LV definitions

normal vision

20/40 or better

low vision

visual impairment that cannot be improved by meds, sx, corrective lenses and does not permit the pt from performing a specific task

low vision according to WHO

20/60 —> 20/400

or

VF 20deg or less

*in the better eye with the best possible correction

blindness according to WHO

VA less than 20/400 (3/60)

or

VF of <10deg (osea that’s how much they are seeing)

*in the better eye

near visual impairment

NVA worse than N6 or 0.8M @40cm

US classification

mild vision loss or near normal vision

20/40 -20/63

moderate VI and LV

20/70 - 20/160

severe VI, LV

20/200 - 20/400

profound VI, LV

20/500 - 20/1000

near total VI, LV

worse than 20/100

total VI, LV

NLP

vision impairment

functional limiation

no puede ver por algo

can result in visual disabiliity or visual handicap

i.e. VA and CS loss due to AMD

visual disability

limitation of abilities of pt

i.e in AMD: reading

(due to the VA & CS loss that was the impairment)

visual handicap

limitation of personal and socioeconomic independence

ie. in AMD unable to manage ATM due to difficulty reading (disability) from the reduced VA and CS less (impairment)

legally blind - american medical association (1934)

parameter used to certify that a person has a visual impairment

part 1: best VA 20/200 or less

no pueden leer ni UNA del 20/100

part 2: VF in better eye restricted to 20deg or less

therefore a 20/125+1 wouldn’t be blind bc they can read even ONE from 20/100

leading cause of vision impairment & blindness at global level

refractive errors & cataracts

what % of pts with RE have received access to proper intervention

36%

what % of pts with cataracts have received access to proper intervention

17%

estimated cost of productivity in the US

$411 billion

T/F vision loss can affect ages especially in pts over 50yo

True

cataract prevalence in US

mostly in non-hispanic whites

prevalence of VA loss or blindness in the US

increases significantly ~60s

prevalence of blindness in the US

~80s

F vs M prediliction

F>

but bc F get checked, thus dx more than men

prev of DR

peak ~55yo

what condition affects pts >40yo most

cataract (24,409,978 pts)

prev of AMD in the US

peak ~80s