Commotio Retinae Symptoms, Causes, Prognosis, Treatment

Commotio Retinae, also known as Berlin's Edema, is a grayish-white discoloration of the retina that occurs after physical trauma and is caused by the rupture of the outer segment photoreceptor layer. 

Rudolph Berlin, a German physician, was the first person to identify commotio retinae or Berlin's edema in the year 1873. Rudolph Berlin defined it as a temporary grey-white opacification of the macular or peripheral retina that occurred after a forceful trauma to the eye.

Commotio retinae can affect any portion of the retina and is sometimes associated with choroidal rupture or retinal hemorrhage. Central vision is impaired by macular edema, but when edema subsides, vision typically returns to normal. Retinal scarring with pigment dispersion may occur following an acute edema episode. Depending on whether or not the macula is affected, the patient may experience a sudden decrease in their vision or have normal vision. If it affects the fovea centralis, it may result in a loss of vision that is irreversible.

Symptoms

The majority of commotio retinae patients are asymptomatic, however, they may also experience blurred vision, visual loss, and a central or paracentral scotoma. Furthermore, secondary trauma-related symptoms could be seen in the anterior or posterior section. These include 

• orbital fracture, globe rupture, 
• choroidal rupture, 
• iridodialysis etc.

In order to check for additional traumatic sequelae, the initial eye exam should be thoroughly undertaken.

Funduscopic examination is used to make a clinical diagnosis of commotio retinae. The characteristic sign is whitening or opacification of the retina, which often clears itself within 4 to 7 days in clinical settings. The most prevalent location for extramacular commotio retinae is in the inferotemporal to the temporal region. Commotio can be distinguished by the fact that the blood vessels are not disrupted.

Causes

Commotio retinae is the outcome of retinal damage induced by pressure waves generated by blunt trauma to the eye. Retinal hemorrhage or choroidal rupture may also be present. In the aftermath of an acute attack of edema, the retina may suffer from scarring and dispersion of pigment. With macular commotio retinae, your central vision gets worse. When the swelling goes away, the vision usually gets better, unless a macular hole forms or the foveal retinal pigment epithelium is damaged.

Prognosis

The majority of patients heal on their own, but those who have suffered more severe injuries may continue to have diminished vision or paracentral scotoma, which can cause visual impairment.

Although some recovery may last for up to six weeks, the majority of cases are resolved within four weeks following the injury. Patients who have macular region involvement have a bad prognosis.

Due to damage to the fovea and a higher likelihood of developing a macular hole or irreversible RPE atrophy as a secondary consequence, patients with commotio retinae affecting macula have a worse prognosis. 

Treatment

For commotio retinae, there is no established medical therapy. Within the first few days to weeks after the trauma, the patient should be thoroughly monitored to track the emergence of any complications and their management.

Intravenous steroids can be used in cases that don't settle on their own. This may minimize retinal edema and contribute to an improvement in vision.

Some in-vitro trial results support the theory that caspase activation causes photoreceptor death, and intravitreal injections of biologic caspase inhibitors may appear to be a successful therapy for people with significant commotio retinae.