Direct Ocular Injury (Nonpenetrating and/or Nonperforating)
Berlin’s Edema (Commotio Retinae)
Berlin’s edema or so-called commotio retinae is a zonal area of retinal whitening due to outer photoreceptor disruption and retinal pigment epithelial damage from blunt trauma that has led to edema of all retinal layers. There are no intraretinal cystic changes or bleeding in this form of trauma. It is believed that the mechanism is external force transmitted through the vitreous to the chorioretinal area, which induces outer retinal ischemia. These changes gradually resolve spontaneously but can cause late pigment atrophy.
Traumatic Retinal Pigment Epitheliopathy
Traumatic retinal pigment epitheliopathy may be predominantly atrophic, pigmentary, or fibrotic in nature. Eyes with minimal pigmentation, such as blue eyes, will tend to develop atrophy, while eyes with significant pigmentation in the pigment epithelium and choroid tend to develop hyperpigmentation. Depending on the extent of the trauma, any eye can develop fibrous degeneration.
Traumatic Macular Hole
Ocular trauma quite often results in a macular hole, particularly because the avascularity of the region may predispose a hole to form after a variety of insults. It is often accompanied by other chorioretinal injuries, including commotio retinae, choroidal rupture, and traumatic retinal pigment epitheliopathy. It may occur days to years post-injury. Trauma from a laser or lightning strike has also induced macular holes. While traumatic macular holes may close spontaneously, treatment generally involves the need for vitrectomy surgery with intraocular gas tamponade, and post-operative face-down positioning. The anatomic closure rate is quite comparable to idiopathic age-acquired macular holes, yet visual recovery may be limited due to the holes often being somewhat larger in size.
Choroidal Rupture
One or more choroidal ruptures may occur in association with blunt ocular trauma. A choroidal rupture is often associated with uveal and retinal pigment epithelial breaks and most commonly manifests as a white curvilinear streak concentric to the optic nerve temporally, but may have any morphological pattern or location and can even crisscross when multiple breaks occur. The choroid is quite susceptible to energy that gets imparted into the eye and/or orbit in association with an injury. Hemorrhage at the time of injury is common and secondary choroidal neovascularization may develop months to years post-injury, which can result in fibrotic scarring. Other manifestations of trauma are commonly seen in conjunction with a choroidal rupture.
Traumatic Retinal Breaks and Detachments
Trauma often leads to retinal breaks and detachment. Trauma generally involves younger, male patients in their second to third decade of life. In the setting of objective findings in association with ocular or periocular trauma (lid ecchymoses, etc.), the risk of retinal detachment is substantially increased. Detachments generally occur within two years of the traumatic event, and in most cases, within three months. Retinal dialysis is most common, and predominantly is located inferotemporally or superotemporally, but giant retinal tears and atypically shaped posterior horseshoe retinal tears are also seen. Very often these rhegmatogenous changes are seen in conjunction with other traumatic manifestations in the fundus. These injuries often lead to the need for scleral buckle and/or pars plana vitrectomy surgery to repair the damage.
Chorioretinitis Sclopetaria
Chorioretinitis sclopetaria is due to the simultaneous rupture of the retina and the choroid from a glancing nonpenetrating high velocity missile to the orbit, such as a bullet or a BB gun. Acutely, there is usually vitreous hemorrhage with extensive retinal and choroidal hemorrhage and widespread retinal necrosis. As the hemorrhage clears, claw-like breaks in Bruch membrane and the choriocapillaris become visible, with late-onset widespread pigmentary disturbances and varying degrees of glial proliferation. By definition, the globe is not ruptured.