Download 13 - Visual Optics Institute

1. In comparison to a normal Gaussian distribution, the distribution of spherical-equivalent
refractive errors for a young adult US population __________.
a. is leptokurtic in shape
b. has fewer high hyperopes (e.g., larger than +6D) than predicted on the basis of
chance.
c. has more high myopes (e.g., larger than -6D) than predicted on the basis of chance.
d. a and c are correct
e. a, b, and c are correct
2. In comparison the distribution of spherical-equivalent refractive errors for US children about to
enter first grade (i.e., 5-6 years of age), the distribution of refractive errors for a
population of normal full-term neonates _________.
a. is more leptokurtic in shape
b. peaks at a lower degree of hyperopia
c. is much broader and more closely resembles a normal Gaussian distribution.
d. has more large hyperopes (e.g., larger than -6D), but fewer large myopes (e.g., larger
than -6D)
e. none of the above are correct
3. In comparison to normal full-term infants, premature infants that are born before 32 weeks of
age and/or weigh less that 1500 gram __________.
a. exhibit shorter axial lengths and are more hyperopic
b. have steeper corneas and are more myopic
c. have flatter corneas and are more hyperopic
d. have steeper crystalline lenses and are more myopic
e. none of the above are correct
4. What is the expected the average spherical equivalent refractive error for a normal,
full-term, newborn infant?
a. +2.25 D
b. +1.5 D
c. +0.5 D
d. plano
e. -0.5 D
5. In a population of young adults, the distribution of ____________.
a. anterior chamber depths is leptokurtic.
b. corneal powers is leptokurtic.
c. corneal powers is flatter than a normal Gaussian distribution.
d. lens powers conforms to a normal Gaussian distribution.
e. axial lengths is flatter than a normal Gaussian distribution.
6. Which of the following ocular changes results in the largest changes in total refracting
power during the first 3 years of life?
a. a decrease in the refractive index gradient in the crystalline lens
b. an increase in anterior corneal radius of curvature.
c. a decrease in the posterior corneal radius of curvature
d. an increase in the anterior and posterior lens radii
e. none of the above are correct
7. Which of the following statements concerning the normal changes in astigmatism that
occur during life is NOT correct?
a. In a young Caucasian population, the prevalence of astigmatism decreases
between the ages of 6 months and 3 years.
b. The magnitude of astigmatism measured at 6 months of age is highly
correlated with the astigmatism measured at 6 years of age.
c. The total refractive astigmatism observed at 6 months of age is highly
correlated with the amount of corneal astigmatism.
d. In a young Caucasian population, the prevalence of astigmatism is higher at 6
months than at 30 years of age.
e. Most recent studies report that infants typically show with-the-rule astigmatism.
8. After 40 years of age, the eye develops more ______________.
a. against-the-rule/less with-the-rule astigmatism because the horizontal meridian
of the cornea gets steeper with age at a faster rate than the vertical meridian.
b. with-the-rule/less against-the-rule astigmatism because the vertical meridian of
the cornea flattens with age at a faster rate than the horizontal meridian.
c. against-the-rule/less with-the-rule astigmatism because the vertical meridian of
the cornea flattens with age at a faster rate than the horizontal meridian.
d. with-the-rule/less against-the-rule astigmatism because the horizontal meridian
of the cornea flattens with age at a faster rate than the vertical meridian.
e. none of the above are correct
9. Which of the following ocular components reaches adult-like dimensions at the
earliest age?
a. anterior chamber depth
b. vitreous chamber depth
c. horizontal corneal diameter
d. anterior crystalline lens radius
e. posterior crystalline lens raidus
10. In the US, the rate of myopic progression in juveniles is ___________.
a. about 0.25 D per year faster in females than in males
b. about 0.50 D per year
c. highly correlated with the rate of axial elongation
d. b and c are correct
e. all of the above are correct
11. Which of the following statements concerning the predictability of refractive errors in
young U.S. children is NOT correct?
a. If a 5-year-old is a +1.50 D hyperope, it is very unlikely that they will develop
juvenile onset myopia.
b. If a 5-year-old is a +0.75 D hyperope, it is very likely that they will remain
clinically emmetropic at least until early adulthood.
c. If a 5-year-old is a -0.50 D myope, it is very unlikely that they will be myopic in
their early teenage years.
d. If a 5-year-old is an emmetrope (plano Rx), it is very unlikely that they will
develop hyperopia of >+1.0 D in their early teenage years.
e. None of the above
12. With respect to the interocular balance of refractive errors during early infancy (0-3 yrs),
which of the following statements is correct?
a. Only 1 out of every 100 infants will exhibit a detectable anisometropia.
b. Infants who exhibit more than 1 D of anisometropia during early infancy almost always
development myopia later in life.
c. If an infant is isometropic (i.e., no anisometropia) at 1 yrs, there is only about a 1 out
of 100 chance that the infant will ever develop a significant anisometropia (e.g., >1.0
D).
d. The prevalence of significant anisometropia (e.g., >1,0 D) increases systematically
from birth to 3 years of age.
e. Anisometropias of about 1-2 D are frequently transient during early development and
not very predictive of the balance of refractive errors later in life.
