Common Eye Problems:
Diabetic Retinopathy
Diabetes is a disease which affects the blood vessels throughout the body, particularly vessels in the kidney and eye. When the blood vessels in the eye are affected, this is called diabetic retinopathy.
The retina lies in the back of the eye and is a multi-layered tissue which detects visual images and transmits these to the brain. There are major blood vessels which lie on the surface, or the front portion, of the retina. When these blood vessels are damaged due to diabetes, they may leak fluid or blood and grow scar tissue. This leakage affects the ability of the retina to detect and transmit images.
Diabetic Retinopathy is the leading cause of new blindness among adults in the United States. If untreated, there is a risk of becoming blind. The longer one has diabetes, the higher the incidence of developing diabetic retinopathy. Approximately 80% of people who have diabetes for 15 years have some damage to their retinal vessels. With today's treatment only a small percentage of people have serious vision problems.
There are two types of diabetic retinopathy. Nonproliferative retinopathy is considered the early stage. Reading vision is typically not affected, but it can advance and cause severe vision problems. There are usually no symptoms with diabetic retinopathy. An exam is the only way to diagnose changes in the vessels of your eyes.
When the retinopathy becomes advanced, new vessels grow, or proliferate, in the retina. These new vessels are the body's attempt to overcome and replace the vessels which have been damaged by diabetes. But these new vessels are not normal. They may bleed, which causes vision to become hazy and sometimes causing a total loss of vision. These new vessels can also damage the retina by forming scar tissue and by pulling the retina away from its proper location. This stage, called proliferative retinopathy, requires immediate medical attention. Treatment is necessary to prevent severe loss of vision. Regular eye exams are crucial for all persons with diabetes. The progressing damage to the blood vessels in the eye can be slowed with treatment.
Dry Eye Treatment
The eye has a tear film which coats the outer layer of the eye. This tear film is very important for the lubrication and comfort of the eye as well as for the clarity of vision. As we age, this protective tear film diminishes, and leaves the eye more exposed to the drying effects of the air, wind and dust. In many people the dryness is worse in the afternoon and evening.
Dry eye is not caused by a lack of tear production. In fact, during dry eye, the eye can still make so many tears that many patients complain of wet eyes and tearing with this malady. That's because the dryness causes the eye to produce more tears in an effort to replace the tear film. Dry eye is probably the most common problem seen in the eye doctor's office.
Dry eye symptoms include burning, stinging or a gritty sensation which may come and go depending on many factors. Itching, tearing and light sensitivity may also occur. Occasionally long strings of mucus can be stretched from a dry eye.
Blinking is very important for the maintenance of the tear film. When performing such activities as reading or working on a computer, we blink less frequently. This aggravates the symptoms of dry eyes. Sometimes environmental factors can also aggravate dry eye symptoms. Dry weather, either in hot or cold temperatures, robs the eye of needed lubricants. Cigarette smoke, fumes, dust and airborne particles are common irritants. In most patients, this condition is not associated with systemic disease.
Treatment helps in most patients. We cannot cure this condition, so treatment is an ongoing project. Usually artificial tears, available over-the-counter, soothe the eyes and give temporary relief. These artificial tears work for only an hour or two, at best, and must be repeated at frequent intervals. Ointments last longer, but they blur vision and are most effective at night.
Newer techniques to treat dry eye include plugs which block the tear duct. These plugs can be placed in the two tear ducts, top and bottom, in both eyes or in only the lower ducts. Some test plugs are also available which dissolve a few days after insertion. If the dry eye symptoms disappear when the temporary plugs are inserted, then permanent plugs should be considered as a treatment option.
Flashes & Floaters
The retina lies in the back of the eye and is a multi-layered tissue which detects visual images and transmits these to the brain. In front of the retina lies the vitreous humor. The vitreous is the jelly-like material that fills the large central cavity of the eye. It is composed primarily of water, but it is also made up of proteins and other substances which are more fibrous. The water and fibrous elements together give the vitreous the consistency of gelatin.
The vitreous is normally connected to the retina. During aging, the watery portion of the vitreous separates from the fibrous portions. As this occurs, the fibrous elements contract and can pull the vitreous away from the retina. This is called a Posterior Vitreous Detachment. This contraction on the retina is responsible for the characteristic "flashes" that often accompany the Posterior Vitreous Detachment. The "floaters" are frequently caused by the fibrous elements changing position during the Posterior Vitreous Detachment. They can also be caused by pieces of the retina being dislodged as the vitreous contracts. Besides aging, flashes and floaters are also associated with nearsightedness and injuries to the eye.
All patients who experience a recent onset of flashes and floaters should be examined immediately by their eye doctor. Most of the time nothing unusual is found, and simple reassurance is all that is needed. The flashes eventually go away, and the floaters diminish and become less bothersome with time.
However, in about 10% of the patients with a Posterior Vitreous Detachment, a tear of the retina is found. If left untreated, these tears may lead to a full retinal detachment. A full retinal detachment is a very serious sight threatening condition requiring a major surgical procedure to repair. When symptoms appear, it is important to examine the eye within a day of their onset. Changes can occur rapidly, and time can be of the essence if a retinal detachment is present.
Retinal tears are treated by sealing the tear with a laser or freezing technique (cryotherapy).
