<unk>  is a rare subtype of primary central nervous system<unk> .<unk>  may affect the eye secondarily from metastasis from a non-ocular tumor or may arise within the eye primarily. According to the World Health Organization (WHO) classification,<unk> s are most commonly a diffuse large B-cell immunohistologic subtype of non-Hodgkin's<unk> . The most common symptoms of<unk>  are blurred or decreased vision. In the majority of patients, central nervous system involvement only accounts for 20% of primary central nervous system<unk> s. The median age at diagnosis among patients with<unk>  is between 50-60 years.  The pathogenesis of<unk>  is characterized by the affection of the sub-retinal pigment epithelium, which is normally involved in the light absorption.  On fluorescein angiography, findings may reveal "leopard spot" patterns due to sub-retinal pigment epithelium infiltrates that stain early and progressively or mottling of the sub-retinal pigment epithelium due to hyper- and hypo-fluorescent window defects.  The initial therapy for patients with<unk>  is corticosteroids.
Intraocular lymphoma
Graves ophthalmopathy
Optic nerve glioma
Anterior ischemic optic neuropathy
Lacrimal gland tumor
Open-angle glaucoma
Endogenous endophthalmitis
Bacterial endophthalmitis