Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
98 Cards in this Set
- Front
- Back
|
true or false
Prevalence of myopia increases markedly during school years. |
true
-once the child becomes myopic, conditions tend to progress rapidly for a period of several years |
|
|
why is there a shift in myopia in older populations (60+ years)?
|
secondary to nuclear sclerotic cataracts
|
|
|
According to Donders classification of myopia, is based on?
|
result of prolonged use of eyes for close work
|
|
|
according to Curtin classification of myopia, it is based on?
|
etiology, degree of myopia and time of onset
|
|
|
Borish classification of myopia is based on?
|
dioptric magnitude
|
|
|
According to Borish classification, what is a medium myope? very high?
|
Medium: 3.00-6.00D
Very high: >10.00D |
|
|
What is Sorsby classification of myopia based on?
|
relationship between components and refraction
-Pl.-4.00D: components of the eye are in same range as an emmetropic eye ->4.00D: component refractive error where axial length was beyond range of the emmetropic eye |
|
|
what is a cause of posterior staphyloma? what is it/
|
Myopia
-ectasia of sclera causing recession of the sclera at optic nerve |
|
|
Can myopia be associated with retinal detachment?
|
yes
|
|
|
Does optical defocus via plus or minus lenses cause compensatory changes in eye growth and refractive state?
|
yes
|
|
|
When does prevalence of myopia increase sharply?
|
During childhood and adolescence
|
|
|
True or false
GP wear slows myopia progression. |
false
-rigid lenses do not slow myopia progression CLAMP |
|
|
True or false
SCL causes more myopic progression than spectacle lens wear. |
False
-SCL do not cause more myopic progression than spectacle lens wear, however it does not inhibit myopic progression ACHIEVE |
|
|
True or false
Undercorrection slows the progression of myopia |
False
-undercorrection does not slow the progression of myopia |
|
|
true or false
PAL should not be routinely prescribed for myopia control |
True
COMET study |
|
|
True or false
-Atropine is routinely used to slow progression of myopia in children over 2 years old |
false
-although effective, atropine is not routinely used to slow progression of myopia due to side effects |
|
|
True or false
Vision training slow the progression of myopia |
false
-VT does not slow progression of myopia, additional research pending |
|
|
True or false
The LORIC study determined that corneal reshaping shows promise in myopia progression control. |
True
Ortho K- |
|
|
true or false
"add" power is plus lenses prescribed over the distance manifest refraction |
true
|
|
|
What group is likely to show earlier onset of presbyopia?
|
patients with short arms, hyperopes
|
|
|
Smaller aperture gives greater/lesser depth of focus.
|
greater
|
|
|
What does BCC or FCC measure in patients with presbyopia?
|
patients lag of accommodation
-THIS IS THE MAX PLUS PT. WILL ACCEPT -the most a patient can relax their accommodation |
|
|
You measure your patients working distance at 40cm, AA=2D, what is the add?
|
2.5D-1D=1.5D Add
reading add=working dist. - 2/3 (or 1/2) of AA |
|
|
Your patient is 50YOM. assuming this patient meets Hoffstetter's age expected amplitude, what is your recommended add power using 1/2 of the AA at 33cm working distance?
|
18.5- 50(.33)=3.5D AA
33cm= 3D +1.25 add |
|
|
How is NRA/PRA used to find a patients add power?
|
average the two findings (NRA+PRA)/2
-add power will be balanced between the two values |
|
|
Using NRA/PRA, what is the add power for the following patients findings. NRA: +2.50, PRA: +2.00
|
2.5+2.0= +4.5D
4.5/2= 2.25D of ADD |
|
|
what is the tentative add of a patient who is 45 years old?
|
+1.00
|
|
|
what is dynamic retinoscopy used for?
|
retinoscopy at near working distance
|
|
|
Which would have a higher add power, closer/farther working distance?
|
closer working distance
-closer work requires more accommodative power |
|
|
what is the standard distance for all near phoropter testing?
|
40cm
|
|
|
You complete your phoropter testing and determine your patients needs at +1.50 ADD at 40cm. The patients working distance when sewing is 20cm.
