Purchase this article with an account.
Mithu Storoni, Gordon T. Plant, Wei Bi, John L. Barbur; Selective Sparing Of Rod / Melanopsin Driven Ganglion Cells In Leber’s Hereditary Optic Neuropathy (LHON). Invest. Ophthalmol. Vis. Sci. 2011;52(14):5313.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
In Leber hereditary optic neuropathy (LHON) it is generally assumed that loss of visual function such as acuity, colour and motion sensitivity is the result of significant damage to the principal classes of retinal ganglion cell (RGC). A histopathological study has shown LHON to affect parvo- more than magno-cellular neurones (1). More recent post-mortem evidence suggests the preferential sparing of intrinsically photosensitive RGCs (2) which may be involved in the control of the pupil light reflex (PLR). The purpose of this study was to examine whether PLR components are linked to different classes of ganglion cells and whether any of these components are spared in LHON patients.
Selective loss of visual function was quantified in LHON and compared to results obtained in age-matched normals. We measured high contrast acuity, contrast sensitivity, red/green and yellow/ blue colour thresholds and first order motion sensitivity. We also measured pupil responses to colour, motion and grating stimuli as well as light flux changes that stimulate preferentially rod photoreceptors and melanopsin.
The patients show almost complete absence of colour vision (both RG and YB), severe loss of motion and contrast sensitivity and poor high contrast acuity. These findings suggest significant loss of parvocellular cells and poor magnocellular function. Pupil colour and grating responses are also very small or absent. PLR responses (with large pupil responses to short wavelength stimuli that trigger large rod signal increments) were normal and similar to those elicited using achromatic stimuli that generate equivalent rod contrast signals.
The PLR response pathways that rely largely on rod/melanopsin signals can be spared in LHON.
This PDF is available to Subscribers Only