13. For the average individual, which of the following ocular properties are most likely to show
systematic changes between 5 and 10 years of age?
a. axial length and corneal power
b. axial length and lens power
c. refractive error and axial length
d. vitreous chamber depth and corneal power
e. corneal power and lens power
14. Which of the following ocular changes is most responsible for the refractive changes in
individuals with early adult onset myopia?
a. a decrease in anterior chamber depth
b. a decrease in choroidal thickness
c. a decrease in corneal radius
d. an increase in vitreous chamber depth
e. an increase the refractive index of the lens core
15. Which of the following statements concerning the effects of moderate powered spectacle
lenses on emmetropization in young monkeys is NOT correct?
a. Infant monkey can alter the relative axial growth rates of the 2 eyes to compensate for
small degrees of optically imposed anisometropia.
b. It is not possible to produce hyperopic refractive errors with positive lenses in infant
monkeys.
c. Moderate powered negative lenses accelerate axial growth and promote the
development of myopia.
d. Infant monkeys typically recover from refractive errors produced by spectacle lenses if
unrestricted vision is restored early in life.
e. none of the above
16. Which of the following statements concerning the role of accommodation in emmetropization
and the development of refractive errors is correct?
a. Studies in monkeys have shown that prolonged accommodation during near work
produces axial myopia.
b. The fact that bifocals slow the progression of myopia demonstrates that
accommodation plays a key role in the genesis of myopia.
c. The fact that the bifocals are more effective in reducing myopic progression in
esophoic juveniles indicates that chronic over convergence promotes myopia.
d. Accommodation has an indirect effect on refractive development via its influence on
the eye’s retinal image quality.
e. C and D are correct.
17. Which of the following structures/pathways is essential for the development of formdeprivation myopia?
a. the fovea
b. the sympathetic input to the eye
c. visual cortex
d. accommodation
e. none of the above
18. Which of the following statements best describes refractive errors in twins?
a. Uniovular twins almost always have very similar refractive errors, however, the
degree of concordance between individual ocular components is no higher than it is in
dizygotic twins.
b. Uniovular twins may have very different refractive errors, but they will typically show a
high degree of concordance between at least 4 individual ocular components.
c. Even when raised in separate environments, uniovular twins almost always have very
similar refractive errors and show a high degree of concordance between individual
ocular components.
d. If biovular twins grow up in similar visual environments, they almost always have very
similar refractive errors and show a high degree of concordance between individual
ocular components.
e. For refractive errors between -6 D and +4D, the degree of concordance between
individual ocular components is approximately the same for monozygotic (uniovular)
and diyzgotic twins.
19. Which of the following factors is probably responsible for the decrease in hyperopia /
increase in myopia typically observed after about 65-70 years of age.
a. the onset of absolute presbyopia and the total loss of accommodation.
b. an effective forward shift of the crystalline lens.
c. a relative increase in the refractive index of the crystalline lens cortex in comparison
to the lens core.
d. a relative increase in the refractive index of the crystalline lens core in comparison to
the lens cortex.
e. an increase in vitreous chamber depth.
20. Which of the following statements concerning the implications of lens-rearing experiments in
laboratory animals on the phenomenon of emmetropization is NOT correct?
a. Emmetropization comes about primarily as a result of vision-dependent control over
axial growth.
b. The eye uses visual feedback associated with the eye’s effective refractive status to
guide ocular growth toward emmetropia.
c. Brief daily periods of either form deprivation or hyperopic defocus have a stronger
effect on eye growth in young animals than much longer periods of unrestricted or
clear vision
d. The emmetropization process has a limited operating range and refractive errors that
fall outside this range produce unpredictable growth.
e. None of the above
21. Which of the following statements concerning the effects of visual experience on
emmetropization is NOT correct?
a. Although LAISK procedures can correct the optical errors associated with myopia,
these surgical procedures do not reduce the extra risk for retinal detachment
associated with high degrees of myopia.
b. The potential for a clear retinal image is essential for normal emmetropization.
c. Viewing conditions that have been shown to produce axial myopic growth in young
animals first produce an increase in the thickness of the choroid.
d. Form deprivation myopia can be prevented by the topical application of the dopamine
agonist, apomorphine,
e. None of the above
22. Which of the following statements concerning treatment strategies for myopia is NOT
correct?