What is the add power needed? |
-Accommodative demand at 40cm= 2.5D
-accommodative demand at 20cm= 5.0D 5.0-2.5=2.5D greater accommodative demand at 20cm -1.50+ +2.50=+4.00D ADD |
|
|
Your patient wants a pair of single vision near reading glasses to sew with. her manifest refraction is
OD: -2.50 -0.50 x 180 OS: -2.25 DS ADD: +4.00 What should you prescribe? |
OD: +1.50 -0.50 x 180
OS: +1.75 DS |
|
|
If you increase add, it increases or decreases depth of focus?
|
decreases
-higher add reduces range of clear vision |
|
|
Would modifying distance refraction change the effective add power?
|
yes
|
|
|
Habitual Rx: OD: PL DS, OS: PL DS, ADD: +2.5
Manifest Rx: OD: +0.5 DS, OS: +0.5 DS, ADD +2.5 What is the patients effective add in her habitual Rx? |
+2.50 -0.5= +2.0
|
|
|
What is compound myopic astigmatism?
|
CMA: bot meridians focus in front of the retina
|
|
|
Define simple myopic astigmatism.
|
one meridian focuses at the retina and the other in front of the retina
|
|
|
Define mixed astigmatism.
|
One meridian focuses in front of the retina and the other behind the retina.
|
|
|
What is the classification of an astigmatism, with one meridian on the retina and the other behind the retina?
|
Simple hyperopic astigmatism
SHA |
|
|
What is the classification of an astigmatism, with both meridians behind the retina?
|
Compound hyperopic astigmatism (CHA)
|
|
|
The steeper meridian will have a longer or shorter radius of curvature?
|
shorter
|
|
|
Define symmetrical astigmatism.
|
Sum of the axes in both eyes equals 180˚
|
|
|
OD: 43.5/170
OS: 45.0/090 What type of astigmatism is seen between the two eyes? |
heteronymous astigmatism
|
|
|
What are common symptoms of spherocylindrical lenses and adaptation?
|
-distortion
-tilted floor and walls -funny appearance of objects -alteration in shape of ocular image |
|
|
Which type of astigmatism typically has more complaints of decreased VA? WTR or ATR.
|
ATR
-bc we live in a vertically oriented world -in ATR, there is more refractive error horizontally, so vertically oriented lines will be less clear |
|
|
High amounts of uncorrected astigmatism lead to the potential risk of?
a. meridional amblyopia b. amblyopia c. astigmatic amblyopia |
A. meridional amblyopia
|
|
|
Why would a patient who objectively shows high amounts of cylinder, subjectively reject it all?
|
they have learned to compensate and have become used to their habitual focus and perceptions
|
|
|
Topical cycloplegic agents work primarily on which portion of the nervous system?
|
parasympathetic
|
|
|
Topical cycloplegics are drugs that paralyze the ciliary muscle. What do they block?
|
block muscarinic receptors that are normally stimulated by ACh
|
|
|
what medication is most commonly used to dilated a patient for fundus exam?
|
tropicamide
|
|
|
What medication is most commonly utilized to perform cycloplegic refractions?
|
cyclopentolate
|
|
|
True or false
A child with constant or intermittent esotropia is an indication for cycloplegic exam. |
true
|
|
|
True or false
A patient with hyperopia and exophoria is an indication for cycloplegic exam. |
False
-A patient with myopia and esotropia |
|
|
What type of hyperopia is "hidden" due to constant accommodation?
|
Latent hyperopia
|
|
|
What examination technique is required to fully assess the amount of latent hyperopia
|
cycloplegic refraction
|
|
|
What is pseudomyopia?
|
inaccuracy of accommodative excess (accommodative spasm) which causes the patient to appear myopic
-alternately: nearsightedness that rapidly increases second to underlying causes (medication, DM, myasthenia gravis) |
|
|
A pseudomyopic patient will show, a lead/lag of accommodation on FCC?
|
lead
|
|
|
What are causes of accommodative spasm?
|
-overstimulation of accommodative system, prolonged near work
-emotional problems -excessive accommodation to overcome convergence problems |
|
|
Which topical mydriatic has the fastest onset and shortest duration of cycloplegic effect?
|
cyclopentolate
|
|
|
Would a dark/light pigmented eye require more topical cycloplegic agent?
|
Darkly pigmented eyes.
