Transorbital sonography: A non-invasive bedside screening tool for detection of pseudotumor cerebri syndrome

BACKGROUND

Our objective was to assess optic nerve sheath diameter (a marker of elevated intracranial pressure) and optic disc elevation (a marker of papilledema) in pseudotumor cerebri syndrome using transorbital sonography.

METHODS

The study was a prospective case-control study. We included patients with new-onset pseudotumor cerebri syndrome and matched healthy controls. All had fundoscopy, lumbar puncture with opening pressure and transorbital sonography. Sonography was assessed by a blinded observer.

RESULTS

We evaluated 45 patients and included 23 cases. We recruited 35 controls. Optic nerve sheath diameter was larger in pseudotumor cerebri syndrome compared to controls (6.3 ± 0.9 mm versus 5.0 ± 0.5 mm, p < 0.001) and so was optic disc elevation (0.9 ± 0.4 mm versus 0.4 ± 0.1 mm, p < 0.001). The optimal cut-off point for optic nerve sheath diameter was 6 mm with a sensitivity of 74% for prediction of pseudotumor cerebri syndrome and 68% for prediction of elevated opening pressure. Specificity was 94%. The optimal cut-off point for optic disc elevation was 0.6 mm. Sensitivity was 100% and specificity 83% for prediction of pseudotumor cerebri syndrome.

CONCLUSION

Optic disc elevation and optic nerve sheath diameter are increased in new-onset pseudotumor cerebri syndrome. Optic disc elevation achieved high specificity and excellent sensitivity for diagnosis of pseudotumor cerebri syndrome. Transorbital sonography (TOS) is a potential, non-invasive screening tool for pseudotumor cerebri syndrome in headache clinics.

Variability of Retinal Vessel Tortuosity Measurements Using a Semiautomated Method Applied to Fundus Images in Subjects With Papilledema

Purpose

To develop methods to quantitatively measure retinal vessel tortuosity from fundus images acquired in subjects with papilledema and assess sources of variability in these measurements.

Methods

Digital fundus images from 30 eyes of subjects with untreated idiopathic intracranial hypertension and papilledema were analyzed. Retinal vein and artery tortuosities for three to four vessels of each type were measured in a region of interest 1.8 to 2.7 mm from the center of the optic nerve head. Measurements were averaged to generate a venous tortuosity index (VTI) and arterial tortuosity index (ATI) for each eye. One image of each eye was analyzed two times by the same rater. Two images of each eye, differing by focal depth, were analyzed by the same rater. Correlations between VTI and ATI for the same image and different images were calculated.

Results

Intrarater Pearson correlations (r) were 0.8 (95% confidence interval [CI], 0.59–0.9) and 0.90 (95% CI, 0.73–0.96) for VTI and ATI, respectively, with one outlier removed. Interimage r values were 0.72 (95% CI, 0.48–0.87) and 0.96 (95% CI, 0.89–0.99) for VTI and ATI, respectively, with one outlier removed. The intraclass correlation coefficients for agreement and consistency were similar, suggesting that the discrepancy between measurements was due to residual random error.

Conclusions

The finding of similar intrarater and interimage variability suggests that intrarater variability may be a more dominant source than physiology and image acquisition.

Translational Relevance

Standardizing rater procedures and averaging multiple measuring sessions are strategies to reduce variability and improve reliability of detecting retinal vessel tortuosity changes in images of eyes with papilledema.

Advances in retina imaging as potential biomarkers for early diagnosis of Alzheimer's disease

As the most common form of dementia, Alzheimer’s disease (AD) is characterized by progressive cognitive impairments and constitutes a major social burden. Currently, the invasiveness and high costs of tests have limited the early detection and intervention of the disease. As a unique window of the brain, retinal changes can reflect the pathology of the brain. In this review, we summarize current understanding of retinal structures in AD, mild cognitive impairment (MCI) and preclinical AD, focusing on neurodegeneration and microvascular changes measured using optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) technologies. The literature suggests that the impairment of retinal microvascular network and neural microstructure exists in AD, MCI and even preclinical AD. These findings provide valuable insights into a better understanding of disease pathogenesis and demonstrate that retinal changes are potential biomarkers for early diagnosis of AD and monitoring of disease progression.

Retinal hypoxia after experimental subarachnoid hemorrhage

BACKGROUND AND PURPOSE

The patients who survive subarachnoid hemorrhage (SAH) often have long-term neurological complications. There are no reports about the pathological change of retina after SAH.

