a86357bdfd6c89205e33f45c5bd37802.ppt
- Количество слайдов: 36
BASIC LOW VISION SERVICE ORTUNITY OF SERVICE UNDER AVOIDABLE BLINDNESS • 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 (17 TH 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 ” …. . .
• 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
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 èAn ideal magnifier would have high power, large area, light weight, high working distance and crystal clear distortionless Magnification èBut the magnifier incorporating all these properties is impossible as per basic laws of physics èWe 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 12 D, 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
a86357bdfd6c89205e33f45c5bd37802.ppt