vision loss (gradual) Flashcards
causes of gradual vision loss
ABCDG // ARMD (dry) // blur // cataract // diabetes // glaucoma (open)
most common cause of blindness UK
age-related macular degeneration
RF ARMD
75+ // smoking // RF // IHD, hypertension, cholesterol, DM
dry ARMD symptoms + fundoscop
atropic // majority // drusen // gradual vision loss
wet ARMD + fundoscope
sudden vision loss // choroidal neovascularisation // red patches from retinal haemorrhage // drusen // worse prognoses
vision changes ARMD
CENTRAL reduced visual acuity // difficult in dark // flashing lights // distorsion of pictures // glare around images
what tests line distorsion
amsler grid (affected in ARMD)
invx ARMD
slit lamp // fluorcscein angio if wet ARMD // OCT to distinguish wet vs dry
mx ARMD
zinc + vit A, C, E // laser treatment
what usually causes blurred vision
refractive error!! // cataract // renital detachment // ARMD // glaucoma // optic neuritis // amaurosis fugax
invx blurred vision
snellen chart - visual accuity // fundoscope
what invx can test for refractive error
snellen + pinhole occlusion - corrects it
mx blurred vision
if gradual onset + refractive error –> optician // if pain or vision loss –> urgent opthalmology
what is a cataract
lens opacifies –> cloudy
causes cataracts
age // smoking, alcohol // DM // steroids // hypoCa!!
symptoms cataracts
gradual vision loss // faded colours // glare + halos around bright lights
inx cataract
no red reflex // normal fundus + optic nerve // slit lamp = cataract
types + causes of cataract (4)
nuclear - old age // polar - inherited // subcapsular = steroid // dot = normal or diabetes
mx cataract
surgery if visual impairment, decreased QOL, patient wants it
complications cataract surgery
retinal detachment // posterior capsule opacification or rupture // endophthalmitis
what is glaucoma
raised intraocular pressure
what is an open angle glaucoma
iris NOT occluding trabecular network so aquous humour CAN drain from eye
RF glauxoma
age // FH 1st degree // black // myopia (short sighted) // HTN, DM, steroids
symptoms open angle glaucoma
gradual vision loss // peripheral loss –> tunnel vision // decreased visual acuity
normal optic cup
colour, cup, disc // cup-to disc should be 0.4-0.7
fundoscope open glaucoma
optic cupping (>0.7) // pake disc // bayonetting of vessels
invx open glaucoma
perimetry (for visual field) // slit lamp (fundus) // goldmanns tonometry (IOP) >24// gonioscopy (ant chamber)
1st line mx open angle glaucoma (mechanism)
prostaglandin analogue eg latanoprost (increase uveascleral outflow)
SE latanoprost
brown iris, long eyelashes
mechanism timolol
BB blocker // reduces aquous solution
contraindication timolol
asthma or heart block
mechanism brimonidine
sympathetic (alpha 2 agonist) // reduces production + increases outflow
when should brimonidine be avoided
taking MAOi or TCA
mechanism pilocarpine
muscarnic agonist // increase uveoscleral outflow
mechanism Dorzolamide
Carbonic anhydrase inhibitor // reduce production
