1. Development of Visual Function

Question 1

What are the normal axial length of a neonatal male eye and an adult male eye?

Answer 1

Neonatal male eye = 16.78mm
Adult male eye = 23.15mm

Question 2

Describe the growth of an infant’s eye from birth to adulthood.

Answer 2

An infant eye grows rapidly in the first 2 years of life, then slows dramatically after 3 years of life. Growth in axial length continues until 13 years old.

Question 3

What are the average corneal diameter of a child and an adult?

Answer 3

Corneal Diameter
* Child = 9-12.5mm
* Adult = 10.50-12.75mm

Question 4

What are the average corneal thickness of a child and an adult?

Answer 4

Corneal Thickness
* Child (7-11 years) = 452-685 microns
* Adult = 512-570 microns

Question 5

What is the average refractive error at 3mo found in the Ocular Component Development during Infanct and Early Childhood (1995) study?

Answer 5

2.18 ± 1.30 D

Question 6

What is the average keratometer power at 3 mo found in the Ocular Component Development during Infanct and Early Childhood (1995) study?

Answer 6

43.9 ± 1.40 D

Question 6

What is the average axial length at 3 mo found in the Ocular Component Development during Infanct and Early Childhood (1995) study?

Answer 6

18.99 ± 0.54 mm

Question 7

In the Demonstration of anatomical development of the human macula within the first 5 years of life using handheld OCT study, what is the average adult foveal thickness found?

Answer 7

205 microns

Question 8

In the Demonstration of anatomical development of the human macula within the first 5 years of life using handheld OCT study, what are the foveal thickenss found at infancy, 1-2 years and 2-5 years?

Answer 8

• Infancy = 163 microns
• 1-2 years = 174 microns
• 2-5 years = 190 microns

Question 9

What does the development of human visual function depend upon?

Answer 9

Depends on multiple regions in the brain, very little to do with the eyes

Question 10

What are the 3 aspects that can be used to measure development of visual function?

Answer 10

• Visual Acuity
• Refractive Error
• Oculo-motor Control

Question 11

How is visual acuity measured in children in Catford & Oliver’s study (1973)? Why is it difficult to measure?

Answer 11

VA was measured using the OKN drum.
Visual attention is needed in order to collect reliable responses, therefore it is hard to obtain in children.

Question 12

How is visual acuity measured in Teller’s study: The vision of infants? What are the findings?

Answer 12

VA was measured using Forced Preferential viewing.
VA is found to be developed by 3 years of age (around 30 cycles per degree = 6/6)

Question 13

At what age is 6/6 VA expected according to Croucher, Brann and Rebeyre?

Answer 13

6 years of age