Visual Impairment

Whatever you may look like, marry a man your own age - as your beauty fades, so will his eyesight.

You know you're getting old when the candles cost more than the cake!

The spiritual eyesight improves as the physical eyesight declines. - Plato

Visual Impairment in the elderly… .. . Geriatrics Grand Rounds 24 th March 2006 Dr.Seraphine Soosaimanickam Geriatrics Fellow Hackensack Medical Centre UMDNJ

OBJECTIVES
Know and understand:
The leading causes and pathophysiology of visual loss
Techniques for preventing and treating visual loss
The signs of and treatments for common eye disorders in older persons
Techniques for low-vision rehabilitation

TOPICS
Causes of visual loss
Cataract
Age-related macular degeneration
Diabetic retinopathy
Glaucoma
Refractive error
Ischemic optic neuropathy
Keratitis sicca
Lid abnormalities
Herpes zoster ophthalmicus

VISUAL IMPAIRMENT
Visual impairment ( acuity < 20/40 )
Prevalence increases with age.
20% to 30% of those aged 75+ years
Blindness ( acuity < 20/200 )
Prevalence: 2% of those aged 75+ years
50% of blind population is aged 65 and older.
Visual impairment is associated with falls, car crashes, inability to perform ADLs,  quality of life.

CATARACT
Cataract is a clouding of the natural lens, the part of the eye responsible for focusing light and producing clear, sharp images.
The lens is contained in a capsule. As old cells die they become trapped within the capsule.
Over time, the cells accumulate causing the lens to cloud, making images look blurred. For most people, cataracts are a natural result of aging.

CATARACT
Prevalence: 20% of age group > 65 years; 50% of age group >75 years
Symptoms include increased glare, decreased contrast sensitivity,  visual acuity
Risk factors: decreased vitamin intake, light (ultraviolet B) exposure, smoking, alcohol use, long-term corticosteroid use, diabetes mellitus

Normal Vision

Vision with Cataract

CATARACT
Treatment: surgical extraction
90% of patients achieve vision 20/40 or better.
1.5 million surgeries are performed annually in US.
Local or topical anesthesia, sonographic breakdown and aspiration of the lens, placement of an artificial lens

SURGERY
Under an operating microscope, a small incision (3 mm) is made in the eye.
Tiny surgical instruments are used to break apart and remove the cloudy lens from the eye.
The back membrane of the lens (called the posterior capsule) is left in place.

Cataract surgery

CAPSULORHEXIS

Capsulorhexis
The surgeon creates an opening in the capsule, which is a micro-thin membrane surrounding the cataract. This procedure is called capsulorhexis.
It requires extraordinary precision since the capsule is only about four-thousandths of a millimeter thick! (thinner than a RBC)

Phacoemulsification
Phacoemulsification is the procedure in which ultrasonic vibrations are used to break the cataract into smaller fragments.
These fragments are then aspirated from the eye.

Phacoemulsification

Irrigation/aspiration
First the denser central nucleus of the cataract is removed.
Then the softer peripheral cortex of the cataract is removed using an irrigation/aspiration handpiece.
The posterior capsule is left intact to help support the intraocular lens (IOL) implant

Irrigation/aspiration

IOL IMPLANTATION
The intraocular lens is folded and passed through the tiny incision inside the “capsular bag”.
In the following illustration, the lens is being inserted via an “injector”. This instrument keeps the incision small while allowing implantation of a 6 mm lens through a 3 mm (or even smaller) incision

IOL IMPLANTATION

Intra Ocular Lens

Intraocular implant

Age-related macular degeneration
It is a degenerative condition of the macula (the central retina).
It is the most common cause of vision loss in the United States in those 50 or older
Prevalence increases with age

Pathophysiology
ARMD is caused by hardening of the arteries that nourish the retina.
This deprives the retinal tissue of oxygen and nutrients that it needs to function and thrive.
As a result, the central vision deteriorates.

AGE-RELATED MACULAR DEGENERATION
Risk factors: age, genetics, smoking, hypertension, fair skin
Diagnosis: presence (early) of drusen and (late) of choroidal neovascularization
Treatment is controversial
Vitamins, antioxidants, zinc
Prophylactic laser therapy
Photodynamic therapy

Vision with macular degeneration

Symptoms of Macular degeneration
The classic symptoms are
Decreased central visual acuity,
Metamorphopsia or image distortion,
and a central scotoma

Dry macular degeneration
The dry type is much more common
Typically results in a less severe, more gradual loss of vision.
Characterized by drusen and loss of pigment in the retina.
Drusen are small, yellowish deposits that form within the layers of the retina.

