lecture 4 abnormal visual development amblyopia Flashcards
Which 2 criteria do you base an amblyopia diagnosis on?
exclusion and inclusion
(T or F) amblyopia is a monocular condition only
false, it can be monocular or binocular
Which statement about amblyopia is correct:
A) Amblyopia is pathological condition that causes visual acuity loss
B) Amblyopia is condition where one or both eyes are worse than 20/20 corrected in the absence of disease
C) Amblyopia is a developmental anomaly of spatial vision in which a person can have 20/20 vision despite having an ocular disease
D) Ambyopia happens when ocular dominance columns fail to properly form
B) Amblyopia is condition where one or both eyes are worse than 20/20 corrected in the absence of pathology/disease
(T or F) ambloyopia is preventable
true
Your patient has 20/50 V.A. in OD and 20/80 in OS best corrected. You decide not to dilate your patient since there is no apparent signs of disease based on your slit lamp findings. You diagnose your patient with amblyopia. why is this wrong?
amblyopia diagnosis has 2 parts. first, the pt must have worse than 20/20 best corrected without any signs of disease therefore you MUST dilate this pt to rule this out. second, amblyopia is always associated with strabismus, anisometropia, or image deprivation or a combination of all 3.
Which of the following would you not expect to find in an amblyopic patient?
A) reduced contrast sensitivity and visual resolution
B) increased sensitivity to contour interaction effect (crowding)
C) steady and accurate monocular fixation
D) abnormal spatial distortions
C) steady and accurate monocular fixation (they would have unsteady and inaccurate fixation)
What are the 4 types of amblyopia?
refractive, strabismic, form deprivation, idiopathic
(T or F) refractive amblyopia can be either anisometropic or isometropic
true
What is the cause of idiopathic amblyopia?
idiopathic means that the cause is unknown
Which are the 2 most common forms of amblyopia?
A)strabismic and form deprivation,
B) idiopathic and isometropic
C) form deprivation and idiopathic
D) strabismic and anisometropic
D) strabismic and anisometropic (together they account for more than 90% of all amblyopia cases) *these two are also the less severe of all, these types do not cause structural changes in cortex and LGN, there is less profound loss in contrast sensitivity and better VA (strabismic:20/60-20/80, anisometropic:>20/60)
which form of amblyopia is the most severe?
A) form deprivation
B) idiopathic
C) strabismic
D) refractive
A) form deprivation (it causes morpholohical neuronal changes in the cortex and LGN due to inter-ocular inhibition)
- VA ~20/400
- worst constrast sensitivity
monocular congenital cataracts can cause which type of amblyopia if not treated quickly?
monocular form deprivation (if removed at 4-6 months of age, va will be 20/400) * must be removed before 2 months
(T or F) Meridional amblyopia develops relatively late due to the presence of astigmatism over a period of years.
true
Which one of the following cover test result in a 5 year old patient will suggest a risk for developing strabismic amblyopia?
A. Constant alternation (OD 50%, OS 50%) exotropia at distant and near
B. Constant left esotropia at distance and near
C. Intermittent (30% of the time) right esotropia at distance and near
D. Constant left esotropia at distant, constant right esotropia at near
B. Constant left esotropia at distance and near
Which one of the following scenarios is not a possible prognosis for a 6 year old patient with refractive error of +5.50D OU that had never been corrected before?
A. Monocular form deprivation amblyopia
B. Bilateral Isometropic refractive amblyopia
C. Normal vision
D. Accommodative esotropia with amblyopia in the turned eye
A. Monocular form deprivation amblyopia
Which one of the following factors does not affect the degree of crowding?
A. Separation between the characters B. Location in the visual field C. Color of the characters D. Character size
C. Color of the characters
Which one of the following statement is incorrect?
A. Only monocular form deprivation amblyopia will show ocular dominance column shrinkage in the primary visual cortex.
B. Strabismic and refractive amblyopia will show contrast sensitivity loss in high spatial frequency.
C. Strabismic and refractive amblyopia also shows primary visual cortex and LGN structural changes.
D. The ocular dominance histogram of a monocular form deprivation amblyopia will show complete shift towards column 7.
C. Strabismic and refractive amblyopia also shows primary visual cortex and LGN structural changes.
Which one of the following scenario might cause the most severe amblyopia?
A. A patient with refractive error of +8.00 D OU
B. A patient with binocular cataract that was removed at the age of 5 months.
C. A patient with constant unilateral infantile esotropia (onset around 6 months) at distance and near.
D. A patient with monocular cataract that was removed at the age of 5 months.
D. A patient with monocular cataract that was removed at the age of 5 months.
A 4 years old patient with which one of the following refractive error is not at risk for developing amblyopia?
