CATARACTS A Leading Cause of Preventable Blindness Powerpoint Presentation

CATARACTS A Leading Cause of Preventable Blindness

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Slide 1 :

CATARACTS: A Leading Cause of Preventable Blindness Neda Karimi, M.D. University of Kansas Department of Ophthalmology August 4, 2004

Slide 2 :

Epidemiology Cataracts are the leading cause of blindness in the world More than 1.3 million cataract procedures are performed in the U.S. each year Visual disability associated with cataracts account for 8 million physician office visits each year

Slide 3 :

Cataract is the leading cause of blindness in those 40 years or older in the United States

Slide 4 :

History The earliest reference to cataracts can be found in Hindu writings from the 5th century BC The word Cataract comes from the Greek word meaning “Waterfall” Until the mid 1700’s, it was thought that cataract was formed by opaque material flowing, like a waterfall into the eye

Slide 5 :

Lens The human lens is a naturally clear structure located behind the iris and supported by the zonules The lens is avascular-It does not have a vascular supply

Slide 6 :

Structure The basic lens consists of a central nucleus surrounded by the cortex contained within the lens capsule

Slide 7 :

Optics When light passes through the pupil, it is focused by the lens to produce clear, sharp images on the retina, the light-sensitive membrane on the back of the eye that functions like the film of a camera

Slide 8 :

Optics When this arrangement is disturbed in any way, the transparency is lost This results in scattering of light, blurring, and blocking of the image

Slide 9 :

Structure The lens is made mostly of water and protein fibers The protein fibers are arranged in a precise manner that makes the lens clear and allows light to pass through without interference With aging, the composition of the lens undergoes changes and the structure of the protein fibers breaks down Some of the fibers begin to clump together, clouding areas of the lens, and leading to the loss of transparency

Slide 10 :

This loss of transparency, or opacity formation is called Cataract

Slide 11 :

Clouding of the lens is a normal part of aging About half of Americans older than 65 have some degree of clouding of the lens According to one study, after age 75, 39% of men, and 46% percent of women in the U.S. have visually significant cataracts

Slide 12 :

Cataracts produce a gradual, painless, progressive loss of vision, and many patients are unaware of vision problems Generally do not cause pain, or abnormal tearing But as the clouding progresses, the cataract eventually interferes with your vision

Slide 13 :

Commonly affect distance vision Cause problems with glare In the early stages, stronger lighting and eyeglasses can help deal with the vision problems If impaired vision jeopardizes your normal lifestyle, you might need surgery

Slide 14 :

Patients often describe trying to look through a fogged-up window Clouded vision can make it more difficult to drive a car, read, or see details

Slide 15 :

Symptoms Blurred vision Increasing difficulty with vision at night Glare, especially at night Halos around lights The need for brighter light for reading Double vision in a single eye Fading or yellowing of colors

Slide 16 :

Due to increase of yellow-brown pigment in the lens, color perception also is affected

Slide 17 :

These may also be symptoms of other eye conditions, therefore it is important to see your ophthalmologist annually, or if there is a persistent change in vision

Slide 18 :

Pain, redness, discharge, or irritation in the eye are usually not signs or symptoms of a cataract, but may be signs and symptoms of other eye disorders

Slide 19 :

Hypermature Cataract A cataract isn't dangerous to the eye unless the cataract becomes completely white, a condition known as an overripe (hypermature) cataract This can cause inflammation, eye pain and headache A hypermature cataract is extremely rare and needs removal

Slide 20 :

Types of Cataract The lens consists of three layers The outer layer is a thin, clear membrane It surrounds a soft, clear material (cortex) The hard center of the lens is the nucleus A cataract can form in any part of the lens

Slide 21 :

Nuclear Cataract Occurs in the center of the lens In its early stages, the patient may become more nearsighted or even experience a temporary improvement in reading vision This so-called “second sight” disappears as the lens gradually turns yellow and begins to cloud the vision Seeing in dim light and driving at night may be especially troublesome

