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Flashcards in Eye Review (core) Deck (33)
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1

What is normal IOP?

10-21mmHg

1

How does the cup to disc ration change in glaucoma?

It increases

2

Where does the optic nerve decussate in the brain to cause the consenual response?

Pretectal nucleus

3

What is the common cause of an altitudinal defect

Anterior ischaemic optic neuropathy

4

Which viral infection can effect the corneal reflex?

Herpes

5

What test do you use to evaluate macula function?

Amsler grid

7

What are leukocoria? What can it indicate?

White pupil

Retinablastoma, cataract, retinal detachment

7

What are some common causes of 4th nerve palsy?

Trauma

Tumour

Vasculitis

Can be congenital

9

How can you test the IOP?

Tono-pen

Glodmann Applanation tonometry

10

What causes an arcuate scotoma?

Glaucoma

11

What are three ways diabetic retinopathy causes vision loss

Macula oedema

Vitreous detachment

Retinal haemorrhage

12

What is the normal physiological cup to disc ratio?

0.5

13

What causes painfull third nerve palsy?

Aneurysm (Post comm art.) 

 

14

What is the pathophysiology of retinal detachment?

Separation of the inner layers of the retina from the underlying retinal pigment epithelium due to a number of mechanisms

- A tear in the neuronal layer allowing entry of vitreous fluid

- Traction from inflammation or vascular fibrous membranes on the surface of the retina

- Exudation of materials into the subretinal space such as due to HTN, central retinal artery occlusion, vasculitis, or papilloedema

15

How do you test light saturation?

Compare the appearance of light shined in each eye

16

Which muscle controls the pupils?

Sphincter pupillae

17

Which nuclei are involved in the pupil reflex?

The pretectal nucleus

The Edinger-Westphal nucleus

18

What is Agyll-Robertson pupil? What causes it?

A pupil that constricts to accomodation but not light

 

Classically neurosyphilis

Also diabetic neuropathy

 

19

What does a Holmes Adie pupil look like?

Tonically dilated pupil that doesn't response to light

20

How does internuclear ophthalmoplegia present? What is the mechanism? In which disease is it common?

Failure of abduction of one eye when laterally gazing to its contralateral side and concurrent nystagmus of the other eye. Convergence is maintain

 

Lateral gaze is controlled by the nucleus of CNVI on the ipsilateral side that the gaze is toward. Its signal to the ipsilateral lateral rectus is normal therefore abduction is possible on that side. Abduction of the other eye requires signal transmission from the CNIV nuclei to the contralateral CNIII nuclei (and subsequent CNIII innervation of the medial rectus). The medial longitudinal fasciculus transmits between CNVI and CNIII. In INO the MLF is disrupted.

 

Convergence is retained as it doesn't require the lateral rectus (and hence CNVI)

 

MS

21

What is myopia? What do they have trouble with? What type of correction do they use?

Light is focus before the retina - Short sightedness

 

Deficit - Think short sighted meaning can seeing objects at a short distance therefore have trouble with seeing objects at distance eg road signs

 

Biconcave lens

22

What hypermetropia? What do they have trouble with?

Light is focused beyond the retina - Long sightedness

 

Deficit: Long sighted meaning able to see things at a distance therefore trouble with focusing at close objects eg reading

 

Biconvex lens

23

What is astigmatism?

The cornea has irregular degrees of curvature

24

What is a presbyopia?

A form of hypermetropia due to loss of lens elasticity with age

25

What is primary open angle glaucoma? How does it present? How is it Mx?

Chronic, progressive optic neuropathy with open anterior chamber angles, and elevated IOP

 

Progressive visual field loss, progressive increase in cup to disc ratio and elevated IOP

 

Prostaglandin, timolol eye drop

Oral acetazolamide 

Surgery

26

Outline the grading system of non-proliferative diabetic retinopathy

Mild - Microaneursyms

 

Moderate - Microaneursyms

- Cotton wool spot

- Hard exudates

- Intra-retinal haemorrhages

 

Severe - any one feature of the 4-2-1 rule

- Intra-retinal haemorrhages in 4 quadrants

- Venous beading in 2 quadrants

- Intra-retinal vascular abnormalities in 1 quadrant

 

Very severe - 2 features of the 4-2-1 rule

27

Outline the types of proliferative diabetic retinopathy

Low risk - neovascularisation in <1/3 of the disc

 

High risk - Neovascularisation of disc + vitreous haemorrhage

- >1/3 of NVD

- Neovascularisation everywhere

28

How is proliferative diabetic retinopathy Mx?

Pan-retinal photocoagulation - peripheral vision sacrificed

 

VEGF inhibitors

29

What is the pathophysiology of dry aged related macular degeneration? How is it Mx?

Degeneration of the retina and choroid in the posterior pole either due to atropy or detachment of the retinal pigment epithelium. Preceded by the presence of drusen desposition at the basal RPE

 

Smoking cessation

Low vision aids

30

What is the pathophysiology of wet macular degeneration? How is it mx?

Proliferation of vasculature between the choroid and retinal pigment membrane which leaks and bleeds causing macular scarring

 

VEGF inhibitors

Photodynamic therapy