Flashcards in Ophthalmology Deck (44):
What are the eye drops to dilate the pupil?
Tripicamide (may blurr vision for an hour)
What are the three key areas to look at in ophthalmoscopy?
Retina, optic nerve, macula
What is seen in glaucoma?
Change in colour of optic nerve
Optic nerve cupping
What is seen in diabetic retinopathy?
New blood vessel growth
What is seen in AMRD?
Trusen/yellow spots on retina
What is the overall structure of the visual pathway?
Eye, optic nerve, optic chiasm, lateral geniculate body, optic tract, occipital lobe
Where does the lateral portion of the eye see and does information cross at the chiasm?
Where does medial portion of the eye see and does information cross the chiasm?
What does a lesion in L optic nerve cause?
What does a lesion in the optic chiasm cause?
What does a lesion in L optic tract occur?
Right homonymous hemianopia
What does damage to macula cause (central scomata/macular degeneration)?
Loss of central vision
First stage of ophthalmoscopy?
Red reflex (light reflecting back from retina)
Procedure of ophthalmoscopy?
Follow retinal vessel to reach the optic disc
Assess the optic disc: Cup, Colour, Contour
Follow the 4 vascular bundles (each has artery and vein)
Ask patient to look up, down, to left and right (follow eye and look for peripheral changes)
Ask patient to look directly at light to visualise the macula
What are the 3 overall layers of the eye?
Fibrous, vascular and inner layer
What makes up the fibrous layer?
Sclera (white part) and cornea (transparent and central, refracts light)
What makes up the vascular layer?
Choroid (nourishes retina), ciliary body (encircles eye, made of ciliary muscle and ciliary processes), iris (colour part with hole in middle for pupil)
What happens when the ciliary smooth muscles contract?
Accomodation for near vision: Less tension in the zonula fibres
What is the ciliary body attached to?
The lens via zonular fibres (make up the suspensory ligament)
What happens when the ciliary muscle relaxes?
For distance vision
More tension in the zonula fibres pulling the lens flatter
Main function of the ciliary body?
Production of aqueous humour
What are the two types of fibres in the iris and innervation?
Circular: Parasympathetic (contraction)
Radial: Sympathetic (dilation)
What is the anterior chamber?
Between the cornea and iris
What makes up the inner layer of the eye?
The retina (neural layer and pigment layer)
What does the fovea of the macula contain?
High concentration of cones (light sensitive receptors)
What is the optic disc?
Area where the optic nerve enters the retina (no light detecting cells - blindspot)
Central retinal artery also enters here
Where is posterior chamber?
Between iris and lens/suspensory ligaments
What is the flow of aqueous humour?
Secreted into posterior chamber flowing via pupil into anterior chamber and absorbed by canal of schlemm/scleral venous sinus (encircles the eye at the iris corneal junction)
What happens in glaucoma?
Raised intraocular pressure due to dysfunction of the aqueous drainage system
Where is the vitreous chamber?
Behind the lens to retina
What do rods detect?
black and white
What do cones detect?
What is the innervation of the extraocular muslces?
What muscles move the abducted eye up and down?
What muscles move the adducted eye up and down?
(doesn't innervate LR or SO)
Eye down and out, eyelid down (levator ani)
Cant depress the adducted eye
Eye sits up a little and head tilted away affected side
Adducted eye/cross eye
What is keratitis?
Inflammation of the cornea
What is HSV keratitis and what does it cause?
Inflammation of the cornea due to HSV
Causes a dendritic ulcer on the cornea
How do you diagnose a dendritic ulcer and how do you treat?
Fluorosccein drops will stain the lesion
Treat with acyclovir (avoid steroids as can cause corneal melt)
When to suspect orbital cellulitis and what to do?
Painful inflammation of the orbit, fever, lid swelling, decreased eye movements
Sinus CT and IV abx
`What is hutchisons sign and does it indicate?
Shingles on nose tip meaning involvement of the nasociliary branch of trigeminal nerve which supplies the globe thus eye likely to be affected
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