Kjer's optic neuropathy

Abstract

Kjer's optic neuropathy, also known as optic atrophy type 1 (OPA-1), is a genetic condition that usually presents with the bilateral pallor of the optic disc (OD) associated with decreased visual acuity (VA), in addition to defects in the visual field (VF) and color vision. This article aims to report a case of OPA-1 diagnosed through genetic testing. A 22-year-old male patient searched for neuro-ophthalmological care, complaining of low VA, difficulty adapting to both light and dark, and photophobia in both eyes (BE) since 6 years old. He denies VF loss, nyctalopia, or hearing deficit and has maternal relatives with similar conditions. The patient presented VA of 20/63 in the right eye (RE) and 20/50 in the left eye (LE) with dyschromatopsia and bilateral OD pallor, in addition to reduced foveal brightness. Humphrey's visual perimetry showed centrocecal scotoma in the LE only and a nonspecific loss in the RE. He brought a pattern electroretinography (PERG) examination showing the reduced function of ganglion cells in the macular area and optic nerve in BE and multifocal electroretinogram with cone system function slightly reduced in BE. A genetic panel was performed to search for mutations in the OPA-1 gene, which showed a variant associated with this disease in the patient described and in his mother. Thus, this report exemplifies a case of OPA-1 hereditary OPA, emphasizing the importance of combining clinical evaluation, electrophysiological, and genetic tests for a precise and accurate diagnosis.

Keywords

• genetic counseling
• optic atrophy
• visual acuity