a. Recent studies have shown that progressive addition lenses actually accelerate
myopic progression in children who are orthophoric at near.
b. Topically applied anti-glaucoma drugs that reduce intraocular pressure do not prevent
or slow down the progression of myopia.
c. Topically applied atropine slows the progression of myopia even when it is
administered at night.
d. Pirenzepine is a relatively selective cholinergic muscarinic antagonist that has been
shown to slow the progression of juvenile onset myopia in a dose dependent fashion.
e. None of the above
23. With respect to the development of myopia, which of the following statements is NOT
correct?
a. For many individuals, myopic progression stops in late teenage years when axial
growth normally stops.
b. Between the ages of 30 and 40 years, late onset myopia is most likely due to an
effective increase in the power of the crystalline lens.
c. In general, the earlier the onset of myopia, the higher the final degree of myopia.
d. Children of two myopic parents are about 6 times more likely to become myopic than
children of non-myopic parents.
e. None of the above
24. Which of the following factors are thought to contribute to the normal shift toward hyperopia
(or less myopia) that occurs beginning at about 40-45 years of age?
a. a flattening of the crystalline lens, an increase in the refractive index of the crystalline
lens cortex, and possibly a decrease in vitreous chamber depth.
b. the onset of presbyopia, a flattening of the crystalline lens, an increase in the
refractive index of the crystalline lens cortex, and possibly a decrease in vitreous
chamber depth.
c. the onset of presbyopia, a flattening of the crystalline lens, a decrease in the refractive
index of the crystalline lens cortex, and possibly a decrease in vitreous chamber
depth.
d. the onset of presbyopia, a flattening of the crystalline lens, and possibly a decrease in
vitreous chamber depth.
e. None of the above
25. Which of the following statements concerning the mechanisms that mediate visiondependent eye growth are NOT correct?
a. FDM is an “all or none” process; the degree of axial myopia is independent of the
degree of image degradation.
b. The way in which the mechanisms that mediate vision-dependent eye growth
integrate the effects visual experience over time normally reduces the likelihood that
the eye will become myopic.
c. Because the mechanisms that mediate vision dependent growth integrate visual
experience over time in a non-linear way, the use of “diopters-hours” to quantify the
amount of near work is probably not the optimal measure.
c. The performance properties of the emmetropization process are qualitatively similar
across many species.
e. None of the above
26. Which of the following statements concerning the operational properties of the visiondependent mechanisms that regulate refractive development is correct?
a. Peripheral vision can influence foveal refractive development.
b. Early in life, a functioning fovea is essential for the recovery from vision-induced
refractive errors.
c. Visual signals from the fovea are essential for the phenomenon of form deprivation
myopia.
d. Peripheral image degradation will distort the shape of the eye without producing
myopia at the fovea.
e. None of the above.
27. Which of the following statements concerning the pattern of peripheral refractive errors
along the horizontal meridian is NOT correct?
a. The degree of radial astigmatism increases with eccentricity.
b. Myopic eyes (i.e., foveal refractive error) typically exhibit less myopia more hyperopia
in the periphery.
c. Hyperopic eyes (i.e., foveal refractive error) typically exhibit more hyperopia in the
periphery.
d. Clinical studies have suggested that in young emmetropic adults relative peripheral
hyperopia is a risk factor for adult onset myopia.
e. None of the above.
28. In the scleras of higher mammalian eyes, which of the following changes take place in
response to a myopiagenic stimulus like form deprivation?
a. There is a decrease in production of matrix metalloproteinases that act as gelatinolytic
enzymes
b. The rate of proteoglycan synthesis is reduced in the posterior pole.
c. The rate of synthesis of glycosaminoglycans (GAGs) increases near the equator of
the globe.
d. The creep rate for scleral tissue from the posterior pole decreases
e. two of the above are correct.
29. Which of the following statements concerning the anti-myopia effects of muscarinic
cholinergic blocking agents is correct?
a. Atropine can reduce the progression of juvenile onset only if the concentration is high
enough to produce at least partial cycloplegia.
b. Pirenzepine is much stronger than atropine and only has to be administered once a
week to prevent myopic progression in juveniles.
c. Although the duration of treatment required to slow myopic progression is not known,
it is likely that to maintain therapeutic effects, anti-myopia agents like atropine must
administered at least throughout the teenage years.
d. Pirenzepine reduces axial elongation rates by decreasing intraocular pressure.
e. None of the above.
30. Which of the following manipulations has been shown to reduce the progression of myopia
in animals or humans.
a. pharmacological blockade of action potentials in the optic nerve.
b. undercorrecting young myopes for distance by at least +0.50 D.
c. pharmacological stimulation of the sympathetic inputs to the eye’s anterior segment.
d. surgically removing the innervation to the lacrimal gland.
e. none of the above