Intro to opthamology Flashcards
What are the 2 refracting surfaces in the eye
The cornea and the lens
Where in the eye does light focus?
The macula
Where in the eye is the macula found?
The center of the retina
What is the medical term for short sightedness?
Myopia
What is the medical term for long sightedness?
Hypermetropia
What happens to the length of the eyeball in myopia?
The eyeball is long
What happens to the length of the eyeball in hypermetropia?
The eyeball is short
Where does the image focus in myopia?
In front of the retina
Where does the image focus in hypermetropia?
Behind the retina
What leads to double vision?
Misalignment of the visual axis
What happens if there is inflammation in the orbit?
The eyes bulge out
What does the orbit of the eye contain?
The eyeball, muscles, vasculature, nerves, lacrimal gland, drainage system
What is the medical term for bulging of the eye?
Proptosis/ exophthalmos
What does fracture of the orbit cause?
Enopthalmos
Why may there be restricted eye movements in a fracture of the orbit?
A muscle may get trapped
What is colobomas?
Disruption of the fusion process which forms the eyeball
When during embryo development does the optic vesicle develop?
Week 4
What years of a child’s life are most crucial for visual development?
The first 7 years
After what age can a lazy eye not be remedied?
After 7 years of age
What is the legal definition of blindness?
So blind that they cannot do any work for which eyesight is essential
What is the most common cause of blindness?
Cataracts (age related) and wrong glasses
What is trachoma?
When due to inflammation the eyelid and eyelashes are pushed backwards, this causes eyelashes to abrade the eye leading to conjunctival scarring
In the UK which demographics are more likely to be blind?
Women and those from minority ethnic backgrounds
How does age related macular degeneration cause poor vision?
There are changes to the retina which causes scarring and affects vision
What are the 2 types of age related macular degeneration ?
Dry and wet
What is the difference between the 2 types of age related macular degeneration?
Wet is accelerated visual loss
How may wet age related macular degeneration present?
Sudden visual loss, distortion, blood at macula
How is age related macular degeneration treated?
Anti-VEGF injections
How is age related macular degeneration prevented?
Avoiding smoking, having good nutrition and cardiovascular health
What type of complication is diabetic retinopathy?
Microvascular
How is diabetic retinopathy treated?
Intravitreal injections
What is glaucoma?
Progressive optic neuropathy characterised by optic disc changes and following visual field defects
What happens to intra ocular pressure (IOP) in glaucoma?
It might be raised but it is possible it will stay normal
What structure does glaucoma affect and how does it progress?
It affects the optic nerve by progressively eroding it from the center outwards, it is irreversible
How is glaucoma treated?
Eyedrops to lower IOP
What is cataract?
Clouding of the lens
How is cataract treated?
Extraction in surgery and replacement with intra ocular lens implant
What is the pathophysiology of thyroid eye disease?
Cross reactivity of antibodies targeting antigens in the thyroid and the orbit (IGF1-R and TSHR)
What are the 2 main life and death situations in opthamology?
Aneurysm (causing non pupil sparing 3rd nerve palsy) and temporal arteritis
How will aneurysm causing non pupil sparing 3rd nerve palsy present?
Headache, droopy eyelid, when eyelid is lifted eye is down and out, pupils are fixed and dilated
How does aneurysm causing non pupil sparing 3rd nerve palsy arise?
The oculomotor nerves runs along the posterior communicating artery, the aneurysm compresses the nerve
How will temporal arteritis present?
Acute loss of left vision, loss of appetite, headaches, sore scalp, pain on chewing food
What are the conditions for diagnosis of temporal arteritis?
Age of onset is over 50 years
Headache must be new, ESR over 50 mm/h
Abnormalities in temporal arteries and positive biopsy of artery
