Epidemiology of Low vision

Question 1

what is visual impairment?

Answer 1

Reduced binocular visual acuity which cannot be improved with the best optical correction provided by conventional lenses (up to +4D for near vision add)

Question 2

why is it important to define visual impairment?

Answer 2

1.Social/ Financial benefits
2.epidemiological studies

Question 3

What are some other words for visual imparment?

Answer 3

1. Blind
2. Low vision
3. Subnormal vision
4. Visual impairment
5. Partial sight

Question 4

What are the two definitions of Visual impairment in the UK?

Answer 4

1. Severely sight Impaired / Blind
2. Sight impaired / partially sighted

Question 5

What is severely sight impaired / blind?

Answer 5

Blinds person act 1920 and National Assistance Act 1948

Blind as unable to perform any work for which eyesight is essential

(there is no reference to near vision, occupation or any particular occupation or disability)

Question 6

What are the clinical guidelines for Severely sight impaired / Blind?

Answer 6

1.Acuity below 3/60
2. Above 3/60 but below 6/60 with significantly contracted field
3. Acuity better then 6/60 but with substantially contracted fields especially inferior
4. Note blind category was changed to severely sight impaired 2003

Question 7

What are the impaired partial sight clinical guidelines?

Answer 7

There is no legal definition.
Substantially and permanently handicapped by defective vision caused by congenital defect, illness or injury.

NOTE: Partial sight category was changed to sight impaired in 2003

Question 8

How can we tell if the px has partial sight impairment?

Answer 8

1. 3/60 to 6/60 with a full field
2. Up to 6/24 with moderate restriction of the field, opacities or aphakia
3. 6/18 or better with a gross field defect

Question 9

What changes occurred in 2003?

Answer 9

1. Early identification of sight loss for social care
2. Improved access to social care
3. Increase registration
4. Improve accuracy of data collection

Question 10

what is the 20/20/20 rule?

Answer 10

Look 20ft away every 20 seconda dn +blink times

Question 11

What happened from November 2003 onwards?

Answer 11

Low vision leaflet LVL : Available from PC practices for px to self refer to social services
RVI : for eye clinic to refer px to social services. Should be done as soon as social needs become apparent, but where certification is not currently appropriate ; not seen by a consultant