Ans. b. Berlin's edema Commotio retinae (Berlin's Edema) is of common occurrence following a blow on the eye. It manifests as milky white cloudiness involving a considerable area of posterior pole with a 'cherry-red spot' in the foveal region. It may appear after some days or may be followed by pigmentary changes."- Khurana 5/e p434 "Commotio retinae most frequently affect the temporal fundus. If the macula is involved, a `cherry-red spot' may be seen at the fovea."- Berlin's Edema (Commotio Retinae) Most commonly involves temporal fundus occasionally involves macula with a "cherry-red spot"Q Subsequen macular change will include progressive pigmentary degeneration and macular-hole formationQ Commotio retinae are a contrecoup injury to the retinaQ It can occur centrally or peripherally, and when it involves the macula, it is called Berlin's edemaQ The retina appears normal on examination although the patient may complain of decreased visionQ The affected area becomes white and opaque usually hours after the trauma.Q Berlin's "edema" is not a true edemaQ Swelling and disorganization of the outer retinal layers causes the opaqueness and there is no intercellular fluidQ Clinical Features: This occurs in blunt trauma to eye (e.g. Tennis ball injury to eye). The visual acuity in commotion retinae varies from 20/20 to 20/400 and does not always correlate with the degree of retinal opacification Course and Prognosis Berlin's edema is usually self-limited and resolves without sequelae There is no known intervention that alters its course and prognosis.