Bedside optical coherence tomography for Terson's syndrome screening in acute subarachnoid hemorrhage: a pilot study

Terson Syndrome in Patients with Aneurysmal Subarachnoid Hemorrhage: A 10-Year Single-Center Experience

BACKGROUND

Terson syndrome (TS), an intraocular hemorrhage associated with aneurysmal subarachnoid hemorrhage (aSAH), occurs in up to 46% of all patients with subarachnoid hemorrhage. Despite its high incidence, TS is underrepresented in the literature, and patients with aSAH are sometimes not systematically evaluated for the presence of TS in clinical practice. This work aims to raise awareness of TS, reevaluate previous scientific findings, describe risk factors associated with the occurrence of TS, and present our local diagnostic and treatment concept.

METHODS

All patients with aSAH treated at our institution between October 2010 and May 2020 were included in this retrospective study. The frequency of ophthalmological screening by indirect funduscopy, as well as the results, was investigated. In addition, the collection and statistical analysis of epidemiological and clinical data was performed using χ2, Kruskal-Wallis, and analysis of variance testing; multivariate regression; and receiver operating characteristic analysis. The significance level was set at p < 0.05.

RESULTS

A total of 617 patients were treated for aSAH in our institution. Of these, 367 patients (59.5%) were ophthalmologically examined for the presence of TS. The rate of TS in the examined patients was 21.3% (n = 78). Patients with TS had significantly higher Fisher and World Federation of Neurosurgical Societies (WFNS) scores (p < 0.0001). Regression analyses showed WFNS grade (p = 0.003) and the occurrence of seizures (p = 0.002) as independent predictors of TS, as did receiver operating characteristic analyses, which had a significant area under the curve of 0.66 for the combination of WFNS grade and seizures. For 12 (15.4%) patients, the TS had to be surgically treated by pars plana vitrectomy in a total of 14 eyes, which resulted in significant improvement of visual function in all patients: mean preoperative best-corrected visual acuity was 0.03 (± 0.08) versus 0.76 (± 0.21) postoperatively (p < 0.001).

CONCLUSIONS

TS is a common complication in patients with aSAH, affecting approximately one in five patients. A higher WFNS grade and the occurrence of seizures are associated with TS; therefore, screening for TS should be performed in these patients.

Terson's syndrome, the current concepts and management strategies: A review of literature

Terson's Syndrome describes intraocular hemorrhage secondary to an acutely raised intracranial pressure (ICP). Although Terson's Syndrome is common amongst patients with subarachnoid hemorrhage (SAH), it is underdiagnosed and often overlooked. This review discusses the current understanding of the etiopathogenesis, clinical features, and management of Terson's Syndrome and highlights the visual and prognostic implications to stress the importance of timely diagnosis and management. The origin of intraocular hemorrhage in Terson's Syndrome has been debated. A recognized theory suggests that an acutely raised ICP induces effusion of cerebrospinal fluid into the optic nerve sheath which dilates the retrobulbar aspect of the sheath in the orbit. Dilatation mechanically compresses the central retinal vein and retinochoroidal veins resulting in venous hypertension and rupture of thin retinal vessels. A commonly reported clinical feature is decreased visual acuity and blurred vision. These may be accompanied by symptoms of increased ICP including loss of consciousness and headache. Diagnosis is established using evidence from the clinical presentation, ophthalmoscopy, and, when required, imaging including B-mode ultrasound, CT, MRI, and fluorescein angiography. Terson's Syndrome is managed conservatively by observation for mild cases and with vitrectomy for bilateral cases and for patients whose hemorrhage has not spontaneously resolved after an observational period. Terson's Syndrome can be used as a prognostic indicator of morbidity and mortality in underlying pathology like SAH. Fundoscopy of patients with SAH, acutely raised ICP or visual disturbance with unknown etiology can help establish a timely Terson's Syndrome diagnosis. This may avoid the risk of permanent visual impairment.

[Optical coherence tomography angiography in intensive care medicine : A new field of application?]

BACKGROUND

Many critically ill patients show a disturbance of the microcirculation, which is not yet regularly examined in the clinical routine; however, for treatment decisions and estimation of the prognosis it would be important to obtain detailed information about the microcirculation in critically ill patients. Optical coherence tomography angiography (OCTA) is a non-invasive, contact-free technique, which enables visualization of the blood flow in the retinal microcirculation within a few seconds. Therefore, it may have the potential to diagnose microcirculation disorders in critically ill patients.

OBJECTIVE

The aims of the study were to assess the importance of the microcirculation in intensive care medicine, a comparison of the methods of video microscopy and OCTA and analysis of preclinical and clinical data on the use of OCTA in intensive care medicine.

MATERIAL AND METHODS

A selective literature review and data analysis were carried out.

RESULTS

A direct visualization of the microcirculation has been possible for many years with the technique of video microscopy but this has not become established in the clinical routine due to the susceptibility to interferences and a time-consuming manual analysis. The OCTA is a non-invasive and contact-free method for the visualization of retinal blood flow. First preclinical data in septic and hemorrhagic shock show good results of OCTA for analysis of the microcirculation.

CONCLUSION

The non-invasive technique of OCTA is a promising measurement method to enable bedside analysis of the microcirculation in critically ill paients in the future; however, some technical limitations must still be overcome.