ophthalmology basics

Question 1

sensory innervation of upper eyelid

Answer 1

ophthalmic branch of the trigeminal

Question 2

sensory innervation of the lower eyelid

Answer 2

maxillary branch of the trigeminal

Question 3

a palsy of CNVII would show up on the eye as..

Answer 3

ectropion of the lower eyelid, NOT ptosis

Question 4

ptosis is cuased by

Answer 4

CN III palsy

Question 5

where is th lymph drianage of the eye

Answer 5

into periauricular and submandibular LNs

Question 6

what is conjunctiva

Answer 6

a mucous membrane lining the eyelids and covering the anterior eyball up to the edge of cornea.

Question 7

cornea and sclear structurally do what

Answer 7

form a spherical shell that makes up the outer wall of the eyeball

Question 8

what is the limbus?

Answer 8

the junction between the cornea and the sclera. contains stem cells that regenrate the corneal epithelium.

Question 9

how does aqueous humour drain and enter the eye

Answer 9

it circuates from posterior to anterior chamber through the pupil, leaves the eye through trabecular meshwork. this is a specialised tissue in the anterior chamber angle between the iris and the cornea. from there aqueous drains into Schlemm’s canal and then into veins.

Question 10

vitreous is what

Answer 10

99% water but also collagen fibrils, hyaluronan, which create cohesion and gel-like consistency.

Question 11

muscarinic stimulants

Answer 11

pilocarpine

increase aqueous outflow via trabecular meshwork by constricting the ciliary muscles

Question 12

alpha2 stimulants

Answer 12

brimonidine

reduce aqueous secretion by stimulating alpha2 receptors

Question 13

carbonic anhydrase inhibitors

Answer 13

acetazolamide, dorzolamide

reduce aqueous secretion by ciliary body

Question 14

prostaglandin derivatives

Answer 14

latanoprost

increase the aqueous flow by uveoscleral route

Question 15

mydriatics and cycloplegics

Answer 15

antimuscarinics: tropicamide, cyclopentolate, atropine

inihiobit muscarinic receptors and paralyse pupillary sphincter muscle and ciliary muscle

Question 16

alpha stimulants

Answer 16

phenylephrine

stimulates dilator muscle, no cycloplegic effect

Question 17

small hypermetropic optic disc is a risk factor for what?

Answer 17

non-arteritic anterior ischaemic optic neuropathy

Question 18

nAION presents like what?

Answer 18

painless monocular sudden loss of vision

Question 19

most common visual field defect with nAION

Answer 19

inferior altitudinal defect - corresponds to the swollen area of the optic disc

Question 20

polymyalgia rheumatica is associated with what?

Answer 20

GCA

Question 21

risk factors for acute angle closure glaucoma

Answer 21

Hypermetropia
FHx
narrow anterior chamber angles
>30 y/o
Asian race
Females