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Optic nerve sheath meningiomas (ONSM) are rare benign tumors of the optic nerve. 60–70% of cases occur in middle age females, and is more common in older adults (mean age 44.7 years). It is also seen in children, but this is rare. The tumors grow from cells that surround the optic nerve, and as the tumor grows, it compresses the optic nerve.
Optic nerve melanocytoma does not usually produce symptoms or grow. If they slowly grow, optic nerve melanocytoma can produce afferent pupillary defects (30%), subretinal fluid (10%), and an enlarged blind spot (75%). On fundoscopic exam, the optic disc may be swollen, atrophic, or even normal. [1] Central retinal vein occlusion may occur.
There are three stages a patient with the disease goes through: First stage: This is the initial phase of the condition, and it takes place from birth to the age of 14 years old; [6] it is characterized by the appearance of a large, perforated chorioretinal atrophic lesion at the central part of the macula which contains the vascular arch, alongside extra-macular white deposits and localized ...
Presumed ocular histoplasmosis syndrome (POHS) is a syndrome affecting the eye, which is characterized by peripheral atrophic chorioretinal scars, atrophy or scarring adjacent to the optic disc and maculopathy. The loss of vision in POHS is caused by choroidal neovascularization.
A nerve sheath tumor is a type of tumor of the nervous system (nervous system neoplasm) which is made up primarily of the myelin surrounding nerves. Nerve sheath tumors can be benign or malignant , and may affect both the peripheral and central nervous systems .
The retinal circulation, on the other hand, derives its circulation from the central retinal artery, also a branch of the ophthalmic artery, but passing in conjunction with the optic nerve. [3] They branch in a segmental distribution to end arterioles and not anastomoses. This is clinically significant for diseases affecting choroidal blood supply.
Lesions involving the whole optic nerve cause complete blindness on the affected side, that means damage at the right optic nerve causes complete loss of vision in the right eye. [3] Optic neuritis involving external fibers of the optic nerve causes tunnel vision. [4] Optic neuritis involving internal fibers of the optic nerve causes central ...
Recently, central serous chorioretinopathy has been understood to be part of the pachychoroid spectrum. [5] [6] In pachychoroid spectrum disorders, of which CSR represents stage II, the choroid, the highly vascularized layer below the retina, is thickened and congested with increased blood vessel diameter, especially in the deep choroid (the so-called Haller's layer).