Slide 22 :

Cortical Cataract Begins as whitish, wedge-shaped streaks on the outer edge of the lens cortex As it slowly progresses, the streaks extend to the center and interfere with light passing through the nucleus Both distance and near vision can be impaired Patients also have problems with glare and loss of contrast

Slide 23 :

Subcapsular Cataract Starts as a small, opaque area just under the capsule shell, usually at the back of the lens, right in the path of light on its way to the retina This type of cataract may occur in both eyes but tends to be more advanced in one eye than the other Often interferes with reading vision, reduces your vision in bright light and causes glare or halos around lights at night

Slide 24 :

Etiology Why age-related changes happen to the lens is not known One possibility is damage caused by unstable molecules known as free radicals Smoking and exposure to UV light are two sources of free radicals General wear and tear on the lens over the years also may cause the changes in protein fibers

Slide 25 :

Etiology Age-related changes in the lens are not the only cause of cataracts Some infants are born with cataracts or develop them during childhood Such cataracts may be the result of the mother having contracted rubella during pregnancy Metabolic disorders

Slide 26 :

Congenital Cataracts Responsible for nearly 10% of all visual loss in children worldwide Approximately 0.03% of newborns have some form of congenital cataract Most are not associated with additional developmental problems Around one fifth of these patients have a family history of congenital cataract but in up to half of all cases there is no family history

Slide 27 :

In the case of a newborn infant, a cataract causes the immature visual system to be deprived of the stimulation needed for normal development If left untreated, permanent visual loss may occur Unilateral cataracts are more likely to cause visual loss because of the competition between the two eyes

Slide 28 :

If the cataract is small there may be only slight blurring of vision with near normal visual development If the cataract is larger, or located more posteriorly, it can effect visual development In some cases this can lead to permanent amblyopia (lazy eye) Without adequate stimulation central vision can be permanently effected

Slide 29 :

Outcome is very much dependent on the type of cataract Some congenital cataracts impair visual development only to a small degree and may never require surgery If the cataract is only in one eye, there is a strong tendency for the child to prefer the healthy eye The eye affected by the cataract rarely achieves normal vision, therefore removal of the cataract is indicated

Slide 30 :

Etiology of Pediatric Cataracts Hereditary Autosomal dominant form most common Genetic and Metabolic Diseases Down syndrome Marfan’s syndrome Myotonic Dystrophy Maternal Infections Rubella, Syphilis, Toxoplasmosis, Varicella

Slide 31 :

Ocular Anomalies Aniridia-Absence of iris at birth Toxic Corticosteroids, Radiation Trauma

Slide 32 :

Risk Factors In Adults Exposure to sunlight (UV light) Smoking Diabetes Trauma (blunt or penetrating) Family history of cataracts Corticosteroid therapy Radiation exposure Electrical injury Myotonic dystrophy Uveitis- Ocular inflammation

Slide 33 :

Risk Factors Everyone is at risk of developing cataracts simply because age is the single greatest risk factor By age 65 about half of all Americans have developed some degree of lens clouding

Slide 34 :

Cataracts develop sooner in diabetic patients than in non-diabetic patients This is caused by shifts in the glucose, electrolyte, and water balance within the lens Fluctuating vision and rapid shift to near sightedness are symptoms of diabetes

Slide 35 :

Clinical Findings The most common objective finding associated with cataracts is decreased visual acuity This is measured with an office wall chart or near-vision card

Slide 36 :

Visual Acuity Acuity refers to the sharpness of vision or how clearly you see an object In this test, your eye doctor checks to see how well you read letters from across the room Eyes are tested one at a time, while the other eye is covered. Using the chart with progressively smaller letters from top to bottom, to determine the level of vision

Slide 37 :

Refraction This is performed by your doctor to see if the decrease in vision is simply due for need for new glasses, or if there is another process at work that accounts for the decrease in visual acuity

