Common Eye Disorders
Macular Degeneration
What is macular degeneration?
The macula is a small area in the retina at the back of the eye that allows one to see fine details clearly and perform activities such as reading and driving. Macular degeneration is a deterioration of this very important area. In mild cases, vision may be only minimally impaired. Even in more advanced cases, people continue to have some useful vision and are often able to take care of themselves.
While there are different types of macular degeneration, the two most common are “dry” and “wet”:
- Dry macular degeneration is the more common form of the disease and results from a deterioration and breakdown of the macula. Vision loss is typically gradual, and symptoms may be minimal throughout the early stages.
- Wet macular degeneration is also known as exudative disease. This form accounts for about 10% of all cases and results when abnormal blood vessels begin to grow underneath the deteriorating macula. These new blood vessels have a tendency to leak fluid or blood. Vision loss may be rapid and severe.
What causes macular degeneration?
Many people develop some evidence of macular degeneration as they age, and the full name of this disease process is age-related macular degeneration (ARMD). Although the exact cause of this disease is yet to be determined, ARMD is the leading cause of severe vision loss in Caucasians over the age of 65.
What are the symptoms of macular degeneration?
Macular degeneration can cause different symptoms in different people. Most people with mild dry ARMD have very few, if any, symptoms. Sometimes only one eye loses vision while the other continues to see well for many years. When both eyes are affected, however, the loss of central vision is noticed more quickly. Patients may notice blurring of words on a page, dark or missing areas in central vision, and distortion of images. In severe cases, patients lose the ability to read, drive, and see faces. Despite these severe visual symptoms, ARMD alone does not cause complete blindness.
How is macular degeneration diagnosed?
Many people do not realize that they have a macular problem until late stages of the disease. Your eye care provider can detect early stages of ARMD during a medical examination that may include the following: vision testing, central field testing with an Amsler Grid, viewing the macula with an ophthalmoscope, and photography of the macula.
How is macular degeneration treated?
The treatment of ARMD depends on a number of factors including the type and duration of disease.
Dry ARMD is typically treated with nutritional supplements, including antioxidant vitamins and zinc. A large scientific study found that people at risk for developing advanced stages of ARMD lowered their risk by about 25% when treated with a high-dose combination of vitamin C, vitamin E, beta-carotene, and zinc.
In the past, the treatment of wet macular degeneration involved only laser surgery or photodynamic therapy. While these modalities are still used for select cases, most patients with new onset wet macular degeneration are now treated with injections designed to induce a regression of the abnormal blood vessels responsible for the disease. These new advances are offering exciting hope to patients with this challenging disease.
Despite all these treatments, however, many people with macular degeneration still experience some vision loss. Because side vision is usually not affected, a person’s remaining sight is very useful. Often, people can continue with many of their normal activities by using low-vision optical aids such as magnifying devices, closed-circuit television, and large-print reading materials.
Adapted from the American Academy of Ophthalmology
Cataract
What is a cataract?
A cataract is a clouding of the normally clear lens of the eye. Common symptoms of a cataract include blurred vision, glare or light sensitivity, poor night vision, double vision in one eye, or fading colors. While these are some common symptoms, only an eye care provider can determine whether these symptoms are due to a cataract or some other disease process.
There are several misconceptions about a cataract. A cataract is NOT:
- a film over the eye
- caused by overusing the eyes
- treated with laser surgery
What causes a cataract?
The most common type of cataract is related to the normal aging of the eye.
A number of other factors may cause a cataract to develop earlier:
- family history
- medical problems such as diabetes
- injury to the eye
- medications, especially steroids
- exposure to sunlight
- previous eye surgery
How is a cataract detected?
A complete examination by an eye care provider can detect the presence of a cataract, as well as other causes of blurred vision. If problems exist with other parts of the eye (e.g., the cornea, retina, optic nerve), these may be responsible for vision loss and may limit the amount of improvement in vision after cataract surgery. If improvement in vision is unlikely, an ophthalmologist (eye surgeon) may not recommend surgery despite the presence of a cataract.
How is a cataract treated?
Surgery is the only way a cataract can be removed. If symptoms, however, are not bothersome, surgery may not be needed. Sometimes a simple change in an eyeglass prescription may be helpful. There are no medications, dietary supplements, or exercises that have been shown to prevent or treat cataracts. Protection from excessive sunlight may help slow the progression of cataracts. Most sunglasses that screen out ultraviolet (UV) light rays or regular eyeglasses with a clear anti-UV coating offer this protection.
When should surgery be done?
Surgery should be considered when cataracts cause enough loss of vision to interfere with one’s daily activities. It is not true that cataracts need to be “ripe” before they can be removed, or that they need to be removed just because they are present. Cataract surgery can be performed when a patient’s visual needs require it.
Some common questions one may ask oneself include the following:
- Can I see well enough to do my job and drive safely?
- Can I see to read and watch television comfortably?
- Can I see well enough to do daily tasks such as cooking, shopping, yard work, and taking medications?
Based on symptoms and one’s visual needs, an ophthalmologist can help decide when surgery may be appropriate.
What can I expect from cataract surgery?
Over 1.4 million people have cataract surgery in the United States, and more than 95% of those surgeries are performed without complications. During cataract surgery, which is usually performed under local or topical anesthesia, the cloudy lens is removed from the eye. In most cases, the natural lens is replaced by a synthetic, permanent intraocular lens implant. This delicate surgery is performed using a microscope, fine instruments, and modern technology.
Cataract surgery is a highly successful procedure. Improved vision is the result in over 95% of cases unless there is a co-existing problem with the eye, such as macular degeneration, corneal disease, glaucoma, or many others. It is important to understand that these co-existing diseases may limit the improvement in vision after cataract surgery. It is also important to understand that complications can occur during or after the surgery, some severe enough to cause significant vision loss.
