It extends from the etiology to the management measures. A little effort to make people understand LOW VISION. Vivek Chaudhary, Christian College BSc Optometry, Bangalore. Frm NEPAL, LAHAN

1. LOW VISION:COMPREHENSIVE
BY VIVEK
CHAUDHARY
8TH DEC 2016

2.  .
 Low vision can be described as reduced vision which cannot be
corrected by optical or surgical means
 WHO, “ A person with low vision is one who has impairment
and/or standard refractive correction and has a visual acuity of less
than 6/18 to light perception in the better eye or a visual field of
less than 10 degrees from the point of fixation, but who uses or is
potentially able to use, vision for planning and/or execution of a
task”

3. Conditions causing low vision
It includes :
 ARMD ( Age Related Macular Degeneration) – Central loss
 Diabetes- Retinopathy Laser treatment
 Acquired (traumatic) brain injury
 Nystagmus
 Congenital cataract
 Multiple sclerosis
 Glaucoma
 Albinism
 Retinitis pigmentosa

4. 1.ARMD
 Idiopathic. Age is the primary factor for ARMD
 Also caused by cigarette and nutritional imbalance.
 Most common cause of visual loss in Western countries
 Causes central vision loss
 Non-exudative ARMD causes slow progress of vision loss
 Exudative ARMD causes rapid progress of vision loss

6. Visual Acuity may vary with the extent of the degeneration :
• With dry stages ARMD, acuity can range from 6/6 to 6/120.
• With wet stage(exudative) ARMD, the acuity can show worse than
6/120
• Main problem is very difficulty to reading or writing.

7. Central vision loss
Amsler Grid

8. 2. Diabetic Retinopathy
 leading cause of blindness in the U.S for patients age 20 to 74.
 Vision loss due to two major problems : a. Macular edema b. proliferative DR
Effects on vision ;
• Fluctuating vision
• Loss f central sharp vision
• Profound loss of vision
• Color vision impairment
• Reduced side vision after LASER
• Night Blindness after LASER
• Glaucoma
• Cataracts

15. Traumatic Brain Injury (TBI)
 Loss of Visual Field : homonymous hemianopia mostly
 Visual spatial disorders and visual neglect
 Vertigo, dizziness and impaired eye movements
 Double vision
 Eye strain and difficulty in reading
 Light sensitivity , Dry eyes
 Visual hallucinations
 Impaired visual memory

19. Nystagmus
 Def : Involuntary, rhythmic shaking of the eyes (dancing eyes
or jerking eyes).
 Effects on vision
 Fluctuating vision
 Null position : unusual head and eye position
 Binocular vision impairment

20. Congenital Cataracts
 Cataract formation since birth
 Occurs due to birth defects like Down syndrome, congenital rubella, inherent
cataract and so on
 OR due to drug infection like Tetracycline which is given for pregnant women for
infection
 Very rare to occur

22. Multiple Sclerosis
 Def : demyelinating disease in which the insulating cover of nerve
cells in the brain and spinal cord are damaged.
 Visual symptoms include Optic neuritis, Nystagmus and Diplopia

24. Glaucoma
 2nd leading cause of blindness
 Portions of VF lost usually with no warning signs or symptoms prior to
Vn deterioration
 Decreased peripheral vision is the first sign.
 Damages the optic nerve at the back of the eye leading to blindness
 Visual effects include gradual blurred Vn, photophobia, seeing halos
around light and vision loss in end stage
 Problem with orientation and mobility

26. Albinism
 Def : defect in melanin pigment production
 Effects on eyes , skin and hair
 Is inherited in an X-lined fashion
 No RPE makes blood vessels visible of the choroid
 Visual symptoms include light blue eyes, photosensitivity, nystagmus and
strabismus
 VA ranges from 20/40 to 20/200

30. LOW VISION AIDS
WHY AND NEEDS OF LVA

31. Needs
 Those with worsening sight and the prognosis of eventual blondness are at
comparatively high risk of suicide.
 These people can be given low vision aids
 LVA enhances the residual vision
 Makes individual do regular life activities.
 Via devices which are Optical , Non optical , electro-optical devices
 Aim is to magnify the image to be visible to patient

32. Optical devices for distance
 Telescopes Handheld or spectacle mounted
 Keplerian Telescope
 Galiliean telescope

33. Optical devices for near
 Spectacle : bifocals
 Magnifiers : handheld , stand and illuminated or non illuminated
 Electronic devices :CCTV
 Others : clip on loupes
 Bioptic
 Microscpoic lenses
 High addition lenses

35. Non optical devices
 Typoscopes
 Writing guide (signature, text, cheque)
 Illuminations
 Clour or tint
 Glare control devices
 Contrast enhancing

37. Low vision assessment
 History
 Visual acuity and refraction
 others

38. History
 Ocular history : to know the cause of the LV and progress of the disease
 Systemic disease that may pose difficulty in using certain devices : arthritis or
tremors

39. Refraction and visual acuity
 Distance visual acuity : light house distance visual acuity test chart
 Near visual acuity : light house near visual acuity test chart
 Benefits of lighthouse test chart over Snellen
 GP of each optotype size from line to line
 Five letters on each line
 Test distance of 2 m can be used to cover VA of 20/400

41. Others
 Contrast sensitivity
 Visual filed analysis ;
 Peripheral field using Humphrey or octopus perimetry
 Central field using amsler grid
 glare : history and measuring VA with or without illumination in the chart
 Colour vision

42. Low vision & low vision rehabilitation
 A person with a significant reduction in visual acuity due to ocular
diseases that is not correctable by surgery, conventional eye
glasses or contact lenses has Low Vision.
 The process of helping a person with low vision achieve the
highest level of visual function, independence, and quality of life
possible is Low Vision Rehabilitation

43. Objectives
 To develop independent living skills of visually impaired people and help
them regain self confidence for reintegrating into the community
 Identification
 Assessment of LV
 Assessment of handicap
 Management of LV to make it useful vision
 Device and training
 Social and environmental adaptation

44. Smart management : Things to do
 Listen , listen and listen
 Detail explanation about LV rehab programme
 Psychological management
 Friendly advice and counselling
 Follow up

45. THANK YOU !