Refractive Amblyopia Flashcards
T/F Amblyopia is a condition where VA is reduced in one or both eyes
False; it may be a disease process, not necessarily amblyopia
T/F Amblyopia is a reduced VA
False; may be a disease process
T/F Amblyopia is a syndrome
False; not everyone with the condition shares the same signs and symptoms
A _____ is the association of several clinically recognizable features (observed by physician) and symptoms (reported by patient) that often occur together.
syndrome
What visual skills can be affected by amblyopia
- VA
- CS
- Accommodation
- Pursuits
- Depth perception
The _____visual pathway is affected the most by amblyopia
parvo
Functional amblyopia is a unilateral or infrequently bilateral condition in which the BCVA is poorer than 20/20 in the bases of any obvious structural or pathologic anamolies, but with one or more of the following conditions occurring before the age of _____yo:
6: 1. signifiant anisometropia 2. significant isoametropia 3. significant unilateral or bilateral astigmatism 4. constant unilateral eso/exotropia 5. image degradation (corneal edema, ptosis, cataracts)
what is the prevalence of amblyopia
2-3% of the population have it
When one eye has amblyopia and the other eye is unaffected, which eye be will be damaged more?
The “good eye” will experience more damage bc that is the better seeing eye which is used more.
Prevalence is not affected by gender, but in some series, the ____ eye was more commonly affected than the right, particularly in cases of anisometropic amblyopia
left
What is Sherman’s behavioral definition of amblyopia
- Amblyopia is a dysfunction that restricts the ability to gather, process, analyze, and respond to visual info.
- Amblyopia is a problem primarily of binocular competition. The reduction of monocular VA is merely the presenting symptom.
What are some risk factors of amblyopia?
- Prematurity
- LBW
- Retinopathy of prematurity
- Cerebral palsy
- Mental retardation
- Family history of anise, isoametropia, strabismus, amblyopia, or congenital cataract.
The risk for amblyopia also increases four fold following _____ surgery for early onset esotropia. The brain has already developed retinal correspondence based on esotropia. Changing the EOM alignment will change the retinal correspondence.
EOM
Amblyopia is classified into organic amblyopia and functional amblyopia. Describe each.
Organic: cases of reduced vision where ocular pathology is the cause.
Functional: cases of reduced vision where a functional etiology is the cause.
______amblyopia is characterized by a decrease in VA and a deficient performance of the visual system not due to an obvious structural /pathologic anamolies and it can’t be corrected with a refractive rx
Refractive –> anisometropia or isoametropia
With ______amblyopia, most frequently central fixation is present but is unsteady. Myopia anisometropia is more prevalent in the population BUT amblyopia is more prevalent in _____ aniso.
anisometropic, hyperopic
Suppression is usually less deep in anisometropic amblyopia than in ______amblyopia
strabismic
Isometropic amblyopia presents with better ____ than anisometropic amblyopes. What are characteristics of isometric amblyopia?
stereopsis
- central fixation is present but unsteady.
- bilateral
- corrective lenses improve acuity beyond the uncorrected level but not to 20/20.
- Most frequent in bilateral high hyperopia
How much myopic anisometropia will increase the risk for amblyopia?
> -3.00 and -5.00
How much hyperopic anise will increase the risk for amblyopia?
between +1.00 and +2.00
How much astigmatic anise will increase the risk for amblyopia?
between -1.00 and -2.00
What are signs of parvo (what) system being affected
- difficulty of visually tracking/following objects
- loss of place
- need to utilize marker to avoid loss of place
- frequent transpositions when copying from one place to another.
- abnormal posture
- inaccurate work product
- reduced efficiency
what are symptoms of parvo( what) pathway
- visual field neglect
- asthenopia
- inconsistent visual attention
- increased distractibility
- difficulty sustaining near visual function
- abnormal general fatigue
- dizziness/vertigo
- motion sickness
- incoordination clumsiness
- inaccurate eye hand coordination
T/F in amblyopia sysmptoms are caused by the good eye
true; when starting VT, you need to focus on addressing issues associated with the better seeing eye. The bad eye is not functioning so it is not the cause of the symptoms.
what are diagnostic factors for amblyopia?
- Reduced VA monocular or binocular
- relative high isoametropia
- anisometropia
- suppression of binocular vision
- reduced stereopsis
- accommodative disorder
(amblyopic is always out of focus, blur from amblyopic eye no longer stimulates accommodation) - deficient saccadic/pursuit eye movements
- inaccuate/eccentric foveal fixation
- spatial uncertainty; poor spatial localization –> incoordination
- anomalous eye movements
- increased effects of crowding
- increases saccadic latency and reduced saccadic accuracy.
- depressed C/S
- poor speed and span of recognition
- faulty eye hand coordination
Treatment outcome is not related to age, but to better baseline ____ and lesser amounts of anisometropia. Experimentally induced blur during dev leads to a selective loss of neurons tuned to ____ spatial frequencies.
VA; high
