Male Prevalence of Acquired Color Vision Defects in Asymptomatic Carriers of Leber’s Hereditary Optic Neuropathy

Abstract

Male LHON asymptomatic carriers had color vision losses with the red-green pattern of dyschromatopsia typical of patients affected with LHON, which includes elevation of tritan thresholds as well. This predominantly parvocellular (red-green) impairment is compatible with the histopathology of LHON, which affects mostly the papillomacular bundle. In contrast with male losses, female losses were less frequent and severe. These gender differences are relevant to understanding LHON pathophysiology, suggesting that hormonal factors may be of great importance.

The Visual (dis)Function in Neurological Diseases

“…Both patient groups manifested significant losses along the protan and tritan axes, and the ON group had losses along the deutan axis as well. Such a tendency would suggest a greater impairment in the PC pathway, consistent with some results with other optic neuropathies such as Leber's hereditary optical neuropathy [135], but not others [136][137][138][139][140][141].…”

Visual acuity evaluation in children with hydrocephalus: An electrophysiological study with sweep visual evoked potential

“…Several studies in our laboratory show changes in visual functions in many neurological patients with normal ophthalmologic diagnosis [20][21][22].…”

Mouse mtDNA mutant model of Leber hereditary optic neuropathy

“…The percentage of optic atrophy in patients varies markedly among pedigrees. Male patients are two to five times more likely to develop blindness than female patients (2), and maternal relatives who have not progressed to subacute optic atrophy can still show signs of visual impairment (7,8).In LHON, optic atrophy is associated with preferential loss of the central small-caliber optic nerve fibers of the papillomacular bundle, resulting in central scotoma but with sparing of the largercaliber peripheral fibers and retention of peripheral vision. The loss of the optic nerve fibers is attributed to the death of retinal ganglion cells (RGC) as a result of the high energy demand placed on the unmyelinated portion of the optic nerve fibers anterior to the lamina cribosa, an area associated with high mitochondrial density (2).…”

“…The percentage of optic atrophy in patients varies markedly among pedigrees. Male patients are two to five times more likely to develop blindness than female patients (2), and maternal relatives who have not progressed to subacute optic atrophy can still show signs of visual impairment (7,8).…”