Abstract
Purpose :
Optic nerve head (ONH) avulsion is the traumatic separation of the optic nerve fibers at the lamina cribosa with intact the nerve sheath and adjacent sclera. It is a rare and usually visually devastating form of anterior traumatic optic neuropathy. We report cases of complete ONH avulsion following blunt ocular trauma.
Methods :
Medical charts, ocular imagings and radiological investigations were reviewed.
Results :
Two patients had sudden visual loss after motorcycle accident and slingshot rebounding attack. Their initial and final visual acuity (VA) was no light perception (LP). Microscopic hyphema, mild mydriasis and relative afferent pupillary defect were found in the first teenager. Fundus examination showed dense preretinal hemorrhage overlying the ONH area with surrounding retinal edema and vitreous hemorrhage. Although there were multiple displaced orbital fractures, normal eye globe and optic nerve contour were demonstrated on the computerized tomography. The intravenous methylprednisolone was prescribed. The second boy presented with partial corneal laceration and total hyphema. Ocular ultrasound showed normal globe contour, dense vitreous opacity and posterior lens dislocation. Due to questionable no light perception, pars plana vitrectomy was performed. Total ONH excavation and central retinal artery occlusion were found intraoperatively. The total retinal detachment and epimacular membrane developed one week later, however, the ONH was clearly seen and the optical coherence tomography revealed bottomless cup. A probable small gap of nerve at the entry point of globe was detected after reviewing the magnetic resonance imaging.
Conclusions :
Complete ONH avulsion is a rare manifestation of blunt ocular trauma. Radiological imaging usually could not detect the ONH avulsion which was support and obscured by the orbital tissue and optic nerve sheath. In case of media opacity, we suggest the visual evoked potential test for evaluation optic nerve function.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.