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Eye color, specifically the color of the irises, is determined primarily by the concentration and distribution of melanin. Although the processes determining eye color are not fully understood, it is known that inherited eye color is determined by multiple genes. Environmental or acquired factors can alter these inherited traits. [7]
Vision loss in dominant optic atrophy is due to optic nerve fiber loss from mitochondria dysfunction. Dominant optic atrophy is associated with mutation of the OPA1 gene [9] found on chromosome 3, region q28-qter. Also, 5 other chromosomal genes are described as causing optic atrophy: OPA2 (x-linked), OPA3 (dominant), OPA4 (dominant), OPA5 ...
A slowly progressive optic neuropathy, dominant optic atrophy, usually presents in the first decade of life and is bilaterally symmetrical. Examination of these patients shows loss of visual acuity, temporal pallor of the optic discs, centrocecal scotomas with peripheral sparing, and subtle impairments in color vision.
However, papillitis may be unilateral, whereas papilledema is almost always bilateral. Papillitis can be differentiated from papilledema by an afferent pupillary defect (Marcus Gunn pupil), by its greater effect in decreasing visual acuity and color vision, and by the presence of a central scotoma. Papilledema that is not yet chronic will not ...
A necropsy study of 737 cases showed a 2.4% incidence with 2 out of 15 (13%) bilateral, [2] perhaps indicating the insidious nature of many cases. An autosomal dominant inheritance pattern with incomplete penetrance and associated inherited dysplasia of the optic disc and its blood supply is suspected.
Cone dystrophy; Fundus of a 45 year-old patient with cone rod dystrophy segregating with a loss-of-function mutation (E1087X) in ABCA4. Note the presence of various-shaped pigment deposits in the posterior pole with atrophy of the retina, while the retina appears less damaged in periphery (upper part of the photograph).
Leber's hereditary optic neuropathy (LHON) is a mitochondrially inherited (transmitted from mother to offspring) degeneration of retinal ganglion cells (RGCs) and their axons that leads to an acute or subacute loss of central vision; it predominantly affects young adult males.
Aniridia is the absence of the iris, a muscular structure that opens and closes the pupil to allow light into the eye.It is also responsible for eye color. Without it, the central eye appears all black.