Completion of Eye pathology Flashcards
Draw the pathway for aqueous humor. include waht produces it, and receptors on the muscles
see pg 478
What is glaucoma?
optic disc atrophy with characteristic cupping, usually with increased intraocular pressure and porgressive visual field loss
What is open angle glaucoma? types? painful/painless
glaucoma that isn’t caused by blocked aqueous flow through the pupil. painless
May be primary (cause unknown) or secondary (d/t blocked trabecular meshwork that collects humor from the anterior chamber to the canal of schlemm. may be bloced by WBCs, RBCs, or retinal elements)
risk factors for open angle glaucoma
age, Af am race, family hx
primary closed angle glaucoma
enlargement or forward movement of the lens against the central iris leading to obstruction of normal aqueous flow through the pupil. the fluid builds up behind the iris,which pushes the iris against the cornea and impedes flow through the trabecular meshwork.
what is secondary closed angle glaucoma
hypoxia from retinal disease (like DM, vein occlusion) induces vasoproliferation in the iris that contracts the angle
What are clinical characteristics of chronic closure glaucoma? painful/painless
asymptomatic with damage to the optic nerve and peripheral vision. no pain.
acute narrow angle glaucoma: pathophysiology, painful/painless
true ophthalmic emergency. incr. intraocular pressure pushes the iris forward and the angle closes abruptly. it will be PAINFUL with sudden vision loss, halos around lights hard eyes, and frontal headache NO epinephrine
What drugs are contraindicated in acute narrow angle glaucoma? Why?
no epinephrine- mydriatic effects will further close the angle.
What is a cataract? painful/painless
painless, often bilateral opacification of the lens causing a decr. in vision.
risk factors for cataracts
age, smoking, EtOH, excessive sun, prolonged corticosteroids, classic galactosemia, galactokinase deficiency, DM, trauma, infection
What are some findings on exam that would indicate papilledema?
enlarged blind spot and elevated optic disc
How does mydriasis occur? decribe the neurons involved
dilation: sympathetic function
1st neuron: hypothalamus to ciliospinal center of budge (C8-T2) (remember, sympathetics are thoracic)
2nd neuron: exit at T1 to sup. cervical ganglion
3rd neruon: plexus along the internal carotid, through cavernous sinus; enters the orbit as the long ciliary nerve to the pupillary dilator muscles
