Eye Anatomy and Physiology (Sos; 3-26-24) Flashcards
what is low myopia
-3 diopters or less
what is medium myopia
-3 to -6 diopters
what is high myopia?
-6 or more
Patient has high myopia, possible diagnoses?
glaucoma
retinal detachment
what are causes of diplopia?
Cataracts
Muscles: MG, Grave’s
Nerve: MS, DM, Gullian-Barre
Brain: stroke, tumor, aneurysm
fovea centralis is…
specialized region of macula lutea
200x increase in # of cone photoreceptors
foveola is…
no rods or BVs –> reduces light scatter –> highest visual acuity
what is the MC intraocular malignant neoplasm in adults?
uveal melanomas
incidence increases w/ age
where does retinal detachment happen? What can cause this?
between photo-receptors + retinal pigment epithelium.
- trauma
- hypertension
diabetic retinopathy causes
- microangiopathy = thick BM
- microhemorrhages
- edema
- hypoxia
what’s the most common cause of blindness in this country?
Age-Related Macular Degeneration (ARMD)
what happens in ARMD?
Neovascularization between the INNER CHOROID LAYER and BRUCH’S MEMBRANE (BM of retinal pigmented layer)
Tay-Sachs Disease causes what occular finding?
gangliosides accumulate in the ganglion cells in the retina
cherry red spot = only normal part of the retina
shows up in contrast to the retina
what is the MC primary intraocular malignant tumor in children? What is its cellular origin?
Retinoblastoma
cell of origin = neuronal
Flexner-Wintersteiner Rosettes
Retinoblastoma
small-blue tumor
RB gene
tumor suppressor gene
blocks gene transcription
blocks the cell cycle at G1
papilledema
bilateral
increased ICP
stasis of BF
stasis of axoplasmic transport in optic nerve head
glaucomatous optic nerve damage
increased IOP –> loss ganglion cells + thinning of retinal nerve fiber layer
advanced cases = optic disc cupped + optic nerve atrophy
