Amblyopia

Question 1

is amblyopia preventable?

Answer 1

if detected early enough we can prevent or reverse.

Question 2

how do we get amblyopia? does the eye appear abnormal?

Answer 2

it is acquired not congenital.

eye looks completely normal, it is in the back of the eye, the pathway has issues.

Question 3

amblyopia is more than just blur, what else occurs?

Answer 3

reduced and variable accommodation
abnormal eye movements
poor spatial judgement
reduced depth perception
reduced contrast sensitivity
possible pupil problems

Question 4

what is binocular summation?

Answer 4

both eyes work better together then each eye individually

Question 5

what is the critical period for amblyopia?

Answer 5

3-4 months and slowly declines around 6-8 years old.

Question 6

when is it best to catch amblyopia?

Answer 6

the quicker you catch it (younger age) the better chance of treatment. it will be more flexible and modifiable whereas in older people they loose plasticity.

Question 7

common definition of amblyopia?

Answer 7

unilateral (rarely bilateral) in which BCVA is poorer than 20/20 in the absence of any obvious structural or pathologic anomalies.

Question 8

diagnosing exclusion vs. inclusion for amblyopia. how do you exclude? include?

Answer 8

can rule out ocular pathology as cause of decreased VA by completing internal and external health evaluation and DFE.
must be able to explain the potential cause of amblyopia (RE, strabismis etc).

Question 9

what is amblyogenic strabismus?

Answer 9

constant, unilateral and present before age 7. watch for sensory XT: reduced VA is secondary to a pathology that may be causing an eye to drift out.

Question 10

define anisometropia. define isoametropia.

Answer 10

significant difference in RE between two eyes.

significant bilateral RE.

Question 11

what is amblyogenic astigmatism?

Answer 11

blurs visual stimuli in a specific orientation depending on the RE and axis.

Question 12

most amblyopia will result in acuity loss in the range of? any differences with strabismic amblyopia? is NLP or LP due to amblyopia?

Answer 12

20/30 to 20/100.
can be a little worse (20/200 or rarely 20/400)
NO

Question 13

once amblyopia is treated, what do you expect?

Answer 13

things to get better. if they dont it could be due to 1. incorrect diagnosis 2. wrong Rx 3. compliance. amblyopes should NEVER get worse.

Question 14

what do you look for in patients prescription to look for amyblopic risk?

Answer 14

difference between power in each eye. if over limit they may be at risk depending if they are in the critical period.

Question 15

when amblyopes read the VA chart, what is unique and should be considered?

Answer 15

they read a couple letters wrong across a large range of acuities due to crowding. they see better when things are isolated i.e. isolated to a line or just to one letter (best situation). therefore they do better with more spacing.

Question 16

we use the isolated letter with amyblopes to get a prediction of what?

Answer 16

their VA after treatment.

Question 17

what is form deprivation amblyopia?

Answer 17

there is a physical obstacle to visual stimuli. most severe but rarest.

Question 18

common treatment for amblyopia?

Answer 18

1. rx

2. occlusion (eye patch)

Question 19

hyeropes accommodate to what?

Answer 19

the least hyperopic eye

Question 20

what is the purpose of the occlusion treatment for amblyopes?

Answer 20

to force the use of the non dominant eye.

Question 21

what is strabismus under binocular conditions?

Answer 21

the fovea of one eye is looking in a different place than the fovea of another.

Question 22

why does strabismus occur?

Answer 22

something breaks down fusion (what?)

1. idiopathic
2. sensory
3. motor

Question 23

typical complaints of strabismic patients?

Answer 23

1. comfort
2. cosmesis
3. concern

Question 24

esotropias can be what sizes? exos? verticals? at what point do they become cosmetically significant?

Answer 24

esos can be small, moderate and large
exos moderate or large
verticals usually small. 
esos: 15PD
exos: 9PD

Question 25

strabismus can be classified in what three things?

Answer 25

frequency (constant or intermitant)
lateral (always right, left or alt)
comitancy (comitant= equal in all positions of gaze, non comitant change in magnitude of >5PD in one particular gaze). non more likely caused by pathology

Question 26

can strabismus always be seen? same at distance and near?

Answer 26

NO

can differ

Question 27

esotropias bigger at distance than near are often due to what? opposite?

Answer 27

neurological issues.

accommodative issues.

Question 28

strabismus that occurs when the visual system is immature (<6-8 years) will likely result in? in mature system?

Answer 28

immature: suppression, monofixation syndrome or anaomalous retinal correspondence
mature: diplopia, closes an eye, visually ignore, head posture