Flashcards in Ophthalmology - Pathology Deck (41):
What visual deficit does cataracts cause?
What is the pathogenesis of cataracts?
Painless, often bilateral opacification of lens.
What are the risk factors for cataracts?
Congenital: classic galactosemia, galactokinase deficiency
Acquired: Age. Smoking, etoh, excessive sunlight, prolonged corticosteroid use, DM (sorbitol), trauma, infection.
What visual defect does glaucoma cause?
Progressive peripheral vision loss
What is the pathogenesis of glaucoma?
Optic disc atrophy with cupping - thinning of outer rim of optic nerve head.
What are the two categories of glaucoma?
Open angle and closed/narrow angle
What are the risk factors and characteristics for open angle glaucoma?
Age, AA race, family history. More common in US. Painless.
Primary = cause unclear.
What are the causes of secondary open angle glaucoma?
Blocked trabecular meshwork from WBCs (uveitis), RBCs (vitreous hemorrhage), retinal elements (retinal detachment).
What is primary closed angle glaucoma?
Enlargement or forward movement of lens against central iris (pupil margin) --> obstruction of normal aqueous flow through pupil fluid builds up behind iris, pushing peripheral iris against cornea and impeding flow through trabecular meshwork.
What is secondary closed angle glaucoma?
Secondary—hypoxia from retinal disease (e.g., diabetes mellitus, vein occlusion) induces
vasoproliferation in iris that contracts angle.
What is the presentation of chronic closure glaucoma?
Often asx with damage to optic nerve and peripheral vision.
What is the presentation of acute closed angle glaucoma?
Emergency!! IOP pushes iris forward, angle closes abruptly. Very painful, red eye, sudden vision loss, halos around lights, rock-hard eye, frontal-headache.
What medication is contraindicated in acute closed/narrow angle glaucoma?
Epi. Causes pupillary dilation.
What is the uvea?
Iris, ciliary body, and choroid
What is anterior uveitis vs. posterior uveitis? Associated sx?
Anterior uveitis: Iritis
Posterior uveitis: Choroiditis
- may have hypopyon, conjunctival redness
What is hypopyon?
Accumulation of pus in anterior chamber (associated w/ uveitis).
What is uveitis associated with?
Systemic inflammatory disorders: Sarcoidosis, RA, JIA, HLA-B27 conditions
What is the visual defect in age-related macular degeneration?
Loss of central vision - scotomas.
What are the two types of age-related macular degeneration?
Dry (80%), and wet - exudative(10-15%).
What characterizes dry age-related macular degeneration?
Deposition of yellowish extracellular materal in and beneath Bruch membrane and retinal pigment epithelium: "drusen".
How can progression of age-related macular degeneration be prevented?
Multivitamin, antioxidant supplements.
What characterizes wet age-related macular degeneration?
Rapid loss of vision due to bleeding secondary to choroidal neovascularization.
How to treat wet age-related macular degeneration?
Anti-VEGF injections (eg ranibizumab) or laser.
What are the two types of diabetic retinopathy?
Nonproliferative and proliferative
What characterizes non-proliferative diabetic retinopathy?
Damaged capillaries leak blood. Lipids and fluid seep into retina. *Hemorrhages and Macular edema.*
What is the treatment for non-proliferative diabetic retinopathy?
Blood sugar control, macular laser.
What characterizes proliferative diabetic retinopathy?
Chronic hypoxia results in new blood vessel formation w/ resultant traction on retina.
What is the treatment for proliferative diabetic retinopathy?
Peripheral retinal photocoagulation, anti-VEGF (bevacizumab).
What does retinal vein occlusion look like?
Blockage of central or branch retinal vein due to compression from nearby arterial atherosclerosis causes retinal hemorrhage and venous engorgement + edema in affected areas.
What is the presentation of retinal detachment?
Vision loss. Often preceded by posterior vitreous detachment - flashes/floaters, and eventual monocular loss of vision (curtain drawn down).
What is the pathogenesis of retinal detachment?
Separation of neurosensory layer of retina (photoreceptor layer w/ rods and cones) from outermost pigmented epithelium (normally sheds excess light, supports retina). Causes degeneration of photoreceptors --> vision loss. Surgical emergency.
What may retinal detachment be secondary to?
Retinal breaks, diabetic traction, inflammatory effusions.
In patietns w/ what vision problems is retinal detachment more common?
Patients w/ high myopia.
What are the fundoscopic findings of retinal detachment?
Splaying and paucity of retinal vessels.
What does central retinal artery occlusion present as?
Acute, painless monocular loss of vision.
What are the fundoscopic findings of central retinal artery occlusion?
Retina cloudy with attentuated vessels and cherry-red spot at fovea (center of macula).
What is retinitis pigmentosa? What is the presentation?
Inherited retinal degeneration. Painless, progressive vision loss beginning with night blindness - rods affected first.
What are the fundoscopic findigns of retinitis pigmentosa?
Bone spicule-shaped deposits around macula.
What is the presentation of retinitis?
Retinal edema and necrosis leading to scar. (pizza hemorrhages).
What are common etiologies of retinitis?
Viral - CMV, HSV, HZV. Associated with immunosuppression.