Adapted from the American Academy of Ophthalmology
Dry Eye
What is dry eye?
Normally, the eye constantly produces tears. By producing tears at a slow and steady rate, the eye stays moist and comfortable. Sometimes people do not produce enough tears or the appropriate quality of tears to keep their eyes healthy and comfortable. This condition is known as dry eye.
What are the symptoms of dry eye?
The usual symptoms include:
- stinging or burning
- a scratchy or sandy sensation
- excess mucus in or around eyes
- excessive eye irritation from smoke or wind
- excess tearing
- discomfort when wearing contact lenses
Excess tearing form dry eye may sound illogical, but it can be understood as the eye’s response to discomfort. If the tears responsible for maintaining lubrication do not keep the eye wet enough, the eye becomes irritated. Eye irritation prompts the gland that makes tears (lacrimal gland) to release a large volume of tears, overwhelming the tear drainage system. These excess tears can then overflow from the eye.
What is the tear film?
When one blinks, a film of tears spreads over the eye, making the surface of the eye smooth and clear. Without this tear film, good vision would not be possible.
The tear film normally consists of three layers:
- an oil layer
- a water layer
- a mucus layer
The oil layer, produced by the meibomian glands, forms the outermost surface of the tear film. Its main purpose is to smooth the tear surface and reduce evaporation of tears. The middle water layer makes up most of what we ordinarily think of as tears. This layer, produced by the lacrimal glands, cleanses the eye and washes away foreign particles and irritants. The inner layer consists of mucus produced by the conjunctiva. Mucus allows the water layer to spread evenly over the surface of the eye.
What causes dry eye?
Tear production normally decreases as we age. Although dry eye can occur in both men and women, women are most often affected, especially after menopause.
A wide variety of common medications can also cause dry eye by reducing tear secretion:
- diuretics for high blood pressure
- beta-blockers for heart disease or high blood pressure
- antihistamines for allergies
- sleeping pills
- pain relievers
How is dry eye diagnosed?
An eye care provider is usually able to diagnose dry eye by listening to a patient’s symptoms and examining the eyes. Sometimes special tests that measure tear production are necessary as well.
How is dry eye treated?
The primary way to treat dry eye is by “adding” tears. Eyedrops called artificial tears are similar to one’s own tears. They lubricate the eyes and help retain moisture. Artificial tears are available without a prescription. There are many brands on the market, and there are subtle differences between the brands. Preservative-free eye drops are recommended to people who are sensitive to preservatives or who have the need to take an eyedrop more than four times a day. Typically, one may use an artificial tear as often as necessary.
Another commonly used method to treat dry eye is by “conserving” tears. Tears drain out of the eye through small channels into the nose. Your eye care provider can temporarily or permanently close these channels with devices called punctual plugs. This closure conserves a person’s tears since it slows or inhibits them from entering the drainage system.
In addition to these methods, there is now a prescription medication (Restasis) that actually increases normal tear production, which may have been reduced by inflammation due to chronic dry eye. This medication must be prescribed by a physician and can be very effective in certain patients.
Adapted from the American Academy of Ophthalmology
Flashes and Floaters
What are floaters?
Floaters are actually parts of the vitreous inside the eye that have become more solid or opaque with time. The vitreous is the gel inside the eye that helps give the eye its shape. At birth, this gel is generally very clear. As we age, it dries out and shrinks and may become more solid in parts. Shadows of these areas on the back of the eye, or retina, are what cause the appearance of floaters, usually slowly over time. These are more easily seen when looking at a bright background, such as the sky or a white wall or page, because more light is reflected into the eye. Showers of new floaters are usually not normal and require swift medical attention, preferably by an eye doctor. These could possibly indicate a new retinal tear or detachment, a posterior vitreous detachment or inflammation. Though not all of these are vision threatening, it is difficult to determine which are and are not without a thorough investigation.
What are flashes?
Flashes in vision occur when there is some pulling or traction on the retina. They usually appear as bright lights or lightning bolts, particularly at the edges of one’s visual field. If these occur, especially with new floaters, it is important to see an eye doctor as soon as possible to be examined for a retinal detachment or tear. Flashes that occur in both eyes at once, usually with a jagged line and/or a swirly, sparkly pattern, are usually not caused by tugging on the retina. This type of visual phenomena usually lasts from 5 to 40 minutes and can move across one’s vision as time goes on. Sometimes they are associated with a migraine headache and sometimes not. These flashes are usually not serious, but if it is the first time you are experiencing them, or you are concerned, you should schedule a visit with your eye doctor.
Adapted from the American Academy of Ophthalmology
Diabetic Retinopathy
What is it?
Diabetes is a disease resulting from your body’s inability to control its blood sugar levels. It affects blood vessels throughout the body, particularly small ones in your kidneys, fingers and toes and eyes. The eye is the only place in the body where we can see blood vessels. Whatever is happening here is happening in other parts of your body as well, which is why yearly, dilated eye exams are important when you are diabetic.
When someone’s blood sugar is out of control for a long period of time, or there are severe changes over a short period of time, the blood vessels in the eye begin to leak blood and other fluids into the retina. Beginning stages of diabetic retinopathy usually do not affect one’s vision, but if left unchecked, it can cause blindness. In fact, diabetic retinopathy is one of the leading causes of blindness among American adults. If diabetic retinopathy is present, it is either monitored closely or treated with lasers, depending on the severity. In very severe cases, diabetic eye disease is treated by an intraocular surgical procedure called pars-plana vitrectomy. There are many symptoms of diabetic retinopathy including blurry vision and floaters, but only your eye care provider can tell you if you have diabetic retinopathy and require treatment.
Adapted from the American Academy of Ophthalmology