Slide 38 :

Slit Lamp Exam (SLE) SLE allows the ophthalmologist to see the structures of the eye under magnification The microscope is called a slit lamp because it uses an intense slit of light to illuminate your cornea, iris, and lens These structures are viewed in small sections to detect any small abnormalities

Slide 39 :

Dilated Exam Dilating drops are placed in the eyes to dilate the pupils wide and provide a better view to the back of the eyes It allows the ophthalmologist to examine the lens for signs of a cataract and, if needed, determine how dense the clouding is

Slide 40 :

Dilated Exam It also allows for examination of the retina and the optic nerve. Dilating drops usually keep your pupils open for a few hours before their effect gradually wears off

Slide 41 :

When pupils are dilated, patients will have difficulty focusing on close objects With your pupils open this wide, sunglasses are helpful on a sunny day, and you may need a driver to drive you home

Slide 42 :

Other Causes of painless Vision Loss Cataract Retinal detachment Macular degeneration Diabetes mellitus Glaucoma Retinal artery occlusion

Slide 43 :

Retinal detachment is often accompanied by floaters, flashes of light, and loss of peripheral vision, which is often described as a gray curtain or shade covering all or part of the visual field Risk factors include a history of previous ocular trauma, nearsightedness, retinal detachment in the fellow eye, or a family history of retinal detachment

Slide 44 :

Macular degeneration usually causes a slow, progressive loss of central vision Symptoms of acute vision loss and distortion result from leakage from abnormal subretinal vessels Patients should be referred to a retina specialist immediately

Slide 45 :

Diabetic retinopathy may also contribute to vision loss Findings include dot-and-blot hemorrhages, microaneurysms, dilated and tortuous vessels, and neovascularization of the disk and retina Cataracts often obscure the fundus, making assessment of diabetic retinopathy difficult

Slide 46 :

Open-angle glaucoma produces slow, painless visual field loss that usually begins peripherally Optic nerve damage and subsequent loss of peripheral vision occur at normal as well as elevated intraocular pressures With progressive optic nerve damage and visual field loss, central vision is the last to be affected

Slide 47 :

Cataracts are the most treatable cause of decreased vision in the United States For most patients, observation and frequent eyeglass prescription changes are sufficient When activities of daily living, such as driving, reading, working, and self-care are affected surgery should be discussed

Slide 48 :

Cataract Surgery should be considered when changes in eyeglasses no longer help, quality of life is jeopardized, and cataract removal is likely to have an impact on vision

Slide 49 :

Treatment Make sure that eyeglasses or contact lenses are the most accurate prescription possible Improve the lighting in your home with more or brighter lamps When outside during the day, wear sunglasses to reduce glare Limit night driving

Slide 50 :

Think about how the cataract affects your daily life Can you see to do your job and drive safely Do you have problems reading or watching television? Is it difficult to cook, shop, climb stairs or take medications? How active are you? Does lack of vision affect your level of independence? Are you afraid you'll trip or fall or bump into something?

Slide 51 :

Sometimes a cataract should be removed even if it doesn't cause major problems with vision If it is preventing the treatment of another eye problem, such as age-related macular degeneration, diabetic retinopathy or retinal detachment

Slide 52 :

If you have cataracts in both eyes and decide to have surgery, your eye doctor typically removes the cataract in one eye at a time This allows time for the first eye to heal before the second eye surgery

Slide 53 :

Cataract surgery is the most common operation performed on patients over 65 years of age More than 95% of patients have improved vision after surgery Benefits include improvement in uncorrected and best-corrected visual acuity, improved binocularity, depth perception, and increased peripheral vision to enhance patients' ability to drive, read, work, and manage their own medications

Slide 54 :

Advances in surgical technique and more sophisticated technology have helped make surgery a safe and effective treatment for cataracts Prior to surgery, your eye doctor measures the size and shape of your eye to determine the proper lens implant power This measurement is made with a painless ultrasound test

