Opthamology Flashcards
when the optic duct doesn’t form correctly what does it form?
and what does this look like?
coloboma
pupil has irregular shape
what is blindness legally defined as?
‘so blind that they cannot do any work for which eyesight is essential’
(there is no legal definition for visual impairment or partial sight)
What is the global leading cause of blindness?
Cataracts (40%)
How many people go blind because of refractive errors and how can these be treated?
150 million
glasses
How much of blindness is preventable?
80%
How does trauchoma cause blindness?
It causes conjunctivitis (conjunctiva are what covers the inside membrane the of the eyelids),
so when the conjunctiva contract he eyelashes are rotated in and scar or ulcerate the front of the eye leading to visual impairment.
(it is a highly infectious/spread disease - combatted with improving the environment, hygeine, sanitation & education by vision 2020)
How many times more likely are adults with learning disabilities to get eyesight loss?
ten times
What is one group with greater risk for sight loss?
Black or other ethnic minority groups
Diseases of what part of the eye is the leading cause of blindness in the UK?
the macula
What do people with poor eyesight in the UK have a higher chance of?
depression (2.6x)
falls (1.4x)
What is the leading cause of visual loss in the UK?
Age-related macular degeneration
Age-related macular degeneration
No treatment of dry type. Wet type is still a dramatic presentation.
How to treat Wet Age-related macular degeneration?
Intravitreal anti-VEGF (several injections)
causes great regression of abnormal lesion
What is the leading cause of poor vision in the UK?
Diabetic Retinopathy
a microvascular complication of diabetes
How does the Diabetic Retinopathy Screening Program work?
everyone above the age of 12 should have a yearly check for diabetic retinopathy
How to treat diabetic retinopathy?
first line treatment - laser photocoagulation (doesn’t cure, just slows degradation) (laser is also destructive) (may stabilise but cannot restore vision)
How to treat diabetic maculopathy?
Intravitreal Injections (although this can be very expensive, eg. some clinics 300-400 injections per week & £800 per injection)
What is the second leading cause of blindness in the UK?
Glaucoma (A progressive optic neuropathy characterized by typical optic disc changes and commensurate visual field deficits)
What percentage of UK glaucoma patients are diagnosed?
50%
Why can glaucoma be hard to diagnose?
many glaucoma patients have normal eye pressure, despite having optic disc damage.
most have abnormal pressure with their optic disc damage.
Who is glaucoma more prevalent in?
Black or other ethnic minorities
What is the mechanism of glaucoma?
Not enough drainage to the eye, so damages the optic disc causing a greater hole in the centre (like a donut)
How to test for glaucoma?
Visual Fields test
How does a glaucoma patient’s vision differ?
Their peripheral vision is hazed out/more blurry/less clear
How to treat glaucoma?
Drops that reduce the intraocular pressure
What is the leading cause of blindness in the world?
Cataracts
How does a cataracts patient’s vision differ?
Their vision is more blurry
How to treat cataracts?
an ultrasound probe breaks up the harder thicker parts of the cataract, and use another suction instrument to hoover up the remnants of the lens - and you are left with a clear bag at the end - ready to receive your impant.
the wound left is self-healing, this is especially useful as this minimises distortion to the eye.
you inject the lens with the introducer which unfolds and is pushed into palce.
usually done under local anaesthetic, or even just eyedrops
(used to incise the eye and put in implant)
(also wear very thick glasses)
What is cataracts?
medical condition in which the lens of the eye becomes progressively opaque
A 56 year old female presents headache droopy left eyelid when you lift the eyelid her eye is ‘down and out’ observe her pupils- why does it matter?
Oculomotor Nerve - CNIII lesion
painful CNIII palsy is a neurological emergency
a 76 year old lady comes in acute loss of left vision Loss of appetite headaches sore scalp pain on chewing food
temporal arteritis Age at onset>50 years New headache Abnormalities of the temporal arteries ESR >50 mm/h Positive temporal artery biopsy can cause blindness quite rapidly
