Enhancing daily living for patients with low visionCORONA HOANG, OD

VIEWFINDER LOW VISION RESOURCE CENTER

1830 SOUTH ALMA SCHOOL RD. STE. 131, MESA,AZ 85210 480.924.8755

10001 WEST BELL RD. STE. 115, SUN CITY, AZ, 85351 623.583.1556

What is a visual impairment?

According to the American Optometric Association: Anyone with noncorrectable reduced vision is visually

impaired, and can have a wide range of problems.  Few people are totally without sight. Most individuals

today classified as "blind" actually have remaining sight and, thanks to developments in the field of low vision rehabilitation, can be helped to make good use of it, improving their quality of life.

Levels of visual impairment

World Health Organization has a classification system: When the vision in the better eye with best possible

glasses correction is: 20/30 to 20/60 Mild 20/70 to 20/160  Moderate 20/200 to 20/400 Severe 20/500 to 20/1,000  Profound

Levels of visual impairment cont.

less than 20/1,000 Near-total visual impairment, or near total blindness

No light perception Total impairment, or total blindness

There are also levels of visual impairment based on visual field loss (loss of peripheral vision). Visual acuity alone is not a good predictor

Someone with relatively good acuity (e.g., 20/40) can have difficulty functioning, while someone with worse acuity (e.g., 20/200) might not be having any real problems.

VA alone not a good predictor

Visual acuity 20/40 With visual field loss

Visual acuity 20/200 With no visual field loss

Visual Impairment

A person with a visual impairment may have “difficulty accomplishing visual tasks, even with prescribed corrective lenses, but who can enhance his or her ability to accomplish these tasks with the use of compensatory visual strategies, low vision and other devices, and environmental modifications" (Corn and Koenig, 1996).

Common causes of visual impairment or low vision

Age-Related Macular Degeneration Diabetic Retinopathy Glaucoma Cataracts Primary causes of low vision are eye diseases, but

may be inherited or caused by an eye injury or brain injury

Age-related Macular Degeneration

It is the most common cause of low vision in patients over the age of 60 years.

It is a progressive eye disease that effects the macula. The macula is part of the retina responsible for central vision.

There are two forms, wet and dry. Wet ARMD is less common, it can have a greater effect on

decreasing central vision. Dry ARMD is more common, approximately 85-90% of

patients have dry form. It has less vision loss than wet.

How does ARMD cause low vision

Retinal photo of ARMD There is a gradual breakdown of light-sensitive cells that convey information to the brain, and the supporting tissue underneath the macula.

This causes central vision loss

Central vision loss with ARMD

Normal ARMD visual impairment

Glaucoma

It is the second leading cause of blindness in the US. It is a group of eye diseases that effects the optic

nerve. The optic nerve sends information from the eye to the brain to form an image.

There are different types of glaucoma, the most common is Open Angle Glaucoma which accounts for 95%.

Open angle glaucoma is a slow painless progressive disease that can effect peripheral vision loss if left untreated.

How does Glaucoma cause low vision?

Retinal Photo of Glaucoma Elevate pressures in the eyes

can lead to glaucoma Without treatment there is a

gradual loss of side vision causing tunnel vision.

Patients will miss objects to the side and the corners of their eyes

Peripheral Vision loss due Glaucoma

Normal Glaucoma visual impairment

Cataracts

Cataracts is the leading cause of visual impairment for those over 55 years of age.

The lens is made of mostly water and protein. Protein is arranged in the lens to let light pass through.

As we age, the protein may clump causing a cataract. Cataracts is the clouding of the lens inside the eye that

effects vision. The most common cause of cataracts is age related.

However, it may also be caused by diabetes, eye injury, or medications.

How does Cataracts cause low vision?

When protein clumps in the lens it reduces the amount of light reaching retina causing blurry vision.

Symptoms may include double vision.

Diminished ability to see colors. Increase sensitivity to glare and

light. Poor night vision.

Cataracts

Normal Cataracts

Diabetic Retinopathy

It is one of the four leading causes of severe visual impairment in the US.

It is a result of Diabetes and effects the retina In some with diabetic retinopathy blood vessels may

swell and leak fluid. Others may have abnormal new blood vessel growth

on the surface of the retina.

How does Diabetic Retinopathy cause low vision?

Retinal photo If blood vessels leak in the macula,

vision will be blurry.

Fragile new blood vessels may grow into the eye, leak and block vision

May experience floaters

More difficulty at night

Hemorrhaging may cause retinal detachment.

Visual impairment due to DR

Normal Diabetic Retinopathy

Effects of visual impairment on daily living

Quality of life Emotional distress Read small print, such as labels on medicine bottles,

a telephone book, or food labels. Reading a newspaper or book. Recognizing people when they are close to you.

