Berlin's Edema or
Commotio retinae is a contrecoup injury to the retina. It can occur centrally
or peripherally, and when it involves the macula, it is called Berlin's edem.
The retina appears normal on examination although the patient may complain of
decreased vision. The affected area becomes white and opaque usually
hours after the trauma . On careful examination, most of the opaqueness
and whitening is in the outer retina and the blood vessels are clearly
seen. . On fluorescein angiography, the opaque retina blocks background
choroidal fluorescence, with minimal leakage usually.
Berlin's "edema" is not a true edema. Swelling and disorganization of
the outer retinal layers causes the opaqueness and there is no
The visual acuity in commotio retinae varies from 20/20 to 20/400 and does not
always correlate with the degree of retinal opacification. There is no known
treatment. Prognosis is usually excellent except in cases with associated
subfoveolar choroidal rupture and /or subfoveolar hemorrhage. Poor outcome
is also expected in cases with severe retinal pigment epithelial damage.
Serous retinal detachment signals this condition, which can be confirmed by
leakage of fluorescein into the subretinal space.Other late manifestations
of blunt injury to the RPE vary from minor atrophic changes to massive
hyperplasia and migration resulting in bone corpuscular and granular
pigmentation that resembles retinitis pigmentosa. If the trauma to the RPE
destroys photoreceptor cells, localized visual field defects result.
Destruction of the photoreceptors may be related to the release of catalytic
enzymes from lysosomes within the cytoplasm of the RPE.
In rare cases the retinal contusion causes cystoid macular edema that may, in
turn, progress to a macular hole .
Finally, it is possible that multiple pathogenetic mechanisms contribute to
the appearance of commotio retinae, depending upon the violence of the blunt
injury to the eye (i.e., in milder blunt trauma, there is only photoreceptor
damage and the gray-white opacification resolves, whereas in more severe trauma,
there is true macular edema and/or Müller cell damage, which may lead to
Berlin's edema is usually self limited and resolves without sequelae
, and there is no known intervention that alters its course and prognosis.