Slide 55 :

Cataract surgery is typically an outpatient procedure that takes less than an hour Most people are awake and need only local anesthesia On rare occasions some people may need general anesthesia if they have difficulty laying flat or have claustrophobia

Slide 56 :

Two things happen during cataract surgery — the clouded lens is removed, and a clear artificial lens is implanted

Slide 57 :

Phacoemulsification During phacoemulsification, phaco for short, the surgeon makes a small incision, where the cornea meets the conjunctiva

Slide 58 :

The surgeon then uses the probe, which vibrates with ultrasound waves, to break up (emulsify) the cataract and suction out the fragments

Slide 59 :

Once the cataract is removed, a clear artificial lens is implanted to replace the original clouded lens This lens implant is made of plastic, acrylic or silicone and becomes a permanent part of the eye

Slide 60 :

Some IOLs are rigid plastic and implanted through an incision that requires several stitches (sutures) to close However, many IOLs are flexible, allowing a smaller incision that requires no stitches

Slide 61 :

Patients usually go home the same day Patients are seen in the office the next day, the following week, and then again after a month so that he or she can check the healing progress It's normal to feel mild discomfort for a couple of days after surgery You may wear an eye patch or protective shield the day of surgery Your doctor may prescribe medications to prevent infection and control eye pressure

Slide 62 :

Post-op Course Patients are usually examined 1 day, 1 week and then one month after the surgery date

Slide 63 :

Complications of Surgery Vitreous Loss- 3.1% Vitreous Hemorrhage-0.3% Uveitis-1.8% Increased Eye Pressure- 1.2% Retinal Detachment- 0.7% Endophthalmitis- 0.13%

Slide 64 :

Post Operative Period Contact your doctor immediately if you experience any of the following signs or symptoms after cataract surgery: Vision loss Pain that persists despite the use of over-the-counter pain medications A definite increase in eye redness Light flashes or multiple spots (floaters) in front of the eye Nausea, vomiting or excessive coughing

Slide 65 :

Posterior Subcapsular Opacity This condition occurs when the back of the lens capsule eventually becomes cloudy and blurs vision PCO can develop months or years after cataract surgery Occurs approx. 20% percent of the time

Slide 66 :

Treatment for PCO is simple and quick Laser capsulotomy is a quick, painless outpatient procedure that usually takes less than five minutes Capsulotomy means "cutting into the capsule" and YAG is an abbreviation of yttrium-aluminum-garnet, the type of laser used for the procedure

Slide 67 :

YAG Laser Capsulotomy A technique in which a laser beam is used to make a small opening in the clouded capsule to let light pass through

Slide 68 :

Post YAG Afterward, patients typically stay in the doctor's office for about an hour to make sure the eye pressure is not elevated In some people, particularly those who have glaucoma or are extremely nearsighted, YAG laser surgery can raise eye pressure Other complications are rare but can include swelling of the macula and a detached retina

Slide 69 :

Most cataracts occur with age and can't be avoided altogether Regular eye exams remain the key to early detection You can take steps to help slow or prevent the development of cataracts

Slide 70 :

Do not smoke Smoking produces free radicals, increasing your risk of cataracts. Eat a balanced diet Include plenty of fruits and vegetables. Ultraviolet light protection since UV light may contribute to the development of cataracts Diabetes Control

Slide 71 :

New Frontiers Researchers are continuing to explore new ways to prevent and treat cataracts, such as developing medications that would reduce or eliminate the need for surgery Until then, cataract surgery is the method to restore vision

ashley on Apr 16, 2009 Says :

I was looking for the references and representative notes But there are none

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If it is preventing the treatment of another eye problem, such as age-related macular degeneration, more If it is preventing the treatment of another eye problem, such as age-related macular degeneration, diabetic retinopathy or retinal detachment … less