DEVELOPMENT OF THE AMETROPIAS

Question 1

Higher degrees of _____ in premature infants (especially with very low birth weights

Answer 1

myopia

Question 2

5 or 6 year old children with +1.50 D or more ______ will still be that at age 13 or 14

Answer 2

hyperopia

Question 3

Majority of 5 or 6 year olds with refractive error of +0.50 to +1.24 D will be _____(-0.49 to +0.99 D) at age 13 or 14

Answer 3

emmetropic

Question 4

Most children entering school with refractive errors of 0 to +0.49 D will be _____ at age 13 or 14

Answer 4

myopic

Question 5

Children who are myopic at age 5 or 6 will become _____ myopic

Answer 5

more

Question 6

Changes in Hyperopes Compared with Myopes 

Among school-aged children, greatest changes in refractive error occurred in

Answer 6

myopes

Question 7

Changes in Hyperopes Compared with Myopes 

Refractive change is _____ when a child crosses from hyperopia into myopia.

Answer 7

faster

Question 8

Four types of myopia

Answer 8

Congenital 
Youth-onset
Early adult-onset 
Late adult-onset

Question 9

Axial Elongation of _____ chamber is responsible for myopia progression

Answer 9

vitreous chamber

Question 10

Emmetropic children between age 6 and 14 years old show: 

Answer 10

Increase in axial length 

Decrease in crystalline lens thickness 

Decrease in crystalline lens power

Question 11

Myopic Young Adults:
Greater _____ depth 
_____ corneal power 
Greater posterior crystalline lens _____

Answer 11

Greater vitreous depth 
Greater corneal power 
Greater posterior crystalline lens radius

Question 12

School-aged and Young Adult Females

Answer 12

Shorter eyes 
Steeper corneas 
More powerful crystalline lenses

Question 13

The earlier in life the onset of myopia occurs, the ____ the amount of myopia developed by late teens to young adulthood

Answer 13

greater

Question 14

Higher rate of childhood myopia _______ is associated with earlier onset of myopia

Answer 14

PROGRESSION

Question 15

How does astigmatism effect the rate of myopia progression?

Answer 15

Children with ATR at 5 or 6 years of age developed myopia by 13 or 14 years of age vs. those without astigmatism or WTR (not found in other studies) 

Once myopic, ATR astigmats do not have greater rates of childhood myopia progression

Question 16

What are factors associated with higher rates of childhood myopia progression?

Answer 16

Earlier onset age and/or higher initial amount of myopia

Near-point esophoria 

Temporal crescents and other myopic fundus changes 
Higher intraocular pressure 

Greater amount of time spent reading and doing near work 

Less time spent on outdoor activities

Question 17

What are drops for myopia to slow down its progression?

Answer 17

Atropine and Pirenzepine

Question 18

What type of contact lens can control myopia?

Answer 18

Rigid contact lenses

Question 19

Bifocal spectacle lenses can help control myopia. How?

Answer 19

These lenses provide different refractive correction for distance and near.

Question 20

What is most effective in lowering myopia progression rates for children with esophoria at near?

Answer 20

Bifocal spectacle lenses

Want a near addition power to shift near phoria to ortho / low exo range.

Question 21

What is another type of lens used for myopia control?

Answer 21

Progressive-addition Spectacle Lenses (PALs)

Question 22

5 to 6 year olds with _____ more likely to become myopic than those with ______.

Answer 22

5 to 6 year olds with ATR more likely to become myopic than those with WTR

Question 23

General Trends (Late teens or early 20s to ~40 years old) 

Answer 23

Refractive error stabilizes

Some have: 
Onset of myopia 
Progression of myopia 
Small shift in the hyperopic direction

Question 24

What is adult stabilization?

Answer 24

Adult Stabilization: childhood myopia progression is followed by stabilization of refractive error in young adulthood

Question 25

What is adult continuation?

Answer 25

Adult Continuation: childhood myopia progression followed by a general slower progression of myopia in young adulthood

Question 26

What is adult acceleration?

Answer 26

Adult Acceleration: refractive change in the myopic direction accelerates in young adulthood

Question 27

Adults with increases in myopia tend to have _____ in corneal power

Answer 27

Adults with increases in myopia tend to have increases in corneal power.

Question 28

What is it when Refractive Power Decreases (from decrease in crystalline lens power and decrease in corneal power)?  

Answer 28

Hyperopia

Question 29

It is unlikely for entering college student with ≥ +1.00 D (_________) in either principal meridian will be myopic after 4 years of school

Answer 29

noncycloplegic refraction

Question 30

After Age 45:  Shift in ______ direction  Some myopes increase in myopia  Age-related Nuclear Cataracts shift towards myopia

Answer 30

hyperopic | Trend Toward Hyperopia

Question 31

After 40, there is a trend of what kind of astigmatism?

Answer 31

Trend Toward Against-the-Rule Astigmatism

Question 32

Axial Length greater in:

Answer 32

neonatal eyelid closure juvenile corneal opacification congenital cataracts

Question 33

What are some causes of high myopia?

Answer 33

1. lid hemangiomas 2. ptosis 3. neonatal eyelid closure 4. retrolental fibroplasia associated with retinopathy of prematurity, vitreous hemorrhage In infants and children

Question 34

Prevailing Theories of Myopia Development:

Answer 34

1. Mechanical forces on the sclera 2. Retinal Defocus 3. Retinal Biochemistry

Question 35

What are mechanical forces on the sclera?

Answer 35

Tension from Extraocular Muscles and Intraocular Pressure --> axial elongation Could possibly be a cause of myopia.

Question 36

What is retinal defocus?

Answer 36

Defocus itself alters axial length (not the mechanism of accommodation) Could possibly be a cause of myopia.

Question 37

What is retinal biochemistry?

Answer 37

Biochemical agents affect the function of retinal synapses. Some studies show that this stops myopia, others show that these molecules induce myopia

Question 38

What is a possible cause of astigmatism?

Answer 38

Eyelid tension steepens the vertical corneal meridian and causes WTR. 1. Corneal WTR astigmatism decreases when eyelids lifted from eye  2. Corneal WTR astigmatism increases when palpebral aperture (conjunctiva) is narrowed  3. Shift towards ATR in over 40 years of age is due to decreased lid tension