METHODS

An experimental model of SAH was established by injecting autologous blood into the prechiasmatic cistern of Sprague-Dawley rats. Hematoxylin and eosin (HE) staining was performed to show the alternation of morphology in retina after SAH. To detect the retinal new vessels (NVs), CD31 was labelled by immunofluorescence and immunohistochemistry. The time-course expressions of vascular endothelial growth factor (VEGF)-A and hypoxia-inducible factor-1α (HIF-1 α) was also revealed by Western blot analysis.

RESULTS

A clear reduction of retinal ganglion cells (RGCs) was noticed after SAH. The immunofluorescence and immunohistochemical staining of CD31 reveals a large number of NVs in RGC layer after SAH compared with the normal controls. The level of VEGF-A in the retina after SAH was increased and peaked at 12h and 14 d. The expression of HIF-1α in the retina increased as early as 3 h after SAH, reached a peak at 12 h after SAH.

CONCLUSIONS

The results showed that SAH induced the retina hypoxia resulting in the reduction of RGCs, increase of NVs and activation of NVs related HIF-1α/VEGF-A pathway.

Retinal vessel diameter changes after 6 months of treatment in the Idiopathic Intracranial Hypertension Treatment Trial

BACKGROUND/AIMS

Prior studies support an association between increased retinal venule diameter and elevated intracranial pressure (ICP). The purpose of this study was to test the hypothesis that retinal venule diameters decrease in association with long-term therapy for high ICP in subjects with idiopathic intracranial hypertension (IIH).

METHODS

This is a retrospective analysis of multicentre randomised controlled trial data. Standardised procedures were used to measure area of optic nerve head elevation (ONHA) and diameters of 4 arterioles and 4 venules 2.7 mm from the optic disc centre on fundus photos collected at baseline and after 6 months of randomised treatment with placebo+diet or acetazolamide+diet in subjects participating in the IIH Treatment Trial (IIHTT) (n=115). Change in arteriole (Da) and venule (Dv) diameters from baseline to 6 months was studied as a function of IIH, haemodynamic and demographic variables.

RESULTS

Dv decreased following 6 months of therapy (8.1 µm, 5.9%, p<0.0005) but Da did not change. Dv change was associated with ONHA change (p<0.0005, r=0.47) and this association persisted in multiple variable models.

CONCLUSIONS

Retinal venule diameter decreased, and arteriole diameter did not change in association with treatment for elevated ICP with a weight loss intervention and placebo or acetazolamide in IIHTT participants. Further study is needed to determine how retinal vessel measurements can be combined with other clinical observations to inform disease management.

Optic disk hemorrhage in health and disease

Optic disk hemorrhage occurs in all age groups from neonates to the elderly. Optic disk hemorrhage is best known for its association with visual field loss and progression in patients with glaucoma; however, it may occur in conjunction with other ocular or systemic conditions as well as in healthy individuals. It may also be the first sign of a sight-threatening condition. Variations in the shape, location, and size of the optic disk hemorrhage, as well as associated ocular and systemic signs or symptoms, may help determine the underlying pathology. We address the epidemiology, demographics, pathophysiology, clinical presentations and implications, differential diagnoses, and management of eyes with optic disk hemorrhage in diseased and healthy subjects.

Multilayered optic disc hemorrhages in adolescents

PURPOSE

To describe the clinical characteristics of multilayered optic disc hemorrhages, which are defined as subretinal, superficial retinal, and subhyaloid or vitreous hemorrhages in adolescents.

METHODS

Case records of adolescents with acute multilayered optic disc hemorrhages were identified and evaluated retrospectively from 1994 to 2012. The appearance of the hemorrhages including the size, location, extension, and disc anatomy was recorded. Fluorescein angiography, visual field examination, and spectral-domain optical coherence tomography were performed in select cases.

RESULTS

Nine boys and 7 girls were included, with a mean age of 15.0 ± 2.6 years. No precipitating factor, such as involuntary Valsalva maneuver, was identified in the majority of patients (93.75%). All eyes were myopic with an average refraction of -4.64 ± 1.88 diopters. Fifteen (93.75%) of the affected optic discs were crowded and tilted with small cups. Peripapillary subretinal hemorrhages were all crescent in shape and located at the nasal disc. Eight (50%) eyes had marked subretinal blood extension exceeding 1 disc diameter away from the disc edge. Superficial flame hemorrhages were predominantly located in the superotemporal part of the disc. Spectral-domain optical coherence tomography of the disc showed vitreopapillary traction and obvious subretinal hemorrhage with increased thickness. All multilayered optic disc hemorrhages resolved spontaneously.

CONCLUSIONS

Multilayered optic disc hemorrhages in adolescents more commonly affect myopic eyes with crowded and tilted discs. The visual outcome is excellent.

