symptoms/signs/pathogenesis of cataract・Gradual loss of visual acuity
・Excessive glare, halos around bright lights
・Myopic shift
・Opacification of lens
・Loss of red reflex
・Photooxidative damage
Cumulative photooxidative stress is worsened by heavy UV exposure (eg, outdoor occupations), smoking, or ionizing radiation.
・Nuclear sclerosis
・Osmotic injury
accelerated in patients with diabetes mellitus ophthalmologyUWorld HirotoShishido
Pictureleft: "blood and thunder appearance"
→ retinal vein occlusion
right: macular star (exudate, red arrow), cotton-wool spots (blue arrow)
Retinal damage due to chronic uncontrolled HTN. Presence of papilledema requires immediate lowering of BP. ophthalmology HirotoShishido
Pictureoptic disk atrophy with characteristic cupping=thinning of outer rim of optic nerve head
→glaucoma
cherry red spot(☆bright red fovea centralis surrounded by a contrasting white macula→ central retinal artery occlusion, metachromatic leukodystrophy, Niemann-Pick, Tay-Sachs)
mechanism of sorbitol accumulationThe first step in the polyol pathway is the conversion of glucose into sorbitol by aldose reductase. Sorbitol cannot readily cross cell membranes and is therefore trapped inside the cells where it forms.
The second enzyme in the pathway, sorbitol dehydrogenase, is able to convert sorbitol into ☆fructose at a sufficient rate to prevent accumulation when glucose levels are normal.
adverse effect to ciliary muscle
of α-agonists, β-blockers, cholinomimeticsα-agonists (naphazoline)(↓aqueous humor synthesis (α2))→cannot used for closed angle glaucoma due to ☆mydriasis (α1)
β-blockers (timolol) decrease aqueous humor synthesis (β2) in ☆ciliary epithelium→ no pupillary or vision changes
closed angle glaucoma vs migrane with auraclosed angle glaucoma
→ typically older (> 60yo),
severe pain and conjunctival erythema are common, and vision would not be expected to improve without intervention
etiology of amblyopia• progressive suppression of visual input from eye receiving suboptimal image(blurry, deviated)
• in approximately half of the cases, amblyopia is secondary to strabismus (mainly ☆esotropia)
• other causes may include ★uncorrected refractive errors, anisometropia 不同視弱視 (asymmetric refractive errors, usually in the more ☆hyperopic eye), and deprivation due to structural ocular problems (ptosis, cataract, corneal opacity/scarring, retinoblastoma) ophthalmology卒試UWorld step2CK HirotoShishido