Amblyopia, also known as “lazy eye,” is the lack of normal visual development in an eye, despite the eye being healthy. If left untreated, it can cause legal blindness in the affected eye. About 2% to 3% of the population is amblyopic.
Amblyopia signs and symptoms
Amblyopia generally starts at birth or during early childhood. Its symptoms often are noted by parents, caregivers or health-care professionals. If a child squints or completely closes one eye to see, he or she may have amblyopia. Other signs include overall poor visual acuity, eyestrain and headaches.
What causes amblyopia?
The most common cause of amblyopia is strabismus (intermittent or constant misalignment of the eyes). Another common cause is a significant difference in the refractive errors (nearsightedness, farsightedness and/or astigmatism) in the two eyes. It's important to correct amblyopia as early as possible, before the brain ignores vision in the affected eye.
Treatment of amblyopia
Amblyopic children can be treated with vision therapy (which often includes patching one eye), atropine eye drops, the correct prescription for nearsightedness or farsightedness or surgery.
Vision therapy exercises the eyes and helps both eyes work as a team. Vision therapy for someone with amblyopia forces the brain to use the amblyopic eye, thus restoring vision.
Sometimes the eye doctor or vision therapist will place a patch over the stronger eye to force the weaker eye to be used more. Patching may be required for several hours each day or even all day long, and may continue for weeks or months. If you have a lot of trouble with your child taking the patch off, you might consider a prosthetic contact lens that is specially designed to block vision in one eye but is colored to closely match the other eye.
In some children, atropine eye drops have been used to treat amblyopia instead of patching. One drop is placed in your child's good eye each day (your eye doctor will instruct you). Atropine blurs vision in the good eye, which forces your child to use the eye with amblyopia more, to strengthen it. One advantage of this method of treatment is that it doesn't require your constant vigilance to make sure your child wears an eye patch.
If your child has become amblyopic due to a strong uncorrected refractive error or a large difference between the refractive errors of their eyes, amblyopia can sometimes simply be treated by wearing eyeglasses or contact lenses full-time. In some cases, patching may be recommended along with the new glasses or contact lenses.
In cases when the amblyopia is caused by a large eye turn, strabismus surgery is usually required to straighten the eyes. The surgery corrects the muscle problem that causes strabismus so the eyes can focus together and see properly.
Amblyopia will not go away on its own, and untreated amblyopia can lead to permanent visual problems and poor depth perception. If your child has amblyopia and the stronger eye develops disease or is injured later in life, the result will be poor vision through the amblyopic eye. To prevent this and to give your child the best vision possible, amblyopia should be treated early on.
If amblyopia is detected and aggressively treated before the age of 8 or 9, in many cases the weak eye will be able to develop 20/20 vision.
Have you ever seen small specks or debris that looks like pieces of lint floating in your field of view? These are called “floaters,” and they are usually normal and harmless. They usually can be seen most easily when you look at a plain background, like a blank wall or blue sky.
Floaters are actually tiny clumps of gel or cells inside the vitreous – the clear, jelly-like fluid that fills the inside of your eye.
Floaters may look like specks, strands, webs or other shapes. Actually, what you are seeing are the shadows of floaters cast on the retina, the light-sensitive inner lining of the back of the eye.
Signs and symptoms of floaters and spots
With special exam lights, your eye doctor can detect floaters in your eyes even if you don’t notice them yourself.
If a spot or shadowy shape passes in front of your field of vision or to the side, you are seeing a floater. Because they are inside your eye and suspended within the gel-like vitreous, they move with your eyes when you try to see them.
What causes floaters and spots?
Some floaters are present since birth as part of the eye’s development, and others occur over time.
When people reach middle age, the gel-like vitreous begins to liquefy and contract. Some parts of the vitreous form clumps or strands inside the eye. The vitreous gel pulls away from the back wall of the eye, causing a posterior vitreous detachment (PVD). PVD is a common cause of floaters.
Floaters are also more common among people who:
- Are nearsighted.
- Have undergone cataract surgery.
- Have had laser surgery of the eye.
- Have had inflammation inside the eye.
Treatment for floaters and spots
Most spots and floaters in the eye are harmless and merely annoying. Many will fade over time and become less bothersome. People sometimes are interested in surgery to remove floaters, but doctors are willing to perform such surgery only in rare instances.
Flashes of Light
You may also see flashes of light. These flashes occur more often in older people, and usually are caused by mechanical stimulation of photoreceptors when the gel-like vitreous occasionally tugs on the light-sensitive retina. They may be a warning sign of a detached retina – a very serious problem that could lead to blindness if not treated quickly.
Some people experience flashes of light that appear as jagged lines or "heat waves" in both eyes, often lasting 10-20 minutes. These types of flashes are usually caused by a spasm of blood vessels in the brain, which is called a migraine. If a headache follows the flashes, it is called a migraine headache. However, jagged lines or "heat waves" can occur without a headache. In this case, the light flashes are called an ophthalmic migraine, or a migraine without a headache.
