Cranial trauma often presents with varying ocular manifestations depending on the site of injury, the severity of the trauma, and the mechanism of injury.
Epidural Hematoma
Epidural hematoma is frequently associated with fractures of the parietal or temporal bones, often due to damage to the main trunk of the middle meningeal artery, commonly resulting in temporal hematomas. Without timely surgical intervention, this condition can be fatal. A key ocular sign of this condition is pupillary changes. Within minutes after the trauma, ipsilateral pupillary constriction and a sluggish light reflex may be observed, lasting for a few minutes. This is followed by progressive pupillary dilation and loss of the light reflex. One to two hours later, severe fixed dilation of the pupil can occur. Immediate medical intervention at this stage can often save the patient's life. Survival is rare if one or both pupils remain dilated and fixed for more than 30 minutes. Additional ocular findings may include oculomotor nerve palsy. In cases where epidural hematoma is accompanied by extensive cerebral contusion and laceration, preretinal hemorrhage may also be observed.
Subdural Hematoma
Subdural hematoma typically results from trauma-induced rupture of intracranial bridging veins. Ocular manifestations may include ipsilateral pupillary dilation. Mild head injuries generally do not produce changes in the fundus, while more severe cases may show mild optic disc edema, retinal edema, and venous engorgement. Oculomotor nerve palsy may also be present.
Skull Base Fracture
Skull base fractures frequently result in periorbital and subconjunctival hemorrhage in both eyes, presenting as the "raccoon eyes" sign. Anterior cranial fossa fractures may cause proptosis or subcutaneous orbital emphysema. Middle cranial fossa fractures can lead to pulsatile proptosis and signs of oculomotor nerve palsy.
Skull Fracture
Skull fractures are often accompanied by fractures of the optic canal. Fracture fragments can compress the optic nerve and lead to blindness. Patients may often be unconscious or in critical condition at the time of injury, making ocular signs easy to overlook. Without timely treatment, this can ultimately result in optic nerve atrophy. For individuals with cranial trauma, special attention should be given to changes in the pupils of both eyes. If a loss of the direct light reflex with preservation of the indirect light reflex on one side is identified, optic nerve damage on that side is indicated. Thin-slice orbital CT scans should be performed to detect optic canal fractures. If identified, optic canal decompression surgery can be urgently performed to preserve visual function.