In Reply.
—Clinical observations indicate that the retinal opacity in traumatically induced commotio retinae is at the level of the outer, sensory part of the retina. In traumatized primate eyes, direct correlation of the area of opacified retina and its histologic appearance confirms that immediately after trauma the only abnormality is disruption of receptor cell outer segments. No cytoplasmic edema of the inner part of the retina (ganglion cell axons) or glia cells is present. We cannot tell whether the findings of Hart and Blight result from examination of directly traumatized retina (rather than the contrecoup areas of posterior pole retina we examined) or from a different response of the pig eye compared to the primate eye. The findings in the primate, however, closely simulate the clinical and fluorescein angiographic features of human commotio retinae.The visual acuity after commotio retinae involving the macular area would seemingly depend on the