Otology & Ophthalmology, and specific drugs Flashcards
Each frequency leads to vibration at specific location on basilar membrane (tonotopy):
• Low frequency heard at _____
apex near helicotrema (wide and flexible).
Each frequency leads to vibration at specific location on basilar membrane (tonotopy):
•High frequency heard best at______
the base of cochlea (thin and rigid).
Noise-induced hearing loss and Presbycusis lose hearing in _____frequency
Loss of high-frequency
Cholesteatoma
Overgrowth of desquamated keratin debris within the middle ear space;
may erode ossicles, mastoid air cells - conductive hearing loss.
Often presents with painless otorrhea
Peripheral vertigo Tx:
Treatment:
C - anticholinergics H - antihistamines A - antiemetics S - low-salt diet E - Epley maneuver (BPPV). D - diuretics
Meniere disease triad:
sensorineural hearing loss
vertigo
tinnitus
Hyperopia corrects with:
Correct with convex (converging) lenses.
Myopia corrects with:
Correct with concave (d iverging) lens.
Cataract risk factors:
A - age
I - infection
D - diabetes mellitus
C - corticosteroid A - alcohol S - smoking T - trauma S - sunlight
3 - trisomies (13, 18, 21)
M - myotonic dystrophy
Torche - ToRCHeS infections
Milk - galactokinase deficiency /classic galactosemia
M - Marfan syndrome
A - Alport syndrome
N - neurofibromatosis 2
Open-angle glaucoma (Primary vs. secondary) causes:
Primary- cause unclear.
Secondary: blocked trabecular meshwork from
WBCs (eg, uveitis)
RBCs (eg, vitreous hemorrhage)
retinal elements (eg, retinal detachment).
Closed or narrow-angle glaucoma causes:
Primary- enlargement or anterior movement of the lens against central iris (pupil margin) - > obstruction of normal aqueous flow through the pupil.
Secondary- hypoxia from retinal disease (eg, diabetes mellitus, vein occlusion) induces vast proliferation in the iris that contracts angle.
Closed or narrow-angle glaucoma: Chronic vs. acute.
Chronic closure- often asymptomatic with damage to the optic nerve and peripheral vision.
Acute closure- true ophthalmic emergency. Very painful, red-eye, sudden vision loss, halos around lights, frontal headache, fixed and mid-dilated pupil, nausea, and vomiting.
Mydriatic agents contraindicated.
Uveitis - Posterior vs. anterior
Anterior uveitis: iritis;
posterior uveitis: choroiclitis and /or retinitis.
May have hypopyon
Age-related macular degeneration
Degeneration of macula (central area of the retina). It causes distortion (metamorphopsia) and eventual loss of central vision (scotomas).
Dry Age-related macular degeneration
% and cause
(nonexudative, > 80%)- Deposition of yellowish extracellular material (“Drusen”) in between Bruch membrane and retinal pigment epithelium with gradual dec. in vision. Prevent progression with a multivitamin and antioxidant supplements.
“Baruch (and pigment) the Druz”
Wet Age-related macular degeneration
% and cause
Wet (exudative, 10- 15%)-rapid loss of vision due to bleeding 2° to choroidal neovascularization. Treat with anti-VEGF (vascular endothelial growth factor) injections (eg, bevacizumab, ranibizumab).
Diabetic retinopathy - Nonproliferative
Damaged capillaries leak blood -> lipids and fluid seep into retina -> hemorrhages and macular edema.
Treatment: blood sugar control.
Diabetic retinopathy - Proliferative
Chronic hypoxia results in new blood vessel formation with resultant traction on the retina. Treatment: anti-VEGF injections, peripheral retinal photocoagulation, surgery
Hypertensive
retinopathy results in
Flame-shaped retinal hemorrhages
arteriovenous nicking
microaneurysms
macular star (exudate)
Retinal vein occlusion cause:
due to compression from nearby arterial atherosclerosis
“blood and thunder appearance”;
Retinal detachment pathology
Separation of the neurosensory layer of the retina (photoreceptor layer with rods and cones) from
outermost pigmented epithelium (normally shields excess light, supports retina)
Central retinal artery
occlusion
Acute, painless monocular vision loss.
The retina is cloudy with attenuated vessels and “cherry-red” spot at the fovea (center of the macula).
Evaluate for embolic source
Retinitis pigmentosa
progressive vision loss beginning with night blindness - rods in peripheral vision affected first
Papilledema
Optic disc swelling (usually bilateral) due to inc. ICP
