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Flashcards in Pathology - ophtho Deck (18):
1

Aqueous humor pathway

ciliary epithelium --> posterior chamber --> sphincter --> anterior chamber --> trabecular meshwork --> Canal of Schlemm

2

Glaucoma drugs

decr. aq humor synth: epinephrine, brimonidine, timolol, acetazolomide

incr. aq humor outflow: pilocarpine (opening of trabecular meshwork), physostigmine (both are cholinomimetics)

3

Eye too short for refractive power of cornea and lens

Hyperopia (light focused behind retina)

4

Eye too long for refractive power of cornea and lens

Myopia (light focused in front of retina)

5

Impaired accommodation due to loss of elasticity

Presbyopia

6

Painless bilateral opacification of the eye

Cataract

Can be caused by steroids, sunlight, galactose excess, DM, infection

7

Optic disc atrophy with cupping

Glaucoma

usually seen with incr. IOP

8

Open vs. closed angle glaucoma

Open angle - blocked trabecular meshwork

Closed angle - obstruction of aq humor flow by lens pushing on the iris (which blocks flow through trabecular meshwork)

9

Vision changes in macular degeneration

distortion and loss of central vision (scotoma!)

dry = deposition of yellowish material in and beneath Bruch membrane and RPE --> drusen

wet = rapid loss of vision due to bleeding secondary to choroidal neovascularization, treat with anti-VEGF or laser

10

Non-proliferative vs. proliferative diabetic retinopathy

NP: damaged capillaries leak blood, causing hemorrhages and macular edema

P: chronic hypoxia causes neovascularization --> traction on retina

11

Layers in retinal detachment

Separation of neurosensory layer from the pigmented epithelium

12

Progression of retinitis pigmentosa

Starts with night blindness (loss of rods first!)

Look for bone spicule-shaped deposits around macula

13

Miosis vs. Mydriasis

Constriction (parasympathetic, 2 neurons, short ciliary nerve) vs. dilation (sympathetic, 3 neurons, long ciliary nerve)

14

Ptosis + down and out gaze + blown pupil

3rd nerve palsy

Motor output affected by vascular disease (is on inside of CN3, whereas vasculature runs on the periphery)

Parasympathetic output affected first by compression (PCOMM aneurysm, uncal herniation)

15

Head tilt + eye moving upward with contralateral gaze

4th nerve palsy

Look for problems going down stairs

16

Medially directed eye that can't abduct

6th nerve palsy

17

Meyer loop vs. dorsal optic radiation

Meyer loop = inferior retina, loops around inferior horn of lateral ventricle

Dorsal optic radiation = superior retina, takes shortest path via internal capsule

18

Impaired adduction

Sign of internuclear ophthalmoplegia

MLF lesion = lack of visual coordination in horizontal field (lack of contralateral CN3 firing), nystagmus opposite to lesion

Left INO = left eye is paralyzed