Unroofing of the Optic Canal Through Transfrontal Intradural Approach in Cases of Traumatic Optic Nerve In jury

Abstract

Eleven cases of traumatic optic nerve injury had been treated operatively in our clinic. All cases were male and the patients were struck on the areas above or lateral to the orbit by a fall from a bicycle or a motor cycle in most cases.
The unroofing of the optic canal was performed after various intervals from the trauma and in only three cases it was more or less effective. One of these three cases was briefly summarized; Case 10, an 8 y. o. boy, had restored visual acuity to 0.02 by the operative treatment on the third day from the trauma. No fracture nor deformity of the optic canal was noted on the X-ray films. Fracture of the medial wall, however, was noted at the time of operation and no apparent contusion of the optic nerve was found, but the optic nerve was seen to be bulged after unroofing.
Two critical factors, the interval between operation and trauma and the degree of injury, seem to determine the functional prognosis after the operative treatment. Decompression of the optic nerve should be undertaken as soon as possible after the trauma and, as the value of X-ray examination to visualize the optic canal fracture is limited, the operative decompression of the optic canal may be indicated promptly from the clinical state of the patient.
The unroofing of the optic canal was performed through the transfrontal intradural approach because of easiness of orientation and complete unroofing for full length of the optic canal, and of less blood loss than through the extradural route.