Transcript BASIC LOW VISION SERVICE

BASIC LOW VISION
SERVICE
• NEW OPPORTUNITY OF SERVICE UNDER
AVOIDABLE BLINDNESS INITIATIVE
• Presentation on Adaptable technology for
• “Low vision devices” by Rtn. Ramesh Sathe
• District - 3130
Human brain is equipped
with 5 SENSES
WE ARE VISUALLY ORIENTED
FROM BIRTH
• Verbal messages are,received quickly, more
clearly understood and retained longer if
they are supported by visual example.
• SO POWERFUL IS THE SENSE OF VISION, BUT
MILLIONS OF PEOPLE SUFFER FROM VISUAL
DISABILITIES AND UNABLE TO PERFORM
DAILY ACTIVITIES.
BLINDNESS -Three
major questions
• WHAT is the magnitude of
the problem?
• WHY prevent blindness?
• HOW we can prevent?
VISION 2020: RIGHT TO SIGHT
(17TH February 1999)
• In order to drastically reduce the global
burden of blindness WHO and broad
coalition of INGO and private organisations
launched global initiative
• “ RIGHT TO SIGHT VISION - 2020 ”
• The objective is to eliminate avoidable
blindness by 2020.
Main causes of blindness
first phase of vision 2020
• Cataract - Clouding of crystalline lens.
• Trachoma- is common in areas of the world
that are socio -economically deprived of
basic needs.
• Onchocerciasis (River blindness)
• Childhood blindness.
• REFRACTIVE ERRORS AND LOW VISION
INDIA
IN 2001 HAS
STATISTICALLLY
SPEAKING
40 MILLION
BLIND PEOPLE
ALL ARE NOT TOTALLY
BLIND...!
A FACT NOT VERY COMMONLY
REALISED
BECAUSE BETWEEN
TOTAL BLINDNESS AND NORMAL
VISION THERE EXISTS
LARGE GREY AREA OF
“ LOW VISION ” …...
WHO recognizes vast grey area
between normal vision and total
blindness This can be called as
“LOW VISION”
• Low vision care is an important and
specialized eye care service by optometrist
and general public is not familiar with this.
• Entirely new concept and even
ophthalmologists are also not aware about
profound benefits of LV service
• It is estimated that 28
million people are in need
of low vision care in India.
If Appropriate LV Device is Given
These people can carry out
essential activities required in day
to day life
A global estimate of LV care
• 148 million Visually Impaired ( Blind + LV )
• 8 million blind without perception of light
• 140 Partially sighted out of this 105 million in
need of cataract surgery and or routine
refraction.
• 35 million in need of Low vision Care.
What is “Low Vision Service?”
• When conventional eyeglasses can no longer
help and surgery or other treatment not
appropriate - Then it is time to consider
“LOW VISION DEVICES”
• There are many types of LV devices but easy
availability, affordable cost and training
facilities are not available in developing
countries
Challenging field
• I thought this is a new opportunity of
service to a lot of poor and needy
people if the LV devices could be made
available at……..
• AFFORDABLE AND REASONABLY
LOW PRICE
• …....A must in any highly populated poor
country.
The unit can zoom from two
inches to infinity, one unit for
near and distance vision. Cost
6,000 US$-Not affordable by
developing countries
Our Aim to manufacture
quality devices
Indigenously at low cost
for each application
Asia Pacific
Regional Workshop
• There is a great and urgent need to expand
access to low vision care.
• Identify and train appropriate personnel for
delivery of the services.
• Emphasis on Appropriate technology and
production of low cost “Low vision devices”
• Ramesh Sathe was one of the Participants in
this workshop
Our Contribution to Avoidable
blindness Initiative
• We designed a kit for Education
and rehabilitation of visually
impaired people
• Our field trials proved
successful as 80.5% people
benefited.
BLIND EDUCATION
• History records that India and China are the
pioneers in blind education.
• Present atmosphere about this is depressing
as number of visually impaired persons is
increasing and there are negligible facilities
available.
• Urgent need to develop “Low Vision
Service”.
Present Situation
• All organisations working for blind
concentrate their efforts on
Education and Employment
• Visual disability due to aging is
common, but assistive devices for
elderly are not easily available.
• Simple devices can improve quality
of life of Elderly persons
Vision 2020 Includes three
pronged strategy
• Strengthen primary eye care programmes to
eliminate preventable causes.
• Develop surgical and therapeutic support to
deal effectively with curable eye problems.
• ESTABLISHING OPTICAL AND LOW
VISION SERVICE.
Basic Low vision service
• Partially sighted person has some residual
vision and with LV devices can maintain
independent and productive way of life
• Many patients with Macular degeneration,
diabetic retinopathy, and some other
disabilities can be given useful vision for
some daily task by identifying proper visual
aid.
• …..This can change the quality of life
IDENTIFICATION
Visual acuity
Pinhole
Functional questions
VA improved
REFRACTION
VA not improved
OPHTHALMIC EXAMINATION
Spectacles
Not treatable
Treatable causes
ASSESSMENT FOR LOW
VISION CARE
OUR FIELD TRIALS
Total patients Examined
Fitted in LV Definition
Could read smallest print with device
Minimum improvement
No Improvement
Total patients benefited
% benefit of LV patient
235
113
091
013
09
91
80.5
MAGNIFICATION:
A SOLUTION
• Increase the size of the object- (Large print
books,) or use of optical magnifier
• Decrease the viewing distance.
• Closed Circuit TV System
• Telescopic Magnification.
Ideal Magnifier
 An ideal magnifier would have high
power, large area, light weight, high
working distance and crystal clear
distortionless Magnification
 But the magnifier incorporating all these
properties is impossible as per basic laws of
physics
 We have to give up an advantage in order to
gain another considering the application.
Properties Of Magnifier important
for Low Vision Application
• Field of View
• Magnification
• Working Distance
• Mechanical Configuration
Use of following Types of
Magnifiers
• Fresnel lenses
• Aspheric Lenses (mounted
in spectacle and stand)
• Prismatic spectacles
• Closed Circiut TV System
Use of Aspheric Lenses
• LV application requires high power lenses
120 D to 300 D
• Spherical surfaces are easiest and economical
but suffer from spherical aberation, this is
insignificant upto 12D, but rapidly reduces
field of view.
• Aspheric lens is the solution, production of
glass lenses expensive, Therefore we
developed plastic lenses.
Prismatic Lenses
• Patients of macular degeneration may
improve vision by looking to the side of the
target so that the image is moved off the
diseased central region of the eye
• A theoretical alternative is to move the
image onto an adjacent healthy area, using
Prismatic lenses mounted in spectacle.
• Potentially prismatic spectacles are much
more useful than conventional LVA,S
Use of CCTV System
• Optical magnification systems
are limited.
• The magnification of a CCTV
system is much more.
• Contrast reversal is possible
• Magnification adjustable over a
wide range
• Can be used for longer duration.
• Very useful in creating
confidence of the patient
Tool for Education
• Any book can be
converted into large
print by using this
magnifier
Access to Entertainment
• For elderly persons
Reading of news
paper becomes
comfortable
Watching TV
Reading kit for students
• A joint activity in cooperation with National
Association for the Blind
and Govt. of Federal
Republic of Germany
• Many students will be
benefited
HUMAN RESOURCE
• In all developing countries there is a
shortage of eye care professionals.
• Therefore help of NGO’s /volunteers for
eye screening in schools, senior citizen
clubs is essential.
• Creating awareness is another important
task. Rotary Clubs can do this easily.
SIGHT IS NEXT TO LIFE
• Protect it
• Save it
• Restore it
• Let us work together
THANK YOU