Assessment and Diagnostic Evaluation of the Eye and Vision HISTORY Demographic (Basic profile) • Name • Age • Education • Occupation • Marital status • Date of admission Ocular History • The nurse, through careful questioning, elicits the necessary • Information that can assist in diagnosis of an ophthalmic condition. • Genetics plays a role in many eye and vision problems; for more information. Refractive Errors and Refractive Surgeries What Is a Refractive Error? Refractive error means that the shape of your eye does not bend light correctly, resulting in a blurred image. The main types of refractive errors are myopia (nearsightedness), hyperopia (farsightedness), presbyopia (loss of near vison with age), and astigmatism. Symptoms • • • Blurred vision. Difficulty reading or seeing up close. Crossing of the eyes in children (esotropia) Risk Factors People with high degrees of myopia have a higher risk of retinal detachment which may require surgical repair. Causes • Myopia (close objects are clear, and distant objects are blurry) Also known as nearsightedness, myopia is usually inherited and often discovered in childhood. Myopia often progresses throughout the teenage years when the body is growing rapidly. • Hyperopia (close objects are more blurry than distant objects) Also known as farsightedness, hyperopia can also be inherited. Children often have hyperopia, which may lessen in adulthood. In mild hyperopia, distance vision is clear while near vision is blurry. In more advanced hyperopia, vision can be blurred at all distances. • Presbyopia (aging of the lens in the eye) After age 40, the lens of the eye becomes more rigid and does not flex as easily. As a result, the eye loses its focusing ability and it becomes more difficult to read at close range. This normal aging process of the lens can also be combined with myopia, hyperopia or astigmatism. • Astigmatism usually occurs when the front surface of the eye, the cornea, has an asymmetric curvature. Normally the cornea is smooth and equally curved in all directions, and light entering the cornea is focused equally on all planes, or in all directions. In astigmatism, the front surface of the cornea is curved more in one direction than in another. This abnormality may result in vision that is much like looking into a distorted, wavy mirror. Usually, astigmatism causes blurred vision at all distances. Tests and Diagnosis A refractive error can be diagnosed by an eye care professional during a routine eye examination. Testing usually consists of asking the patient to read a vision chart while testing an assortment of lenses to maximize a patient’s vision. Special imaging or other testing is rarely necessary. Treatment Refractive disorders are commonly treated using corrective lenses, such as eyeglasses or contact lenses. Refractive surgery (such as LASIK) can also be used to correct some refractive disorders. Presbyopia, in the absence of any other refractive error, can sometimes be treated with over-the-counter reading glasses. There is no way to slow down or reverse presbyopia. Types of Surgery Types of surgery to correct refractive errors include: • LASIK (laser in-situ keratomileusis) • Photorefractive keratectomy (PRK) • Radial keratotomy (RK) LASIK This is surgery to correct myopia, hyperopia, or astigmatism. The procedure reshapes the cornea with an excimer laser. LASIK has replaced many of the other refractive eye surgery methods. This surgery is done using a computer-controlled excimer cold laser. It also uses a small blade called a microkeratome or a femtosecond laser. With 1 of these tools, the surgeon cuts a flap in the center of the cornea. A thin layer of tissue is removed using the excimer laser. This flattens the cornea. The flap is replaced without stitches. It reattaches to the cornea in minutes. • Dry eyes during healing • Eye discomfort in the first 24 hours after surgery Possible complications include: • Overcorrected or under-corrected vision • Irregular astigmatism • Corneal haze or glare • Sensitivity to light • Inability to wear contact lenses. • Loss of the corneal flap and need for a corneal graft. • Scarring • Infection • Blurry vision or vision loss Photorefractive keratectomy (PRK) This surgery is done with the same kind of excimer laser used for LASIK. PRK is done to reshape the cornea to correct mild to moderate nearsightedness (myopia). The excimer laser beam reshapes the cornea by removing tiny amounts of tissue from the outer surface. The procedure uses a computer to map the eye’s surface. It also calculates how much tissue to remove. This surgery generally takes a few minutes. Because the cornea surface is removed, it takes a few weeks to heal. The most common side effects include: • Eye pain that may last for several weeks. • Mild corneal haze right after surgery • Glare or halos around lights for months after surgery • • Don’t wear your contact lenses before surgery, as advised by your surgeon. This is to prevent your contact lenses from affecting the shape of the cornea. Don’t wear eye makeup for 2 days before surgery. Glaucoma Glaucoma is a disease that damages your eye’s optic nerve. It usually happens when fluid builds up in the front part of your eye. That extra fluid increases the pressure in your eye, damaging the optic nerve. What Is the Main Cause of Glaucoma? Radial keratotomy (RK) This procedure is used to correct mild myopia. Tiny cuts (incisions) called are made in the cornea with a diamond scalpel. The cuts flatten the center of the cornea and change its curve. This reduces refraction. Because the cornea is cut, it takes a few weeks to heal. This surgery was very common. But it has been nearly replaced by LASIK. Possible complications include: • Changing vision during the first few months • Infection • Discomfort • A weakened cornea that can rupture • Trouble fitting contact lenses. • Glare around lights • Clouding of the lens (cataract) • Vision loss Getting ready for surgery Most refractive eye surgeries are done on an outpatient basis. This means you go home the same day and don’t stay overnight in a hospital. Most surgeries last less than 1 hour. Before surgery: • Arrange for someone to drop you off and pick you up after surgery. How Do You Get Glaucoma? There are two major types of glaucoma. Primary open-angle glaucoma This is the most common type of glaucoma. It happens gradually, where the eye does not drain fluid as well as it should (like a clogged drain). As a result, eye pressure builds and starts to damage the optic nerve. This type of glaucoma is painless and causes no vision