed a significant nuclear cataract in the OD that explained the visual acuity. Fundus imaging showed a faint nasal margin elevation of the optic disc of both eyes (OU). Optical coherence tomography (OCT) revealed a sectorial retinal nerve fiber layer (RNFL) atrophy in the inferior quadrant in the OS. Nevertheless, visual field (VF) did not demonstrate defects. Neuroimaging was normal and examination of CSF revealed an opening pressure of 500 mmH2O. A diagnosis of IIH was confirmed and acetazolamide 250 mg twice daily was recommended. After 12 months of follow-up, RNFL thickness remained stable and VF did not confirm defects.

Conclusion: A routine eye examination was the onset of IIH in our case. Thus, the ophthalmologist played a crucial role in the early diagnosis of this syndrome. Papilledema is usually a key criterion for IIH, so after its detection, exclusion diagnosis and treatment should be initiated in order to avoid permanent visual loss.

Management of the regression of papilledema with regional axon loss in idiopathic intracranial hypertension patients

PURPOSE

To use optic coherence tomography (OCT) to evaluate idiopathic intracranial hypertension (IIH) patients with subclinical segmental optic atrophy despite being under apparently effective treatment.

METHODS

IIH patients underwent an OCT examination including the peripapillary retina never fiber layer (RNFL) thickness, ganglion cell complex (GCC) thickness, focal loss volume (FLV) and global loss volume (GLV) of the GCC, and total macular thickness measurements at presentation and at 3, 6, 9, and 12 months after the diagnosis. The obtained data were compared with healthy subjects. Subjects with and without subclinical segmental atrophy at the 12th month were compared according to the demographics, clinical findings, and the OCT parameters recorded at the beginning of the disease.

RESULTS

Both eyes of 56 patients with papilledema due to IIH and 50 age- and sex-matched control subjects were included in this prospective case-control study. Regression of papilledema with regional axon loss on the peripapillary RNFL thickness map was found in 37 (33%) eyes in the IIH group. IIH patients with segmental atrophy had the following characteristics when compared to those without segmental atrophy at the beginning of the disease: higher CSF opening pressure, higher grade of papilledema, thicker mean peripapillary RNFL thickness, thinner GCC layer, greater FLV and GLV loss, and severe visual field loss.

CONCLUSIONS

Axonal loss occurred in the patients despite apparent treatment. It would be appropriate to follow-up with aggressive medical treatment those patients who present with the following characteristics: higher CSF opening pressure, higher grade of papilledema, thicker mean peripapillary RNFL thickness, and thinner GCC.

Optical coherence tomography in papilledema: what am I missing?

BACKGROUND

Grading of papilledema severity is subjective and based on monocular fundus features of the optic nerve. Interobserver agreement on grading the severity of papilledema is poor among expert observers, even using well-defined criteria such as the Frisen scale, which is a non-continuous ordinal scale of grading. Furthermore, non-expert clinicians often find it difficult to properly view and interpret features of the optic nerve using ophthalmoscopy, which can lead to failure to diagnose papilledema in non-ophthalmologic care settings. This may delay treatment, which can result in vision loss. Distinguishing papilledema from pseudopapilledema can also be difficult when surface drusen are not easily identified. Once papilledema is diagnosed, it is often difficult to determine whether a reduction in optic nerve edema is due solely to improvement in the status of the nerve or whether this represents concomitant loss of axons and viable retinal ganglion cells, leading to a poor visual outcome. Timely advancement of treatment would occur if loss of neurons could be diagnosed at an earlier stage of evaluation while optic disc edema is still present. This review will critically assess the role of optical coherence tomography (OCT) in solving these problems by providing an advanced imaging approach for diagnosis of papilledema and evaluating its severity on a continuous scale and evaluating the causes of visual loss in the setting of a swollen nerve.

METHODS ACQUISITION

The published literature (PubMed) was reviewed from 2000 to 2014 on the use of OCT for diagnosing papilledema, differentiating it from pseudopapilledema, providing a continuous scale of its severity and in evaluating causes of visual loss.

