Case of Leber's hereditary Optic Neuropathy

This 50-year-old man presented with unexplained loss of vision in both eyes; there was a question of functional visual loss. He first noticed a gradual vision loss two years ago, stating the vision was getting hazy. The vision changes were noted in the right eye first followed by the left eye. Previous ocular history included mild cataracts and open angle glaucoma. Systemic illnesses include diabetes, hypertension, and Bell Õs palsy from an old head injury. The patient was noted to have a progressive visual field loss of unknown cause in a short time span. (See visual field images above) The patient had a MRI of the brain, optic nerves and chiasm, which was negative. The slit lamp exam was unremarkable with the exception of early cataracts in both eyes. The fundus exam showed pale optic nerves with the right worse.( See optic disc images, green arrows showing pale area. Blue arrows are pink healthy areas). An OCT image was performed which showed a loss of the retinal nerve fiber layer right eye worse than the left eye. (See OCT image above teal arrow). A MFERG was also performed and normal. Taken together these tests suggested a diagnosis of Leber's hereditary optic neuropathy. It was recommended that the patient have blood sent for mitochondrial DNA mutations that are associated with this condition, but cost considerations prevented the recommendation from being followed.