Ocular Disorders Flashcards
(55 cards)
What are the different disorders?
Age-related Macular Degeneration (AMD)
Cataract
Diabetic retinopathy
Glaucoma
Under-corrected + uncorrected refractive error
What secondary conditions are people with vision impairment at greater risk to?
Falls
Depression
Increased risk of hip fracture
Increased early mortality
Social isolation
What does the retina contain?
Rods + cones
What are rods?
Sensitive to light
What are cones?
Sensitive to colours
What do cones need to be activated?
Light
Describe macula
Rich in cones
Degenerates = loses ability to see colours
What can happen if the retina detaches?
Leads to blindness if not fixed
What is AMD?
Chronic degenerative condition that affects central vision = not enough blood supply to area
Why does central vision disappear in AMD?
Deterioration of pigment layer of retina
What are the functional implications of AMD?
Difficulty distinguishing people’s faces
Difficulty with close work
Perceive straight lines as distorted/curved
Difficulty identifying edge of step
Unable to determine traffic light changes
Difficulty reading
What is cataract?
Clouding of the lens inside the eye
Why is blurred vision caused in cataract?
Light is scattered as enters eye = blurred vision
What can cause cataract?
Long term use of corticosteroids
Exposure to UV light
Ageing, smoking + diabetes
What are the functional implications of cataract?
Blurred vision
Reduced contrast
Difficulty judging depth
Halo/double vision around lights at night
Sensitive to glare + light
Dulled colour vision
What is diabetic retinopathy?
Small blood vessels of retina leak + bleed inside the eye
= “clouds” that obstruct sight
What are the functional implications of diabetic retinopathy?
Difficulty with fine details
Fluctuations in vision
Blurred, hazy or double vision
Difficulty seeing at night/low light
Sensitive to glare + light
Difficulty focusing
What is glaucoma?
Increased intraocular pressure due to malfunction in aqueous humour drainage system = optic nerve damage
What can relieving the pressure do in glaucoma?
Reduces progression of the disease
When is it considered closed angle glaucoma?
If trabecular meshwork is physically blocked by peripheral iris
When is it considered open angle glaucoma?
Still open but NO drainage system
What are the risk factors for glaucoma?
Extreme refractive error
Diabetes
Migraine
Cataracts
Previous eye injuries
Sleep apnoea
Male
Corticosteroids
What are the functional implications of glaucoma?
Difficulty adjusting to lighting changes
Occasional blurred vision
Halo around lights
Increased sensitivity to glare + light
Difficulty identifying edge of steps/road
Tripping over
What is refractive order?
Focusing disorder of the eye
