Diktyoma mitotic activity, sarcomatous components, or invasion into the uvea, cornea, or sclera. Most diktyomas are malignant. The most common symptoms of diktyoma are vision loss and pain, while the most common signs are leukocoria and presence of a mass in the iris or ciliary body. Other signs and symptoms include lens subluxation, glaucoma, cataract, exophthalmos, buphthalmos, strabismus, and ptosis. Imaging studies such as ultrasonography (US), Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI) may aid diagnosis. On ultrasound, diktyomas typically appear as echogenic, irregularly shaped to ovoid masses. Ultrasound is excellent for demonstrating cystic collections of vitreous fluid in the
Iris sphincter muscle reflex) or during accommodation. In lower animals, the muscle cells themselves are photosensitive causing iris action without brain input. It is controlled by parasympathetic fibers of the muscarinic acetylcholine receptor (M3) that originate from the Edinger-Westphal nucleus, travel along the oculomotor nerve (CN III), synapse in the ciliary ganglion, and then enter the eye via the short ciliary nerves.. The short ciliary nerves then run forward and pierce the sclera at the back of the eye, traveling between the sclera and the choroid to innervate the iris sphincter muscle. Iris sphincter muscle The iris sphincter muscle (pupillary sphincter, pupillary constrictor,