LV - Low Vision Definition and Epidemiology - Week 1

Question 1

Give the general definition low vision. What other term is included in this definition?
Also give the qalitative definition for low vision.

Answer 1

General - implies some reduction of vision, but not total blindness. Includes those who are legally blind.
Qualitative - best corrected vision is not adequate for a person’s needs.

Question 2

What is the quantitative definition of low vision, including visual fields and VA?

Answer 2

VA less than 6/18 but better than or equal to 6/120 or;
Visual field loss less than 20 degrees in the better eye with the best possible correction.

Question 3

What is meant by legal blindness?

Answer 3

Level vision impairment that entitles a person to disability pension

Question 4

How does the WHO define legal blindness (quantitative)?

Answer 4

<6/120 or visual field <10 degrees in the better eye with best correction

Question 5

What is the definition of legal blindness in Australia, including VA and field of view (3).

Answer 5

Best corrected VA of less than 6/60 in both eyes
Constriction to within 10 degrees of fixation in the better eye, irrespective of best corrected VA
Or a combination of visual dfects resulting in the same degree of impairment as the two above

Question 6

What are the two kinds of pensions available to legally blind individuals? Are they means tested?

Answer 6

Age-blind pension - for those over 65
Disability support pension - for those aged 16-65
-neither are means tested

Question 7

Define prevalence and incidence.

Answer 7

Prevalence - total proportion of the population that have the condition
Incidence - proportion of the population that develops the condition each year

Question 8

Why are population census inaccurate?

Answer 8

People do not report their condition accurately, people in nursing homes and mental health institutions exlcuded

Question 9

What do blind registers depend on?

Answer 9

Those who measure and report visual impairment and those with visual impairment to attend practitioners

Question 10

Why are surveys inaccurate?

Answer 10

Relies on old data from small sub-section of the population

Question 11

Why are population-based estimates inaccurate?

Answer 11

They are just estimates and strength depends on assumptions made by the estimator and sample used

Question 12

List the two main causes of vision impairment in Australia.

Answer 12

Uncorrected refractive error
Cataract

Question 13

List 3 notable causes of vision impairment in Australia.

Answer 13

AMD
Diabetic retinopathy
Glaucoma

Question 14

What is the main cause of blindness in Indigenous Australians? What about non-Indigenous Australians?

Answer 14

Indigenous - Cataract
non-Indigenous - AMD

Question 15

What is the cataract surgery coverage rate like for Indigenous Australians vs non-Indigenous Australians? Does it differ by remotness in either group?
Does the above apply to refractive error treatment cover?

Answer 15

Much lower in Indigenous Australians vs non-Indigenous Australians
Neither differed by remoteness
Refractive error - similar but less disparity

Question 16

Are the causes of low vision similar across the world and amongst other developed countries?

Answer 16

No, different casues

Question 17

What common cause of low vision in australia causes almost half the blindness?

Answer 17

Age-related maculopathy

Question 18

Between men and women, which gender has a higher distribution of visual impairment?

Answer 18

In every region - women

Question 19

Define the following as they are used in models of visual performance:
Disorder
Impairment
Activity limitation
Participation restriction

Answer 19

Disorder - deviation from normal structure
Impairment - organ function
Activity limitation - performing a certain task (read/write/mobilise)
Participation restriction - manner or extent of involvement in life situations

Question 20

List two main barriers to low vision services.

Answer 20

Concurrent major health problems
Patients not feeling the need for low vision services