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These diverticula make their appearance before the closure of the anterior end of the neural tube; [1] [2] after the closure of the tube around the 4th week of development, they are known as the optic vesicles. Previous studies of optic vesicles suggest that the surrounding extraocular tissues – the surface ectoderm and extraocular mesenchyme ...
The optic vesicles then develop into the optic cup with the inner layer forming the retina and the outer portion forming the retinal pigment epithelium. The middle portion of the optic cup develops into the ciliary body and iris. [7] During the invagination of the optic cup, the ectoderm begins to thicken and form the lens placode, which ...
Example of a Mooney face, inverted (left) and right-side-up. The Mooney Face Test, developed by Craig M. Mooney, was first introduced in his 1957 article “Age in the development of closure ability in children.” [1] Participants in the test are shown series of black and white distorted photographs, presented in such a way that would require them to perform closure. [2]
The optic vesicles project toward the sides of the head, and the peripheral part of each expands to form a hollow bulb, while the proximal part remains narrow and constitutes the optic stalk. [1] [2] Closure of the choroidal fissure in the optic stalk occurs during the seventh week of development. The former optic stalk is then called the optic ...
In patients with headaches, the finding of swollen optic discs, or papilloedema, on fundus photography is a key sign, as this indicates raised intracranial pressure (ICP) which could be due to hydrocephalus, benign intracranial hypertension (aka pseudotumour cerebri) or brain tumor, amongst other conditions. Cupped optic discs are seen in glaucoma.
Rash, transitioning from papules to vesicles to pustules to scabs. Hutchinson's sign : cutaneous involvement of the tip of the nose, indicating nasociliary nerve involvement. While a positive Hutchinson's sign increases the likelihood of ocular complications associated with HZO, its absence does not rule out ophthalmic involvement.
PAX6 is essential is the formation of the retina, lens and cornea due to its role in early cell determination when forming precursors of these structures such as the optic vesicle and overlying surface ectoderm. [20]
Optic pits are associated with other abnormalities of the optic nerve including large optic nerve size, large inferior colobomas of the optic disc, and colobomas of the retina. The optic disc originates from the optic cup when the optic vesicle invaginates and forms an embryonic fissure (or groove). Optic pits may develop due to failure of the ...