Leber's Hereditary Optic neuropathy is a mitochondrially inherited condition due to one of three types of mitochondrial mutation. It causes acute or sub acute degeneration of retinal ganglion cells and their axons resulting in loss of central vision. Ref: A.K KHURANA (2005), Chapter 12, "Vision and Neuro-Opthalmology", In the book, "Opthalmology", 3rd Edition, Newdelhi, Page 281