-readily bind to medication reducing bioavailability |
|
|
What topical cycloplegic agent is standard care for testing uveitis?
|
homotropine
|
|
|
Which topical cycloplegic agent has the fastest onset and shortest duration of mydriatic effect?
|
tropicamide
|
|
|
What is simple hyperopia?
|
hyperopia due to normal biological variation
|
|
|
Which type of hyperopia is caused by abnormal ocular anatomy due to maldevelopment, ocular disease or trauma?
|
pathological hyperopia
|
|
|
What type of hyperopia results from paralysis of accommodation?
|
functional hyperopia
|
|
|
Hyperopes accommodate at near/distance?
|
both distance and near
|
|
|
List and define the two types of simple hyperopia.
|
Axial hyperopia: shorter than normal length with normal corneal curvature
Refractive hyperopia: normal length with flatter than normal corneal curvature |
|
|
what is asthenopia?
|
eyestrain
|
|
|
True or false
High hyperopia is associated with increased risk of amblyopia and strabismus |
True
this is a major justification for early vision exams |
|
|
List 3 signs and symptoms of hyperopia
|
asthenopia
focusing problems red or tearing eyes squinting and facial contortions while reading ocular fatigue difficulty reading/aversion to reading |
|
|
What study showed that rigid lenses do not slow myopia progression.
|
CLAMP
|
|
|
Which study determined that SCL do not cause more myopic progression than spectacle lens wear, however it does not inhibit myopic progression.
|
ACHIEVE
|
|
|
Which study determined that PAL should not be routinely prescribed for myopia control.
|
COMET
|
|
|
Which study determined that although effective, atropine is not routinely used to slow progression of myopia due to side effects.
|
ATOM
|
|
|
Which study determined that corneal reshaping shows promise in myopia progression control.
|
LORIC/CRAYON
|
|
|
In premature infants what it is the cause of myopia?
|
underdevelopment of the eye, the cornea is steep
|
|
|
Eye that are not completely developed at birth tend to be more_______.
a. myopic b. hyperopic c. emmetropic |
a. myopic
|
|
|
What are the three classifications of Curtin's classification of myopia?
|
-physiologic: simple myopia. failure between refracting power of eye and axial length
-intermediate: medium/mod. myopia. expansion of posterior seg. of globe -pathological: ocular disease associated with elongation of eye.. |
|
|
True or false
Patient with > 8.0D of myopia have a greater risk of presenting with pathology. |
true
|
|
|
Subretinal neovascularization is associated with.
a. myopia b. hyperopia c.emmetropia |
a. myopia
|
|
|
NRA stimulates/relaxes accommodation.
|
relaxes accommodation
|
|
|
NRA is an indirect measure of convergence/divergence.
|
convergence
|
|
|
In NRA and PRA, if mergence is allowed to move with accommodation, what will occur?
|
diplopia
|
|
|
PRA stimulates/relaxes accommodation.
|
stimulates accommodation
|
|
|
What happens when a patient stimulates accommodation?
|
increase in accommodative convergence
|
|
|
What is PRA an indirect measure of?
|
divergence
|
|
|
True or false
The amount of plus sphere added in NRA, indicates the amount of accommodation that can be relaxed. |
true
|
|
|
What does a high PRA indicate?
|
-possibly suppressing the eye
-esophoria at near |
|
|
In presbyopes, what is the expected PRA? +/-
|
+
|
|
|
True or false
The amount of minus sphere added in PRA, indicates the amount of accommodation that can be stimulated. |
true
|
|
|
In NRA, if it is >2.5, is the patient underminused/overminused?
|
overminused
|
|
|
A plus power above the patients control Rx in FCC indicates?
|
lag of accommodation
|
|
|
If net is less than the control Rx in FCC, this indicates?
|
lead of accommodation
|
|
|
FCC can help to determine what in presbyopes?
|
tentative add
|
|
|
For the non-presbyope the FCC may ID?
|
-latent hyperopia
-a patient who could benefit from a plus Rx |
|
|
In regular astigmatism, the meridians are how far apart?
|
90˚ apart
|
|
|
In irregular astigmatism, the principle meridians are how far apart?
|
Not 90˚ apart
|
|
|
Irregular astigmatism usually results from a secondary cause such as?
a. keratoconus b. lens subluxation c. pterygium d. lens/zonule coloboma e. all of the above |
e. all of the above
|
