Introduction to Amblyopia Flashcards
(42 cards)
“Lazy eye” is also known as what?
Amblyopia.
True or False: Amblyopia is the functional loss of vision attributable to pathology.
False. Not attributable to pathology.
What age does amblyopia usually develop?
Age 6-8 and may persist for life once established.
In an amblyopic eye, brain receives 2 images, one clear and one blurred. This is also known as what? What mechanism occurs afterwards?
Anisometropia. Brain wants one clear image so the eye with the best picture wins and the the eye with worst picture turns off.
What three problems does amblyopia cause with binocular vision? What other problem does amblyopia cause?
Poor eye tracking, poor accommodative response, and suppression of one eye. Also loss of depth perception (3-D)
True or False: Amblyopia is a reduction in VA to 20/30 or worse in one eye or a two line difference between the two eyes.
True.
True or False: For amblyopia to exist, the visual pathway does not develop normally because of inadequate stimulation.
True.
Amblyopia is a major cause of loss in vision in what age group?
Under 45 year age group.
Amblyopia affect approximately what percention of the population in the US?
2%.
What are some causes of amblyopia? (Name 4).
Form deprivation, optical defocus (anisometropia, meridional, isoametropia which is equal but large refractive error), strabismus or eye turn.
Physical obstruction along the line of sight is called what? Name some examples of this.
Form deprivation. Congenital cataracts; congenital ptosis; Traumatic cataracts; Corneal opacities.
When does form deprivation usually occur?
Before age of 8 to cause amblyopia.
The degree to which amblyopia develops depends on what?
The time of onset and the extent of the form deprivation.
True or False: Form deprivation allows for clear, sharp images to reach the retina.
False. Prevents a clear, sharp image from reaching the retina.
Refractive amblyopia (or optical defocus) has three main categories. What are they?
Anisometropic, meridional, and isoametropic.
What is defined as an unequal refractive error between the two eyes, usually more than 1.00D difference?
Anisometropic refractive amblyopia.
Which refractive problem can tolerate a larger amount of anisometropia without a reduction in the VA?
Myopia OU.
True or False: Myopic patients may not have as severe an amblyopia even with 5.00D of anisometropia.
True.
Amblyopia will occur sooner in which refractive condition?
Hyperopia OU.
True or False: Hyperopic patients will not demonstrate amblyopia with just 1.00D of anisometropia.
False. Patient may demonstrate amblyopia with even 1.00D of anisometropia.
A general rule for amblyopia is that the more severe the ___________, the more severe the ___________, and the worse the __________.
Anisometropia, amblyopia, visual acuity.
Uncorrected high astigmatism OU is referred to as what?
Meridional refractive amblyopia.
Amblyopia will not usually occur until there is at least ____D to ___D of uncorrected astigmatism.
1.50, 2.00D.
High degrees of ametropia in both eyes is referred to as what?
Isoametropic refractive amblyopia.