changes at first. Angle-closure glaucoma (also called “closed-angle glaucoma” or “narrow-angle glaucoma”) This type happens when someone’s iris is very close to the drainage angle in their eye. The iris can end up blocking the drainage angle. What Happens If You Have Glaucoma? Open-angle glaucoma symptoms With open-angle glaucoma, there are no warning signs or obvious symptoms in the early stages. As the disease progresses, blind spots develop in your peripheral (side) vision. Angle-closure glaucoma symptoms People at risk for angle-closure glaucoma usually show no symptoms before an attack. Some early symptoms of an attack may include blurred vision, halos, mild headaches, or eye pain. severe pain in the eye or forehead redness of the eye decreased vision or blurred vision. seeing rainbows or halos headache nausea vomiting Who Is at Risk for Glaucoma? Some people have a higher-than-normal risk of getting glaucoma. This includes people who: • are over age 40. • have family members with glaucoma. • are of African, Hispanic, or Asian heritage • have high eye pressure. • are farsighted or nearsighted • have had an eye injury • use long-term steroid medications. • have corneas that are thin in the center • have thinning of the optic nerve. • have diabetes, migraines, high blood pressure, poor blood circulation or other health problems affecting the whole body Glaucoma Diagnosis During a glaucoma exam, your ophthalmologist will: • measure your eye pressure. • inspect your eye's drainage angle. • examine your optic nerve for damage. • test your peripheral (side) vision • take a picture or computer measurement of your optic nerve. • measure the thickness of your cornea. Can Glaucoma Be Stopped? Glaucoma damage is permanent—it cannot be reversed. But medicine and surgery help to stop further damage. To treat glaucoma, your ophthalmologist may use one or more of the following treatments. Medication Glaucoma medications can help you keep your vision, but they may also produce side effects. Some eye drops may cause: • a stinging or itching sensation • red eyes or red skin around the eyes • changes in your pulse and heartbeat • changes in your energy level • changes in breathing (especially if you have asthma or breathing problems) • dry mouth • blurred vision • eyelash growth • changes in your eye color, the skin around your eyes or eyelid appearance Laser surgery • Trabeculoplasty. This surgery is for people who have open-angle glaucoma and can be used instead of or in addition to medications. The eye surgeon uses a laser to make the drainage angle work better. That way fluid flows out properly, and eye pressure is reduced. • Iridotomy. This is for people who have angleclosure glaucoma. The ophthalmologist uses a laser to create a tiny hole in the iris. This hole helps fluid flow to the drainage angle. Cataracts A cataract is when your eye's natural lens becomes cloudy. Proteins in your lens break down and cause things to look blurry, hazy or less colorful. Vision Problems with Cataracts If you have a cataract, your lens has become cloudy, like the bottom lens in the illustration. It is like looking through a foggy or dusty car windshield. Things look blurry, hazy or less colorful with a cataract. Cataracts Symptoms • Having blurry vision • Seeing double or a ghosted image out of the eye with cataract • Being extra sensitive to light (especially with oncoming headlights at night) • Having trouble seeing well at night, or needing more light when you read • Seeing bright colors as faded or yellow instead If you notice any of these cataract symptoms, notify your ophthalmologist. Cataracts can cause distortion or ghost images. What Causes Cataracts? • having parents, brothers, sisters, or other family members who have cataracts. • having certain medical problems, such as diabetes • smoking • having had an eye injury, eye surgery, or radiation treatments on your upper body • having spent a lot of time in the sun, especially without sunglasses that protect your eyes from damaging ultraviolet (UV) rays • using certain medications such as corticosteroids, which may cause early formation of cataracts. You may be able to slow down your development of cataracts. Protecting your eyes from sunlight is the best way to do this. Wear sunglasses that screen out the sun’s ultraviolet (UV) light rays. You may also wear regular eyeglasses that have a clear, anti-UV coating. Talk with your eye doctor to learn more. Cataracts can make images appear dull or yellow. Blurry or dim vision is a symptom of cataracts. Cataract Diagnosis Slit-lamp exam Your ophthalmologist will examine your cornea, iris, lens and the other areas at the front of the eye. The special slit-lamp microscope makes it easier to spot abnormalities. Retinal exam When your eye is dilated, the pupils are wide open so the doctor can more clearly see the back of the eye. Using the slit lamp, an ophthalmoscope or both, the doctor looks for signs of cataract. Your ophthalmologist will also look for glaucoma, and examine the retina and optic nerve. Refraction and visual acuity test This test assesses the sharpness and clarity of your vision. Each eye is tested individually for the ability to see letters of varying sizes. Cataract Diagnosis Intervention • Have an eye exam every year if you're older than 65, or every two years if younger. • Protect your eyes from UV light by wearing sunglasses that block at least 99 percent UV and a hat. • If you smoke, quit. Smoking is a key risk factor for cataracts. • Use brighter lights for reading and other activities. A magnifying glass may be useful, too. • Limit driving at night once night vision, halos or glare become problems. • Take care of any other health problems, especially diabetes. • Get the right eyeglasses or contact lenses to correct your vision. • When it becomes difficult to complete your regular activities, consider cataract surgery. • Make an informed decision about cataract surgery. Have a discussion with your ophthalmologist about: • the surgery, • preparation for and recovery after surgery, • benefits and possible complications of cataract surgery, • cataract surgery costs, • other questions you have. How does cataract surgery work? During cataract surgery, your eye surgeon will remove your eye’s cloudy natural lens. Then he or she will replace it with an artificial lens. This new lens is called an intraocular lens (or IOL). The capsule is the part of your eye that holds the IOL in place. Your ophthalmologist can use a laser to open the cloudy capsule and restore clear vision. This is called a capsulotomy.
