Título

ELECTROPHYSIOLOGICAL FINDINGS IN A TRAUMATIC OPTIC NEUROPATHY AFTER BLUNT OCULAR TRAUMA: A CASE REPORT

Objetivo

To report a case of traumatic optic neuropathy after blunt ocular trauma and its electrophysiological findings during the acute phase and follow up.

Relato do Caso

A 20-year-old man was evaluated with pain and loss of vision in the right eye after a blunt ocular trauma. Visual acuity was no light perception in the right eye and 0.00 logMAR (20/ 20) in the left eye. Slit lamp examination of the right eye revealed presence of vitreous and blood in the anterior chamber, dyscoria with superior iridectomy and subluxation of the lens. Fundus examination showed medium opacity, normal colored optic disc, attached retina and a diffuse retinal pallor in the right eye and normal aspect in the left eye . Full-field electroretinography (ERG) showed reduced amplitudes for both rods (96%) and cones (71%) in the affected eye compared with the fellow eye. Transient pattern-reversal visually evoked potentials (VEPs) were non-recordable and flash VEPs showed reduced amplitudes in the right eye. Both ERG and VEPs were within normal limits in the fellow eye. The initial management was conservative, with periodic clinical evaluation and investigation with ancillary tests. Head and orbit nuclear magnetic resonance demonstrated thickening and restriction of diffusion in the intraorbital segment of the right optic nerve. Ten weeks after the trauma the clinical exam of the right eye evidenced maintenance of no light perception and the fundoscopy showed a pallor optic disc with associated choroidal tear, suggesting the diagnosis of traumatic optic neuropathy . Seventeen weeks after the trauma, new electrophysiological exams evidenced maintenance of the initial findings.

Conclusão

The diagnosis of traumatic optic neuropathy was indicated by gathering the history of blunt ocular trauma, evidence of neuropathy due to a profound loss of vision, alterations in electrophysiological exams and late development of optic disc pallor.In this particular case, visual electrophysiological assessment in the acute phase has helped to better understand the evolution of this ocular neuropathy.