RESULTS

Recent evidence shows that OCT analysis of the retinal nerve fiber layer and retinal ganglion cell layer in papilledema can be associated with misleading artifacts due to layer segmentation failures. Newer 3D algorithms using neighboring locations help to overcome these problems. Disc volume appears to be a promising continuous measure of papilledema that is robust and has less associated artifacts. Buried optic disc drusen can be identified using enhanced depth OCT imaging, but recent studies have shown poor ability to differentiate papilledema from pseudopapilledema using OCT when the degree of disc evaluation is similar. Analysis of the retinal ganglion cell layer shows promise of early detection of vision loss due to neuronal injury. Subretinal fluid is easily identified with OCT and can help to identify a potentially reversible component of vision loss. Newer OCT imaging methods will allow the definition of capillaries and flow within them in and around the optic nerve head.

CONCLUSIONS

Currently, the most useful OCT derived features relevant to papilledema are disc volume, subretinal fluid, buried disc drusen, and thickness of the retinal ganglion cell layer.

Macular thickness measurements with frequency domain-OCT for quantification of axonal loss in chronic papilledema from pseudotumor cerebri syndrome

PURPOSE

To evaluate the ability of frequency domain-optical coherence tomography (FD-OCT)-measured macular thickness parameters to differentiate between eyes with resolved chronic papilledema and healthy eyes and to evaluate the correlation between FD-OCT measures and visual field (VF) loss on standard automated perimetry (SAP).

METHODS

Fifty-two eyes from 29 patients suffering from pseudotumor cerebri syndrome (PTC) and 62 eyes from 31 normal controls underwent FD-OCT scanning and ophthalmic evaluation including VF with SAP. All patients had previously been submitted to treatment of PTC and had clinically resolved papilledema and stable VF for at least 6 months before the study. Macular and peripapillary retinal nerve fiber layer (RNFL) thickness measurements were determined for both groups. Comparisons were made using Generalized Estimated Equations. Correlations between FD-OCT and VF measurements were verified.

RESULTS

In eyes with resolved papilledema, the macular thickness parameters corresponding to the inner and outer superior, temporal, inferior and nasal segments, average macular thickness and most RNFL thickness measurements were significantly reduced when compared with controls. The discrimination ability was similar for macular thickness measurements and RNFL thickness measurements. Both sets of OCT measurements correlated well with VF sensitivity loss.

CONCLUSIONS

Eyes with resolved chronic papilledema show a significant reduction in macular thickness, which is well correlated with the severity of VF loss. Macular thickness measurements can potentially be used to estimate and monitor the amount of ganglion cell loss in eyes with papilledema from patients with PTC.

Idiopathic intracranial hypertension is not benign: a long-term outcome study

Idiopathic intracranial hypertension (IIH) primarily affects young obese females, and potentially causes visual loss and severe headache. The aim of this experiment is to examine relapse rate and long-term outcome in IIH patients. The methods involved in this experiment include a prospective controlled study of 18 newly diagnosed IIH patients followed for a mean observation period of 21.1 (±8.0) months. Treatment regime included diuretics, dietary recommendations and check-up visits at a dietician. Baseline and follow-up included neurological examination, detailed headache history and comprehensive neuro-ophthalmological examination, including fundus photography, Humphrey visual fields, and measurement of the retinal thickness (RT) and retinal nerve fiber layers (RNFL) by optical coherence tomography (OCT). Relapse was defined as recurrence of either: (1) papilledema or (2) symptoms and demonstrated raised ICP. The result of this experiment is that relapse was found in 28%. Visual function improved from baseline to follow-up and was generally favorable. In patients without relapse of papilledema RT and RNFL were significantly thinner than in healthy controls (p = 0.003 and 0.02), although atrophy was clinically detectable in only one patient. Headache was still present in 67% of the patients at follow-up. Headache was heterogenic and unrelated to relapse. After an initial reduction, weight increased again in the relapse group compared to reduced weight in the non-relapse group (p = 0.013). Thus, the conclusions drawn are that headache was persistent, difficult to classify, and equally represented in relapse and non-relapse patients. Headache was thus a poor marker of active disease. Relapse rate was high and clinically undetectable optic disc atrophy was discovered in apparently well treated IIH patients.