Neuro17 Flashcards
Eye conditions Glaucoma Cataract Papilledema
What are the 5 refractive errors causing impaired vision that improves with glasses?
Hyperopia Myopia Astigmatism Accommodation Presbyopia
Describe Hyperopia.
Eye too SHORT for refractive power of cornea and lens
*Light-focused BEHIND retina
Describe Myopia.
Eye to LONG for refractive power of cornea and lens
*Light focused in FRONT of retina
Describe Astigmatism.
Abnormal curvature of cornea
*Different refractive power at different axes
Describe Accommodation.
Focusing on near object
*occurs with convergence and miosis
Describe the what happens to the eye during accommodation.
1-Ciliary muscles tighten
2-Zonular fibers relax
3-Lens becomes more CONVEX
4-Focus on near objects
Describe Presbyopia.
DEcreased change in focusing ability during accommodation
*d/t Sclerosis & decreased elasticity
What is Uveitis?
Inflammation of the uveal coat
-Consists of: Iris, Ciliary body, & Choroid
Uveitis is associated with.
Systemic Inflammatory disorders
-Sarcoid, RA, JIA, TB, HLA-B27 conditions
What is Retinitis?
Retinal edema and necrosis leading to scar
What causes Retinitis?
Viral (most common)
-CMV, HSV, HZV
*Associated w/ immunosuppression
What is Central Retinal Artery Occlusion?
Acute, painless monocular vision loss
*Retina whitening w/ cherry-red spot
What collects aqueous humor from the trabecular meshwork?
Canal of Schlemm
What collects aqueous humor that flows through the anterior chamber?
Trabecular meshwork
What produces aqueous humor?
Ciliary epithelium (ß)
What optic neuropathy is usually associated with INcreased intraocular pressure (IOP)?
Glaucoma
Open/wide angle Glaucoma is characterized by:
- Peripheral then Central vision loss
- Optic disc atrophy w/ Cupping
- Increased IOP
Is open/wide angle glaucoma painful?
NO
What causes open/wide angle glaucoma?
- Primary cause unclear
- Secondary causes
- uveitis, trauma, corticosteroids & vasoproliferative retinopathy that can block or DEcrease outflow at the trabecular meshwork
What is Closed/Narrow angle glaucoma?
1-Enlargement or Forward movement of lens against central iris
2-Leads to Obstruction of normal aqueous flow through pupil
3-Fluid builds up behind iris, pushing peripheral iris against cornea and impending flow through the trabecular meshwork
What are the two types of Closed/Narrow angle glaucoma?
Chronic closure
Acute closure
What is chronic closure (Closed/Narrow angle glaucoma)?
Asymptomatic w/ damage to optic n. and peripheral vision
What is acute closure (Closed/Narrow angle glaucoma)?
- True opthalmic emergency
- INcreased IOP pushes iris forward -> Angle closes abruptly
*Very painful, Sudden vision loss, rock-hard eye, frontal headache
What should you avoid giving in acute closure (Closed/Narrow angle glaucoma)?
Epinephrine because of its mydriatic effect
What is a cataract?
Painless opacification of lens leading to DEcreased vision
T/F Cataracts are often bilateral.
True
What are risk factors for developing cataracts?
Age Smoking EtOH Sunlight Corticosteroid overuse Galactosemia (classic) Galactokinase deficiency Diabetes (sorbitol) Trauma Infection
What is papilledema?
Optic disc swelling due to INcreased intracranial pressure
T/F Papilledema is often bilateral.
True
What are the clinical signs and symptoms of papilledema?
Enlarged blind spot
Elevated optic disc w/ blurred margins (seen on fundoscopic exam)
