Fundamentals of ophthalmology

Question 1

What questions would you ask if a patient presents with visual disturbance?

Answer 1

one or both eyes?
when did it start?
gradual or sudden?
where in vision?
double vision?
associated symptoms?
distortion?

Question 2

What questions would you ask if a patient presents with red eye?

Answer 2

one or both eyes?
discharge?
pain?
lacrimation?
blurred vision?
photophobia?
associated symptoms?

Question 3

What questions would you ask if a patient presents with eye pain?

Answer 3

SOCRATES

Question 4

How is visual acuity measured?

Answer 4

Snellen chart, 6m

numerator = distance 6m chart is read from
denominator = distance a person with normal eyesight could read the line from

Question 5

Describe the pinhole effect

Answer 5

pinholes eliminate all but straight beams of light which fall directly on the retina, giving a clear image

Question 6

How is colour vision assessed?

Answer 6

Ishihara colour charts

Question 7

What is hypermetropia?

Answer 7

long-sighted eye
image is focussed behind the retina
often a smaller eye than average

Question 8

How is hypermetropia corrected?

Answer 8

convex lens, converges the light to hit the retina

Question 9

What is myopia?

Answer 9

short-sighted eye
image focussed in front of retina
often a larger eye than average

Question 10

How is myopia corrected?

Answer 10

concave lens, diverges the light to hit the retina

Question 11

What does it mean if vision improves with pinhole?

Answer 11

refractive error and therefore needs glasses

if it doesn’t improve then the problem is not refractive, the problem is somewhere else in the eye

Question 12

Which cranial nerves allow oculomotility?

Answer 12

CN 3,4 + 6
eye will deviate if any of these are affected

Question 13

What happens if you shine a light in one pupil?

Answer 13

both pupils constrict

Question 14

What happens when you shine light on one eye, and there is a tumour on an optic nerve?

Answer 14

both pupils constrict

Question 15

What happens if you swing a light between pupils when there is a tumour on an optic nerve?

Answer 15

both pupils dilate
swinging flashlight makes brain think light has decreased, therefore pupil dilates

called relative afferent pupillary defect

Question 16

What is anisocoria?

Answer 16

difference in pupil size

Question 17

In dim light, would a larger or smaller pupil be abnormal?

Answer 17

smaller pupil

Question 18

In bright light, would a larger or smaller pupil be abnormal?

Answer 18

larger pupil

Question 19

Horner’s syndrome signs

Answer 19

(PAMELa)
Ptosis
Anhydrosis
Miosis
Enophthalmos
Loss of ciliospinal reflex

Question 20

What happens in Horner’s syndrome if 4% cocaine is added?

Answer 20

normal pupil dilates
Horner’s pupil does not dilate (loss of sympathetic tone)

cocaine does not have an effect on Horner’s

Question 21

What happens in Horner’s syndrome if 1% hydroxyamphetamine is added?

Answer 21

pre-ganglionic = both pupils dilate
post-ganglionic lesion = Horner’s pupil does not dilate

Question 22

What happens in Horner’s syndrome when 1:1000 adrenaline is added?

Answer 22

pre-ganglionic lesion = both pupils do not dilate
post-ganglionic lesion = Horner’s pupil will dilate

Question 23

What happens in Horner’s syndrome when Apraclonidine (0.5% or 1% is added)?

Answer 23

no effect on normal pupil
(upregulatin of alpha-1 receptors - denervation hypersensitivity)
Horner’s pupil dilates

Question 24

What should you comment about the optic nerve on fundoscopy?

Answer 24

colour
contour
cup-to-disc ratio

Question 25

Where do all the blood vessels meet on the retina?

Answer 25

Optic nerve/disc