To the Editor.
—With reference to the recent article by Sipperley et al (Archives 96:2267-2273, 1978), we feel that a distinction should have been made between commotio retinae resulting from nonperforating mechanical injuries to the globe in which visual impairment is transient and retinal opacification clears without sequelae within a matter of days, the more common form, and the condition in which, following resolution of traumatic clouding, cystic maculopathies or retinal epithelial disturbances become apparent; visual function in these cases is often severely and permanently impaired.The authors, in their study of the pathologic changes responsible for traumatic retinal opacification in primates, have provided valuable information about the processes involved in the production of posttraumatic pigmentary retinopathies. Investigations carried out for patients with traumatic retinal edema in whom pigment changes later developed confirm that when fluorescein angiographic studies are performed soon after injury, staining of the pigment epithelium may develop.