Search results
Results from the WOW.Com Content Network
Progressive bifocal chorioretinal atrophy, also known for its abbreviations PBCRA or CRAPB, [1] is a rare, slowly progressive, autosomal dominant syndrome characterized by relatively large-sized atrophic hole-shaped lesions in the macular and nasal retina, myopia, low visual acuity, and nystagmus.
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.
The optic nerve can be damaged when exposed to direct or indirect injury. Direct optic nerve injuries are caused by trauma to the head or orbit that crosses normal tissue planes and disrupts the anatomy and function of the optic nerve; e.g., a bullet or forceps that physically injures the optic nerve.
The ophthalmic artery branches off into the central retinal artery which travels with the optic nerve until it enters the eye. [8] This central retinal artery provides nutrients to the retina of the eye, more specifically the inner retina and the surface of the optic nerve. [8] Variations, such as branch retinal artery occlusion, can also occur ...
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).
The exact mechanism of optic nerve ischemia in these cases remains unclear, but contributing factors may include hypotension, anemia, hypoxia, and changes in the autoregulation of optic nerve arterial blood flow. The incidence of ischemic optic neuropathy leading to vision loss following general surgeries ranges between 0.1% and 0.002%.
The optic disc may appear mildly hyperemic with small splinter hemorrhages on or around the disc, or may appear nearly normal. Optic atrophy typically develops later and may appear mild. In later stages the optic atrophy can become severe, which indicates less opportunity for recovery. [3]
In some cases—approximately 20% of the population—there is a branch of the ciliary circulation called the cilio-retinal artery which supplies the retina between the macula and the optic nerve, including the nerve fibers from the foveal photoreceptors. If this artery is present, the central vision will be preserved even in case of central ...