A. OD: +1.75-0.50X110; OS: +5.25-0.75X098
B. OD: -0.50 -3.25X167; OS: -1.25-3.75X173
C. OD: -1.50-1.00X183; OS: -2.25-1.50X175
D. OD: +6.75-1.25X180; OS: +6.25-0.75X005
C. OD: -1.50-1.00X183; OS: -2.25-1.50X175
Which one of the following will show nasal/temporal asymmetric visual acuity loss?
A. Isometropic amblyopia
B. Strabismic amblyopia
C. Bilateral form deprivation amblyopia
D. Anisometropic amblyopia
B. Strabismic amblyopia
(T or F) For young patients who have bilateral high hyperopia, accommodation and vergence system does not affect their risk of developing amblyopia.
False
A 5 years old patient with which one of the following refractive error is at risk for developing amblyopia?
A. OD: +0.50 -2.00X075; OS: -0.25 -1.25X089
B. OD: -6.00 -1.25X167; OS: -6.50 -0.75X173
C. OD: +3.00 -0.50X181; OS: +3.75 -0.75X012
D. OD: pl -0.75X098; OS: +0.50 -3.50X079
D. OD: pl -0.75X098; OS: +0.50 -3.50X079
Which one of the following scenario might cause the most severe amblyopia?
A. A patient with monocular cataract that was removed at the age of 5 months.
B. A patient with refractive error of +8.00 D OU
C. A patient with constant unilateral infantile esotropia (onset around 6 months) at distance and near.
D. A patient with binocular cataract that was removed at the age of 5 months
A. A patient with monocular cataract that was removed at the age of 5 months.
Which type of amblyopia will show ocular dominance column shrinkage in primary visual cortex:
A) monocular form deprivation
B) strabismic
C) refractive
D) idiopathic or refractive
A) monocular form deprivation
(T or F) Anisometropic amblyopia patients demonstrate unsteady and eccentric fixation
false
Which one of the following statement about aspect
effect is incorrect?
A. Crowding effect is a normal phenomenon in peripheral vision.
B. Amblyopia patient has abnormal crowding effect on their central vision.
C. Crowding effect does not affect an amblyopia patient’s ability to identify single letter on a visual acuity chart.
D. Crowding effect does not affect an amblyopia patient’s read speed.
D. Crowding effect does not affect an amblyopia patient’s read speed.
when identifying refractive amblyopia the astigmatism is ___ in anisometropic pts and is ____ in isometropic pts
A) >1.50D, >3.50D
B) >3.50D, 1.50D
C) >1.50D, >2.50D
D) >2.50D, >1.50D
C) >1.50D, >2.50D
when identifying refractive amblyopia the hyperopia is ___ in anisometropic pts and is ____ in isometropic pts
A) >1.50D, >5.50D
B) >3.50D, 1.50D
C) >1.00D, >5.00D
D) >8.00D, >1.00D
C) >1.00D, >5.00D
when identifying refractive amblyopia the myopia is ___ in anisometropic pts and is ____ in isometropic pts
A) >1.50D, >3.50D
B) >3.50D, >1.50D
C) >1.00D, >5.00D
D) >3.00D, >8.00D
D) >3.00D, >8.00D
Which scenario would a patient be more at risk of developing amblyopia?
A) 8D constant Left esotropia at distance
10D constant Right esotropia at near
B) 8D constant Left esotropia at distance
10D constant Left esotropia at near
B) 8D constant Left esotropia at distance
10D constant Left esotropia at near
this pt is probably seeing double which can lead to suppression and amblyopia
what 2 things could you do to prevent a strabismus from becoming amblyopia?
surgery or prism lenses
which type of amblyopia is the rarest?
isometropic (1-2% of all cases)
Which of the following is not a factor affecting crowding?
A) separation between characters
B) character size
C) perception of color
D) location in the visual field
C) perception of color
(T or F) amblyopic reading deficit is affected mainly by increased crowding effect rather than reduced VA
true
Fixation for anisometropic amblyopes is usually ____ and ____
A) central, stready
B) central, unsteady
C) eccentric, steady
D) eccentric, unsteady
B) central, unsteady
Fixation for strabismic amblyopes is usually ____ and ____
A) central, stready
B) central, unsteady
C) eccentric, steady
D) eccentric, unsteady
D) eccentric, unsteady
strabismic amblyopes usually have ____ to ____ eccentric fixation
A) 0.5 to 4 degrees
B) 1 to 5 degrees
C) 5.6 to 12.8 degrees
D) 25 to 40 degrees
A) 0.5 to 4 degrees
What is “Maxwell’s Spot”?
A) the center of the optic nerve that carries the highest electrical potential
B) the outermost portion of the optic nerve that carries the lowest electrical potential
C) The pigmented macular area that creates the entoptic phenomenon
D) the unpigmented macular area that does not create the entotopic phenomenon
C) The pigmented macular area that creates the entoptic phenomenon
(T or F) amblyopia appears to have no direct link with accomodative function
false, most amblyopic patients have reduced accomodation secondary to amblyopia