Effects of visual impairment on daily living continued

Seeing steps, stairs, or curbs. Reading traffic, street, or store signs. Doing fine handwork such as sewing, knitting,

crocheting, or carpentry. Writing checks or filling out forms. Playing games such as bingo, dominos, or card

games.

Effects of visual impairment on daily living continued

Taking part in sports such as bowling, handball, tennis, or golf.

Cooking. Watching television. Daytime driving. Night time driving.

Low vision rehabilitation for treatment of visual impairment

An Optometrist or Ophthalmologist whose practice focuses on low vision is skilled in the examination, treatment and management of patients with visual impairments.

Each type of low vision problem requires a different therapeutic approach.

Treatment plans may include prescription of glasses, specialized optical systems, therapeutic filters, non-optical options, and/or video magnification, and the prescription of rehabilitation therapy to effectively maximize visual functioning for activities of daily living. 

Information from AOA.org

Low vision aids and devices to enhance vision

Patients with a visual impairment can maximize their remaining vision through the use of low vision aids and devices.

The main principles behind low vision is to enhance contrast, control glare, and increase magnification.

Most people use multiple low vision aids because each is designed to serve a very specific purpose.

It is not unusual for someone to have five or more vision aids.

Source: Thevisioncouncil.org

Improving contrast and glare

Optical filters can improve vision for distance and near and decrease eye fatigue while protecting the eyes from UV rays

Magnification

Is essential for low vision devices to enhance daily living activities

Helps seeing objects, texts, or images better Many different types of devices and options for

specific tasks

Low vision devices for different tasks

Short term near Reading price tags, menus, medicine bottles, telephone

book, food labels

Long term nearHands free near work sewing,

crocheting, reading books, newspapers

IntermedieatePlaying cards, bingo

Low vision devices for different tasks continued

Distance spottingSeeing signs

Distance viewingWatching TV, driving, sports

events

Non optical Talking watches, large print

books, large font phone, computer programs

Some disadvantage of devices

Reading glasses may require extremely close working distance.

Smaller field of view on higher magnification devices , limiting the amount of words.

Good lighting needed for devices. If patient has a restricted field of view or large scotoma, it

may inhibit use of device. Some devices only allow for single magnification or power.

Video magnifiers for enhancing daily living

Capable of magnifying while maintaining good working distance and larger field of view.

Video magnifiers can enhance distance and close-up viewing.

They are electronic devices, and typically consist of a camera and viewing screen to aid people in tasks including reading, writing, grooming or even cooking.

Material placed under the camera is magnified and displayed on the video magnifier’s monitor.

Video magnifiers exist as desktop units, which use a closed circuit television for viewing, as well as portable or hand-held video magnifiers for use on the go or during short tasks.

High performance desktop video magnifier (CCTV). Featuring Sony HD, text-to-speech3-in-1 camera-far, intermediate, & near.

Experience the joy of reading with the push of a button.

28 viewing modes allows customization.

Slide mechanism provides flexibility for various camera arm positions.

(888) 811-3161

www.enhancedvision.com

High performance desktop video magnifier (CCTV).

Featuring Sony HD and text-to-speech.

Experience the joy of reading with the push of a button.

Screen easily pivots horizontally and vertically-providing the most comfortable viewing position.

28 viewing modes allows you to personalize. (888) 811-3161

www.enhancedvision.com

Desktop CCTV

Combines large magnification range with large field of view.

Enhances contrast.

Allows for smooth reading even at higher magnification levels.

Comes in 20’,22’, and 24’ monitors

Screen pivots

7 viewing modes(888) 811-3161

www.enhancedvision.com

Portable desktop CCTV. Sony HD camera.

Ideal for patients who travel for extended periods of time.

No longer have to purchase two desktop CCTVs.

Moving camera head allows patient to use device for multiple tasks, working with hands, seeing their own face; shave, make up, other people faces, distance.

28 modes. In 22’,24’, &27”

Remote control, line markers, obj. locator

Similar to Acrobat with few extras

Even more portable. <3lbs

Able to capture images. 28 custom modes.

Excellent option for students or people who attend presentations/conferences often. Camera rotates 330 degrees

Battery operated (up to 4 hours)

Built in LED lighting (888) 811-3161

www.enhancedvision.com

Crisp, high-definition imageLightweight and portable3.5x to 14x magnificationLarge 6.5” anti-glare LCD screen tilts for most comfortable viewing angleLarge field of view allow the reader to see more of the reading areaFreeze frame with adjustable size and contrast6 viewing modes to optimize contrast and brightness

New HD camera providing a crisp, clear colorful, high definition picture.It’s new ergonomic lightweight compact design makes it the perfect companion whether at home or on the go.Can be used for reading and many near spotting tasks

Reading menusShopping- seeing price tags and labelsSeeing household items like stove dials and thermostatsSigning documents such as checks and receipts

THANK YOU FOR JOINING US

Corona Hoang, OD

Viewfinderlowvision.com(888) 811-3161

www.enhancedvision.com