Visual System Review Flashcards
What is uveitis?
a group of inflammatory diseases often affecting the uvea. These diseases also affect the lens, retina, optic nerve, and vitreous, producing reduced vision or blindness
What are the main types of uveitis?
Anterior (Uveitis in the front of the eye. It is the most common form of uveitis, predominantly occurring in young and middle-aged people)
Intermediate
Posterior
Pan-uveitis
When does intermediate uveitis occur?
commonly seen in young adults. The center of the inflammation often appears in the vitreous (see diagram). It has been linked to several disorders including, sarcoidosis and multiple sclerosis.
Describe posterior uveitis
Posterior uveitis is the least common form of uveitis. It primarily occurs in the back of the eye, often involving both the retina and the choroid. It is often called choroditis or chorioretinitis. There are many infectious and non-infectious causes to posterior uveitis
What is pan-uveitis?
Pan-uveitis is a term used when all three major parts of the eye are affected by inflammation. Behcet’s disease is one of the most well-known forms of pan-uveitis and it greatly damages the retina.
What are the main categories of causes of uveitis?
- An attack from the body’s own immune system (autoimmunity).
- Infections or tumors occurring within the eye or in other parts of the body.
- Bruises to the eye.
- Toxins that may penetrate the eye.
C
C
What is Retinopathy of prematurity (ROP)?
- Retinopathy of prematurity (ROP) is a potentially blinding eye disorder that primarily affects premature infants weighing about 2¾ pounds or less that are born before 31 weeks of gestation
- About 400–600 infants each year in the US become legally blind from ROP.
T or F. Infants with ROP are considered to be at higher risk for developing future eye problems, such as retinal detachment, myopia, strabismus, amblyopia, and glaucoma.
T.
What is this?
Purtscher retinopathy - a hemorrhagic and vasoocclusive vasculopathy, associated with severe head trauma. These patients have findings of multiple white retinal patches (cotton-wool spots) and retinal hemorrhages that were associated with severe vision loss
Electroretinogram (ERG)
How does an Electroretinogram (ERG) work?
ØThe ERG records the electrical response evoked from the entire retina by a brief flash of light and consist of a “a” wave, a hyperpolarization effect of photoreceptor response, and a “b” wave that emanates from the Muller and bipolar cells.
ØOscillatory potentials (OP’s) are generated by amacrine cells
ØC-wave comes from RPE (not shown)
ERG is very useful to detect retinal diseases.
What is this ERG showing?
Central retinal artery occlusion (on the right; left=normal)
4
- Drusen
Describe the fundoscopic findings of mild HTN retinopathy
- Arteriolar narrowing and wall thickening with opacification
- Copper wire appearance of arteries – moderate vascular wall thickening
- Arteriovenous nicking (below)
What is this showing?
Cotton wool spots, indicative of retinal ischemia
What is this?
Drusen, yellow deposits under the retina. Drusen are made up of lipids, a fatty protein. While drusen likely do not cause age-related macular degeneration (AMD), their presence increases a person’s risk of developing AMD
What is this showing?
Grade IV HTN retinopathy- retinal exam show papilledema. There is blurring of the margins of the optic disc, distension of the retinal veins, two cotton wool spots inferior to the disc, and a flame-shaped hemorrhage at a venous bifurcation (arrow)
What is this?
This is a “copper wire” artery (pale section of normally red artery) and it indicates that the blood flow is restricted due to fatty deposits in the artery wall. The likely cause is hardening of the arteries
What is this?
This Gunn-Salus crossing is an example of a rigid artery wall. The artery wall is pressing on the vein causing it to deflect from its path in a zig zag pattern. This compression of the vein can cause a stroke.
What is this?
This more severe Gunn-Salus crossing is an example of a rigid artery wall. The artery wall is pressing on the vein causing it to deflect from its path in a zig zag pattern. This compression of the vein is so severe that the vein is almost closed off at the crossing
What is this?
This is High Blood Pressure. You will note that the artery is much smaller in caliber than the vein. It is almost 1/2 the size of the vein. In normal healthy vessels the ratio of size of the artery to vein should be 2:3 (not 1:2 as seen here).
- The patient turned out to have an AVM of the brain just above the right superior calcarine fissure (see next 2 slides). The lesion could have been a brain tumor, or the AVM could have bled to produce a hemorrhagic stroke. An ischemic stroke (infarct) is less likely to cause recurrent migraine-like visual aura which requires viable cortex for cortical spreading depression to occur.