Early Intraocular Complications of Subarachnoid Haemorrhage after Aneurysm Rupture

The aim of this study was to identify factors predisposing for early intraocular complications of aneurysmal subarachnoid haemorrhage (SAH). The authors analysed 96 selected cases of aneurysmal SAH. Forty patients (42%) demonstrated abnormal fundus findings, including disc swelling (13.5%), retinal haemorrhages (23%), and vitreous haemorrhage (5%). The incidence of intraocular pathologies was significantly higher in patients who lost consciousness at the onset of SAH, were admitted with high scores of the Hunt-Hess and Fisher scales and low score of the Glasgow Coma Scale, as well as in those with arterial hypertension, more sizable aneurysm, and older.

Comparison of CT and clinical findings of Terson's syndrome in 121 patients: a 1-year prospective study

Object

Terson's syndrome (TS) is a vitreous hemorrhage in association with subarachnoid hemorrhage (SAH). Its diagnosis is often delayed, which may result in vision loss secondary to treatable conditions. Methods to hasten early diagnosis and consequent ophthalmic referral are desirable. The aims of this study were 1) to assess the specificity and sensitivity of conventional head CT for diagnosing TS in patients with aneurysmal SAH (aSAH); and 2) to determine the incidence of TS and its association with age, sex, aSAH severity, and overall mortality.

Methods

Patients admitted to Helsinki University Central Hospital who underwent surgery or endovascular treatment for a ruptured intracranial aneurysm during 2011 were participants in this prospective study. They underwent serial dilated fundoscopic examinations during a 6-month period. Two radiologists independently reviewed ocular findings suggestive of TS on conventional CT head scans obtained in all patients as a routine diagnostic procedure. Associations between TS and relevant clinical, radiological, and demographic data were analyzed with uni- and multivariate logistic regression.

Results

Of 121 participants, 13 (11%) presented with TS, and another 22 (18%) with intraretinal hemorrhages. For reviewing CT head scans, the overall observed agreement between the 2 raters was 96% (116 of 121 cases), with a substantial κ of 0.69 (95% CI 0.56–0.82). The sensitivity of the CT findings for TS was 42%, and the specificity was 97%. Associations of the World Federation of Neurosurgical Societies (WFNS) and Hunt and Hess grades on admission, the presence of intracerebral hemorrhage, female sex, and aneurysm length with TS were all statistically significant. Logistic regression demonstrated that sex and WFNS grade were independently associated with TS and provided the best fit to the data.

Conclusions

Routinely looking for TS findings in CT head scans may prove valuable in clinical practice. Terson's syndrome is associated with female sex and poor clinical condition on admission.

Late ophthalmological assessment of patients with subarachnoid hemorrhage and clipping of cerebral aneurysm

PURPOSE

To estimate prospectively late ocular manifestations in patients after aneurysmal subarachnoid hemorrhage (SAH) treated with aneurysm clipping.

METHODS

Forty-six patients (12 men and 34 women), 23-69 years of age, were included in this study. A conventional ophthalmological examination, visual evoked potentials (VEPs), and static perimetry were performed on all patients. The mean interval between the onset of SAH and the aforementioned examination was 1.9 ± 1.3 years (range 0.5-5 years). The following were compared between patients with affected and non-affected visual fields as well as between those with normal and abnormal VEPs: sex, age, time from SAH to surgery, Hunt and Hess scale, Glasgow Coma Scale, Glasgow Outcome Scale, grading of SAH according to the Fisher scale, and the size and site of aneurysm.

RESULTS

Visual field defects were found in 23 patients (50%). In all of these patients, both eyes were affected. The most frequent type of visual field defects were: constricted field (47.8%), multiple peripheral foci (26.1%), and superior field defect (17.4%). There was no significant relationship between the analyzed factors and the occurrence of visual field defects, although statistical significance was almost observed in respect to the Fisher scale (p = 0.055). Deterioration in VEPs was observed in nine patients (19.6%). In the group of patients with abnormal VEPs, the time from onset of SAH to surgery was 2.6 ± 1.8 days, whereas in the group of patients with normal VEPs this time amounted to 6.4 ± 2.4 days (p = 0.02). In patients with no changes in VEPs, the mean Fisher score was significantly higher than in the group with abnormal VEPs (2.8 ± 0.6 vs 2.0 ± 0.4 respectively, p = 0.04).

CONCLUSION

Visual field defects and VEP deterioration are frequent late ocular manifestations of SAH treated with aneurysm clipping. Damage to the visual pathway correlates with the severity of SAH and timing of aneurysmal surgery.