Non-Exudative macular degeneration

Drusen

Drusen
The drusen allow an angiogenic stimulant (such as vascular endothelial growth factor) to promote the growth of underlying choroidal blood vessels into the subretinal space and retina.
These tufts of neovascularization are fragile and have a propensity to leak and bleed, eventually forming a fibrovascular scar and resulting in irreversible vision loss

Exudative macular degeneration
Patient with wet macular degeneration develop new blood vessels under the retina.
This causes hemorrhage, swelling, and scar tissue but it can be treated with laser in some cases

Exudative macular degeneration

ARMD with subretinal hemorrhage Choroidal neovascularization and subretinal hemorrhage in a patient with late maculopathy.

Angiographic diagnosis
Hallmark of diagnosis of choroidal neovascularization has been the fluorescein angiogram .
It pinpoints the location and extent of neovascular membranes and can guide laser photocoagulation.
Unfortunately, only about 13% of angiograms show a treatable localized lesion, or "classic" choroidal neovascularization. The other 87% show diffuse,, hyperfluorescent lesions that are not amenable to laser photocoagulation

Iodocyanine green dye technique

Treatment
Currently there are no treatments or preventive measures, other than vision aids, for patients with dry macular degeneration.
The only clinically proven treatment for wet macular degeneration is laser photocoagulation

Laser treatment
Laser treatment guidelines vary, depending on the proximity of choroidal neovascularization to the fovea.
The common types of lesions are extrafoveal (200 to 2,500 micrometers from the fovea), juxtafoveal (1 to 199 micrometers from the fovea), and subfoveal (directly below the fovea).

Laser Photocoagulation
Laser photocoagulation is a destructive treatment in which tissue is ablated by heat.
This treatment quandary was investigated by the multicenter group
Their studies indicate that although patients treated with laser showed an immediate decrease in vision,
-20% of treated eyes had severe vision loss after 3 years,
-compared with 37% of untreated eyes.
However, the final visual acuities were very poor for both groups (20/320 for treated and 20/400 for control subjects

Photodynamic therapy
It is still experimental.
Photodynamic therapy, uses a photosensitive dye, which, when activated in the retinal vasculature by a light source, produces a thrombus that closes neovascular vessels.
Since the immunologic and coagulating systems naturally break down thrombi, this therapy may be a fast-acting temporizing measure, rather than a long-term treatment

Recommendations for ARMD
Use a halogen light. These have less glare and disperse the light better
Shine the light directly on your reading material. This improves the contrast and makes the print easier to see.
Use a hand-held magnifier.
Try large-print or audio books. Most libraries and bookstores have special sections reserved for these books.
Consult a low vision specialist. -specially trained to help visually impaired patients improve their quality of life.

DIABETIC RETINOPATHY
Among persons who have had type 2 diabetes for at least 10 years:
70% show retinopathy.
nearly 10% show proliferative disease.
Duration of disease and control of blood sugar are the most important variables.
Prevention: Tight glucose control and blood pressure control ( ≤ 130/80)
Treatment: Panretinal laser photocoagulation inhibits growth stimulus for neovascularization.

DIABETIC RETINOPATHY STAGES
Nonproliferative
Preproliferative
Proliferative

DIABETIC RETINOPATHY: NONPROLIFERATIVE STAGE
Microaneurysms
Intraretinal hemorrhages
Exudates
Macular edema

DIABETIC RETINOPATHY: NONPROLIFERATIVE STAGE Intraretinal edema and exudate in the superior macular region with type 2 diabetes.

DIABETIC RETINOPATHY: PREPROLIFERATIVE STAGE
Progressive ischemia
Hemorrhages
Venous caliber changes
Intraretinal microvascular abnormalities
Capillary nonperfusion

DIABETIC RETINOPATHY: PROLIFERATIVE STAGE
Neovascularization of the retina
Neovascularization of the disc
Neovascularization of both

DIABETIC RETINOPATHY: PROLIFERATIVE STAGE Neovascularization of the disc in a patient with proliferative retinopathy.

GLAUCOMA
Affects > 2.25 million Americans aged >40 years
Second most common cause of blindness worldwide. Most common cause of blindness among black Americans
$1 billion for glaucoma-related Medicare and Medicaid payments and disability
Defined as characteristic optic nerve head damage and visual field loss

Progressive optic nerve damage

Glaucoma
Progressive optic nerve damage (indicated by the cup to disc ratio) caused by glaucoma.
Notice the pale appearance of the nerve with the 0.9 cup as compared to the nerve with the 0.3 cup.
Grading is done by cup to disc ratio. (the depressed area in the center of the nerve) to the entire diameter of the optic nerve.

