What Do You Mean by Terson Syndrome?
Terson syndrome is characterized by rupture or hemorrhage of the blood vessels inside the eyes following brain trauma. The rupture of the blood vessels can occur in different regions of the eyes, including the vitreous humor and the retina.
How Ordinary Is Terson Syndrome of the Eye?
Terson syndrome is more common in adults than in children. However, a few cases involving children as young as seven months old have also been reported. It can affect either one or both the eyes. It is more commonly associated with subarachnoid hemorrhage (SAH) and least common with Traumatic Brain Injury.
What Are the Relevant Ocular Structures That Are Affected by Terson Syndrome?
Terson syndrome mainly affects the blood vessels of the eyes.
The blood vessels involved are:
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Choroidal vasculature.
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Retinal vasculature.
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Subarachnoid space surrounding the optic nerve.
Who Is at More Risk of Getting Terson Syndrome?
Patients who are at a higher risk of contracting the condition are:
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Patients with more significant impairment of consciousness.
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Patients with prolonged episodes of unconsciousness.
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Stronger associations are seen in patients with anteriorly located aneurysms (ballooning of the arteries).
What Are the Possible Reasons Behind Terson Syndrome?
Terson syndrome is associated with conditions that raise the pressure inside the brain as in raised intracranial pressure. The conditions that are responsible for increasing the pressure inside the brain are:
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Carotid artery occlusion.
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Cortical venous sinus thrombosis.
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Epidural saline injection.
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Intra arterial angiography.
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Iatrogenic bleeding.
What Are the Different Forms of Hemorrhages Associated With Terson Syndrome?
The hemorrhages that are most frequently seen in patients with Terson syndrome are:
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Sub-internal limiting membrane hemorrhage. It is a rare condition that results in permanent vision loss.
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Subretinal hemorrhage.
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Subhyaloid hemorrhage. It is a blood collection inside the space at the posterior-most part of the retina and vitreous.
How Is the Development of Terson Syndrome Explained?
The primary process that happens in Terson syndrome is the rupture of the tiny capillaries and the central retinal vein supplying the retina. The rupture of the blood vessels is augmented by various processes, which increases the intracranial pressure. An increase in the pressure inside the brain leads to the flow or outflow of cerebrospinal fluid (CSF) towards the optic nerve sheath. This ultimately results in manual compression of the eyes' arteries, veins, and capillaries.
What Are the Clinical Signs and Symptoms of Terson Syndrome?
The various clinical presentations of Terson syndrome are:
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The dome-shaped hemorrhagic area inside the macula. The macula is the posterior-most part of the retina of the eyes.
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The hemorrhage appears as a double ring; the outer ring represents the subhyaloid bleeding, and the inner ring represents the sub-inner-limiting membrane hemorrhage.
How Are Patients With Terson Syndrome Diagnosed?
Patients with Terson syndrome are diagnosed by clinical examination and imaging. However, visual imaging becomes difficult in patients with neurological symptoms and cognitive impairment.
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Clinical evaluation of the patient with Terson syndrome shows high grades of Hunt and Hesse grade, low Glasgow coma scale, and high levels of Fisher grade.
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Loss of the red reflex is seen in twenty percent of the eyes with Terson syndrome.
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Fundoscopic examination remains the gold standard for diagnosis of the syndrome.
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B-scans are used to confirm vitreous hemorrhage when nothing is visible in the fundoscopic examination.
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Computed tomography or CT is also possible to identify Terson syndrome in patients with vitreous hemorrhage, retinal hyperdensities, and retinal nodularities.
Both B-scans and CT are viable options for screening Terson syndrome.
How Does the Condition Appear in Various Imaging?
The features of the Terson syndrome in various imaging are:
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In ultrasonography, the degenerating or the damaged blood cells appear as hypoechoic areas.
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CT shows the presence of retinal hyperdensity and crescentic hyperdensity.
Why Is Terson Syndrome Often Underdiagnosed?
Despite the high incidence of the syndrome, it remains underdiagnosed. The plausible causes for the underdiagnosis of the condition are:
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Patients with the syndrome also suffer from neurological complications and cannot verbalize their problems.
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In patients with severe neurological symptoms, the visual examination is not conducted until the symptoms become severe.
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Ophthalmologist referral of the patients with condition is often delayed.
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Unawareness about the condition among primary care physicians.
What Are the Complications of Terson Syndrome?
Terson syndrome can are associated with multiple complications like:
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The epiretinal membrane formation is the most common sequelae of Terson syndrome.
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Formation of retinal folds.
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Retinal detachment.
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Ghost cell glaucoma.
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Vitreoretinopathy.
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Periretinal fibrosis.
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Amblyopia can occur in cases of bilateral eye involvement or in very young children.
What Are the Treatment Measures Adopted to Manage Patients With Terson Syndrome?
Terson syndrome cases caused by intraocular hemorrhages are resolved spontaneously. However, vitreous hemorrhages do not resolve by themselves. Terson syndrome can be managed by conservative management and also by vitrectomy surgery.
- Vitrectomy is considered in patients with severe vision loss and bilateral eye involvement. There is no consensus regarding the timing of vitrectomy procedures; however, it is generally performed after three months. Vitrectomy is a surgery to correct various pathologies related to the retina and vitreous humor. Gas injection may also be conducted as a part of the vitrectomy procedure. Recalcitrant or recurrent cases of Terson syndrome are best managed with gas or intravitreal injections of tPA (tissue plasminogen activator).
- Pars plana vitrectomy (PPV), which is a type of vitrectomy procedure, may provide a good outcome. It is a commonly used surgical procedure that helps access the retina's posterior part. PPV in Terson syndrome allows for visual acuity, especially in patients below the age of forty-five.
- For minor cases of Terson syndrome, a laser hyaloidotomy using a gonio-3 mirror may be a chosen treatment modality.
- Apart from the ocular treatment, these patients also warrant neurological management.
What is the prognosis of Terson syndrome?
Patients suffering from Terson syndrome usually have transient vision loss. The neurological and overall survival outcomes of these patients are poor.
Conclusion
Terson syndrome is a commonly occurring condition in patients who already suffer from brain injury or other neurological conditions. It is more frequently seen in patients with subarachnoid hemorrhages and who suffer from several episodes of unconsciousness. Despite the high incidence of Terson syndrome, it remains underdiagnosed due to a lack of awareness and the inability of the patient to verbalize their problem. Terson syndrome is best treated with vitrectomy. Visual loss associated with the condition is temporary.
