Presbyopia Flashcards
aging in the ciliary muscle leads to Loss of muscle fibers and a (increase/decrease) in connective tissue
increase
aging in ciliary muscle leads to Contractile force does not (decrease/increase), it (increases/decrease) and is at a maximum at the age presbyopia is manifest
decrease
increases
The inner apex of the unaccommodated ciliary muscle resides further (forward/backward) and (inward/outward) toward anteroposterior axis in teh aging eye
forward
inward
T/F at rest the aged human ciliary muscle may be less able to hold or pull the crystallin lens into its flattened and unaccommodated configuration
T
T/F Unaccommodated aged ciliary muscles has the same configuration as young accommodated ciliary muscle
T
Thickness of the lens capsule (increases/decreases) from ___µm at birth to __ µm at 60 years then (decreases/increases) slightly thereafter
A) 11-30
B)11-20
C)1-20
increases
11-20
decreases
Force transmitted per unit thickness (decreases/increases) by half at age 60
decreases
(Increased/decreased) thickness compensates for the loss of elasticity
increased
The (capsule/ciliary body/iris) also gets more brittle in aging, (more/less) extensible , and (thinner/thicker)
capsule
less
thicker
- -Thickness of the lens capsule increases from 11µm at birth to 20 µm at 60 years then decreases slightly thereafter
- -Force transmitted per unit thickness decreases by half at age 60
- -Increased thickness compensates for the loss of elasticity
- -The capsule also gets more brittle
- all of these describe what theory of aging in the lens capsule?
Fisher theory
Growth of the _(ciliarybody/iris/lens)___ is continuous throughout life
lens
Growth of the lens has a linear mass (increase/decrease) of ___times over the human life span
A) 3.5
B)2.5
C)1.5
increase
1.5
T/F The eqatorial diameter decreases throughout the growth of the lens
F. INCREASES
When removed from the eye and isolated from external zonular forces, younger lenses tend to become (accommodated/unaccommodated) while older presbyopic lenses (do not/do) undergo a change in shape.
accommodated
do not
Hardness of the lens undergoes more than a four-fold , exponential (decrease/increase) over the a life span and wont stop until the age of ___
A) 35
B)50
C)60
D)40
increase
50
T/F Hardness of the lens can account for loss of accommodation with increasing age
T
T/F although presbyopia results in a complete loss of accommodation by age 50 yrs, the hardness of the human lens continues to increase beyond this age throughout the human life span
T
As someone ages:
- -lens thickness (increases/decreases/same)
- -anterior chamber depth (increases/decreases/same)
- -anterior segment length (increases/decreases/same)
increases
decreases
stays the same
Lenticular sclerosis is describing when the crystalline lens gets harder with (increasing/decreasing) age
increasing
What happens to the lens when describing lenticular sclerosis
gets harder with increasing age
Lenticular sclerosis is most commonly articulated as the explanation for (hyperopia/myopia/persbyopia)
presbyopia
Presbyopia is a consequence of the altered geometry of the (lens/zonular/iris/cornea/maccular) relationship
–pick two
lens/zonular
In young lens–the anterior zonular connections are (far/near) the lens equator and exert strong influence on the curvature of the lens–from the geometric theory
near
Aged lens–the zonular connections are farther forwad so there is not effective (relaxation/contraction) of the force with ciliary muscle contraction –from geometric theory
relaxation
T/F the geometric theory argues that aged lenses have zonular connections that are farther forward so there is no effective relaxation of the forse with ciliary muscle contraction
T
T/F the geometric theory argues that in young lenses the anterior zonular connections are near the lens equator and exert strong influence on the curvature of the lens
T
The disaccommodation theory states that presbyopia (is/is not) caused by a failure of the lens to accommodate,But it (is/is not) caused by a gradual failure of the lens to be held in an (unaccommodated/accommodate) form at rest
is not
is
unaccommodated
The (multifactorial/unaccommodation/geometrical) theory presbyopia results not from an single causal factor, but through global deterioration of (accommodative/unaccommodative) function of many aspects of the (accommodative/unaccommodative) apparatus
multifactorial
accommodative
accommadative
T/F
Multifactorial theory states:
Presbyopia is not an end point, but a time point in a gradual, progressive continuum of deterioration of the accommodative structures
T
Spectacle lenses Contact lenses Corneal refractive surgical procedures Or artificial intraocular lenses (IOLs) --all of these can be used as optical compensation for (presbyopes/hyperopes)
presbyopes
presbyopia ultimately culminates in the (gain/loss) of physiologic funciton
loss