Vision with glaucoma

Vision with Glaucoma
The object you focus will appear clear -with an area to the side of your focus which will be blurry.
If you gaze at the blurry area it becomes crisp and now a different area on side will become blurry.
It is difficult to perceive early peripheral visual field defects .
Hence glaucoma is called the ‘ sneak thief of vision ’.

GLAUCOMA
Primary open-angle glaucoma is the most common type.
Slow aqueous drainage leads to chronically elevated intraocular pressures.
Patients are asymptomatic and may suffer substantial visual field loss before consulting a physician.
Causes are multifactorial and polygenic.

Glaucoma
Primary angle closure glaucoma (acute glaucoma) occurs much more rapidly when the flow of fluid inside the eye cannot pass through the pupil,
causing a rapid rise in pressure inside the eye.
Characterised by pain, redness and reduced vision.
The pupil of the eye is dilated.
The cornea is usually swollen, causing the haloes round lights and blurring of vision

Glaucoma Management :
Intraocular pressure-lowering medications (local and systemic, eg, latanoprost and brimonidine)
Argon laser trabeculoplasty
Intraocular surgery +/- antimetabolites
(5-fluorouracil, mitomycin-C)
Drainage devices
Ciliary body destructive procedures

REFRACTIVE ERROR
Leading cause of visual impairment
Treatment: eyeglasses, contact lenses, laser refractive surgery
Ametropia
Myopia (nearsightedness)
Hyperopia (farsightedness)
Astigmatism (visual distortion)
Presbyopia (  ability to focus at near objects)
Begins after age 40
Caused by gradual hardening of the lens and decreased muscular effectiveness of the ciliary body

Snellen chart

REFRACTIVE ERROR
Each line of the eye chart is assigned a notation in the form of a fraction that represents your visual acuity.
The numerator is the distance in feet the patient is from the eye chart.
The denominator represents the distance an eye with “normal” vision can read the same line.
Interpreting the numbers is simple. If you can read the 20/40 line, you’re able to see at 20 feet what a normal eye could see at 40.

ANTERIOR ISCHEMIC OPTIC NEUROPATHY
Microvascular occlusion of the blood supply to the optic nerve
Due to atherosclerotic vascular disease or inflammation (temporal arteritis)
Results in acute vision or field loss

ANTERIOR ISCHEMIC OPTIC NEUROPATHY Pallid swelling of the optic nerve head in a patient with anterior ischemic optic neuropathy.

KERATITIS SICCA
Tear production decreases with age
Characteristics: redness, foreign body sensation, and reflex tearing
Management: replacement of tears (artificial tears during daytime and ointment at bedtime)
Temporary or permanent punctal plugs may retard tear egress in severe cases.

LID ABNORMALITIES
Common among older adults
Gradual loss of elasticity and tensile strength that develops with age
Blepharochalasis (drooping of the brow) and blepharoptosis (drooping of the eyelid) may cause cosmetic deformity and, if severe, may impair vision.
Lid ectropion (eversion) or entropion (inversion) may cause discomfort.
Treatment: surgery

HERPES ZOSTER OPHTHALMICUS
Painful reactivation of varicella zoster virus
Affecting the ophthalmic division of the trigeminal nerve
Hutchinson’s sign: lesions on the tip of the nose
Oral acyclovir may shorten the course.
Post-herpetic neuralgia may be debilitating; treat with local ointments (capsaicin, lidocaine) or systemic medications (corticosteroids, tricyclic antidepressants).

Herpes zoster Ophthalmicus

LOW-VISION REHABILITATION
Available to patients with acuity < 20/60
Improved lighting and selection of reading material with bold, enlarged fonts and accentuated black-on-white contrast
Magnification: high-plus spectacles, magnifiers, closed-circuit television, telescopic devices
Eccentric viewing for macular degeneration patients with central macular pathology : training to use off-center fixation
Talking devices or Braille for those who have lost vision altogether

SCREENING TO PREVENT VISUAL LOSS
Comprehensive eye examinations are recommended every 1 to 2 years for persons aged 65 years and olde r.
(By the American Academy of Ophthalmology
and USPSTF)

SUMMARY
Visual loss occurs commonly among older adults
Leads to reduced quality of life, high medical care costs, and loss of independence
Primary care providers should routinely screen older adults for visual loss
Treatment options are available for many types of visual loss

THANK YOU!

http://dr-seraphine.blogspot.com	71
http://www.slideshare.net	8
http://aniwilfi.blogspot.com	3

Visual Impairment

by aniwilfi on Sep 29, 2009

Accessibility

Categories

Upload Details

Usage Rights

3 Embeds 82

Statistics

Visual Impairment Presentation Transcript