However, the sudden appearance of a significant number of floaters, especially if they are accompanied by flashes of light or other vision disturbances, could indicate a retinal detachment or other serious problem in the eye. If you suddenly see new floaters, visit your eye doctor immediately.
Retinitis pigmentosa (RP) is a rare, inherited eye disease in which the light-sensitive retina slowly and progressively degenerates. This causes progressive peripheral vision loss, night blindness, central vision loss and, in some cases, blindness.
RP affects approximately 1 out of every 4,000 Americans.
Signs and symptoms of retinitis pigmentosa
The first symptoms of retinitis pigmentosa usually occur in early childhood, when both eyes typically are affected. However, some cases of RP may not become apparent until affected individuals are in their 30s or older.
“Night blindness” is the primary symptom of the disease in its early stages. During later stages of retinitis pigmentosa, tunnel vision can develop, with only a small area of central vision remaining.
In one study of RP patients who were at least 45 years old, 52% had 20/40 or better central vision in at least one eye, 25% had 20/200 or worse vision and 0.5% had no light perception (total blindness).
What causes RP?
Not much is known about what causes retinitis pigmentosa, except that the disease is inherited. It is now believed that RP can be caused by molecular defects in 100 different genes, causing significant variations in the disease from person to person.
Even if your mother and father don't have retinitis pigmentosa, you can still have the eye disease when at least one parent carries an altered gene associated with the trait. In fact, about 1% of the population can be considered carriers of recessive genetic tendencies for retinitis pigmentosa that, in certain circumstances, can be passed on to a child who then develops the disease.
In RP, the light-sensitive cells in the retina gradually die. Usually, cells called rods are primarily affected. These cells are needed for night vision and peripheral vision. However, other cells called cones can also be affected. Cone cells are responsible for our central vision and color vision.
Retinitis Pigmentosa tests and treatment
Visual field testing likely will be done to determine the extent of peripheral vision loss. Other eye exams may be conducted to determine whether you have lost night vision or color vision.
No treatments currently are available for retinitis pigmentosa, although some practitioners believe that vitamin A supplements may delay vision loss.
Illuminated magnifiers and other low vision devices can be helpful to help RP patients get the most out of their remaining vision. Occupational therapy and psychological counseling are also recommended to help the person with RP deal with their vision loss.
Researchers are looking into ways to treat RP in the future, such as retinal implants and drug treatments.
Uveitis is inflammation of the eye's uvea, an area that consists of the iris, the ciliary body and the choroid. The iris is the colored part of the eye that surrounds the pupil. The ciliary body is located behind the iris and produces the fluid that fills the anterior part of the eye. The choroid is the layer of tiny blood vessels in the back of the eye that nourishes the light-sensitive retina.
Uveitis is classified by which part of the uvea it affects: Anterior uveitis refers to inflammation of the iris alone (called iritis) or the iris and ciliary body. Anterior uveitis is the most common form. Intermediate uveitis refers to inflammation of the ciliary body. Posterior uveitis is inflammation of the choroid. Diffuse uveitis is inflammation in all areas of the uvea.
Many cases of uveitis are chronic, and they can produce numerous possible complications that can result in vision loss, including cataracts, glaucoma and retinal detachment.
Uveitis signs and symptoms
Uveitis most commonly affects people in their 20s to their 50s. Signs and symptoms of uveitis include red eyes, pain, sensitivity to light, blurred vision and dark spots moving across your field of vision (floaters). These signs and symptoms may occur suddenly and worsen quickly.
If you experience any of these potential warning signs of uveitis, see your eye doctor immediately.
What causes uveitis?
The cause of uveitis is often unknown. However, in some cases, it has been associated with:
- Eye injuries.
- Inflammatory disorders, such as multiple sclerosis, Crohn’s disease or ulcerative colitis.
- Viral infections, such as herpes simplex or herpes zoster.
- Autoimmune disorders, such as rheumatoid arthritis or ankylosing spondylitis.
- Other infections, including toxoplasmosis and histoplasmosis.
To treat uveitis, your eye doctor may prescribe a steroid to reduce the inflammation in your eye. Whether the steroid is in eye drop, pill or injection form depends on the type of uveitis you have. Because anterior uveitis affects the front of the eye, it's easy to treat with eye drops. Intermediate uveitis can go either way, and posterior uveitis usually requires orally-administered medication or injections.
If an infection is suspected as the cause of your uveitis, your doctor may also prescribe additional medications to bring the infection under control. And if your uveitis has caused elevated intraocular pressure (IOP) in your eyes, drugs to reduce IOP to normal levels may also be used.
The duration of treatment for uveitis is often determined by the part of your eye that’s affected. With proper treatment, anterior uveitis can clear up in a matter of days to weeks. Posterior uveitis, on the other hand, may require a much longer period of treatment before it is completely under control.
Episodes of uveitis can recur. See your eye doctor immediately if signs and symptoms of uveitis reappear after successful treatment.
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