Ch 3(Anat Of Uvea)

Question 1

What are the structures in the functional classification of uvea?
i.e.- Ant, intermediate and posterior uvea

Answer 1

Ant uvea- iris and pars plicata
Intermediate uvea- pars plana
Posterior uvea- choroid

Question 2

Ciliary body arises from which layer of uvea, and attached to what structure?

Answer 2

Arises from pars plicata,
And secretes aqueous humor
And attached to zonules which hold the lens

Question 3

Thickest part of iris?

Answer 3

Collarette- represents site of attachment of pupillary membrane

Question 4

Thinnest part of iris?

Answer 4

Root of iris

Question 5

Nerve supply of dilator pupillae?

Answer 5

Sympathetic supply by Long Ciliary Nerve

Question 6

Nerve supply for sphincter pupillae?

Answer 6

Parasympathetic (3,7,9,10)
By 3rd CN
The inferior branch which also supplies inferior oblique muscle-
SHORT CILIARY NERVE

Question 7

What is the popular name of oculo-sympathetic palsy?

Answer 7

Horner’s Syndrome

Question 8

Causes of sympathetic palsy at 1st order neuron?

Hypothalamus to ciliospinal budge

Answer 8

Brain stem lesions like tumor
Syringomyelia
Diabetic neuropathy
Wallenberg Syndrome

Question 9

Cause of 2nd order neuron palsy?

Ciliospinal budge to superior cervical ganglion in neck

Answer 9

Pancoast tumor
Carotid and aortic aneurysm
Neck lesions

Question 10

Causes of 3rd order neuron/ Post-ganglionic damage?

Ascends via cavernous sinus to dilator pupillae via long ciliary nerve

Answer 10

Cluster headache
Internal carotid artery dissection
Otitis media
Cavernous sinus mass

Question 11

Clinical features of horner’s Syndrome?

Answer 11

H- heterochromia iridis( in horner’s, the lighter colour iris is abnormal)
I- inferior eyelid elevation ( paralysis of inferior tarsal muscle)

M- miosis
A- anhydrosis( ipsilateral absence of sweating
P- ptosis( muller's muscle palsy)
L- loss of ciliospinal reflex
E- enophthalmos( sunken eyeball)

Question 12

Test for diagnosis of horner’s

Answer 12

4% cocaine test

Question 13

Test for localisation of the lesion

Answer 13

Amphetamine/ Adrenaline test

Question 14

If after amphetamine test also, Horner’s pupil doesn’t dilate, indicates to what site of lesion?

Answer 14

3rd order neuron/ Post-ganglionic nerve lesion

Question 15

Oculo-sympathetic overactivity seen in which syndrome?

Answer 15

Pourfour du Petit Syndrome ( opposite of horner’s)

Question 16

Causes of meiosis?

Hint- HICOPS

Answer 16

H- horner's synd, haemorrhage (pontine)
I- iridocyclitis
C- clonidine, carbolic acid
O- organophosphates, opioids
P- parasympathomimetics, phenothiazines, pilocarpine
S- sleep sedatives

Question 17

Causes of mydriasis?

Hint- BIG OATS

Answer 17

B- belladona poisoning
I- Internal Ophthalmoplegia
G- glaucoma ( ACG)

O- occulomotor nerve palsy
A- atropine
T- tonic pupil
S- sympathomimetics

Question 18

Function of ciliary body?

Answer 18

Accommodation

Secretion of aqueous

Question 19

Parts of near reflex?

Answer 19

Accommodation
Convergence
Meiosis

Question 20

State T/F
As part of near vision,ciliary muscle contracts.
Zonules are relaxed
This decreases power of lens
There is change in posterior curvature
Antero posterior diameter of lens increase

Answer 20

T
T
F- this increases power of lens
F- NO CHANGE IN POSTERIOR CURVATURE OCCURS
T

Question 21

Name 2 anomalies of accommodation

Answer 21

Presbyopia

Spasm of accommodation

Question 22

What is presbyopia?

Answer 22

Physiological insufficiency in accommodation after 40yrs of age

Question 23

What is the power of lens prescribed to a presbyopic at 55yrs of age?

Answer 23

At 45yrs- +1D to 1.25D
Every 5yrs, power increases by 0.5D
Thus at 55yrs- +2D to +2.25D

Question 24

What are monofocal lenses?

Answer 24

When person is emmetropic( No other defect in eye like myopia/hypermetropia etc)
Then he requires monofocal lenses

Question 25

Type of lens used in presbyopia when person already has a refractive error?

Answer 25

Either bifocal or progressive Bifocal can either be D shaped or executive bifocal. Progressive spects have no 2 foci like bifocal but a progressive increase in power.

Question 26

What is the pathology in spasm of accommodation? | It's t/t?

Answer 26

Ciliary muscle is permanently contracted, focus is always at near vision. It mimics myopia so k/a pseudomyopia. T/t is atropine

Question 27

What is Bruch's membrane?

Answer 27

Retino choroidal junction, made of 5 layers.

Question 28

``` Layers of Bruch's membrane are- Basement membrane of RPE .,....................... ......................... Outer collagenous layer BM of ........ ```

Answer 28

Inner collagenous layer Elastic tissue layer BM of choriocapillaris