Diseases

Cataract
A cataract is an opacity or cloudiness in the natural lens of the eye. It is still the leading cause of blindness worldwide and represents an important cause of visual impairment in the United States. The development of cataracts in the adult is related to aging, sunlight exposure, smoking, poor nutrition, eye trauma, systemic diseases, and certain medications such as steroids.
Just as a smudged or dirty camera lens may spoil a photograph, opacity in the natural lens of the eye can result in a blurred image. Patients with cataracts usually complain of blurred vision either at distance, near, or both. This may interfere with tasks such as driving or reading. Other common complaints include glare, halos, and dimness of color vision. When you are no longer able to see well enough to do the things you like to do, cataract surgery should be considered.
The only other option for treatment of cataracts is cataract surgery.
In cataract surgery, the cloudy lens is removed from the eye through a surgical incision. In most cases, the natural lens is replaced with a permanent intraocular lens (IOL) implant.
Before the development of small incision cataract surgery and intraocular lens implants, outcomes with cataract surgery were far inferior to outcomes today. Therefore, ophthalmologists would typically wait until a cataract was very advanced before offering surgery. Today, with advanced surgical techniques and equipment, cataract surgery can be offered at a much earlier stage. In fact, many ophthalmologists will agree that it is safer to proceed with cataract surgery at an earlier stage of development rather than waiting until the cataract is advanced and very dense.

Refractive errors:
For you to see clearly, light rays must be focused by the cornea and lens to fall precisely on the retina, a layer of light sensing cells that lines the back of the eye. The retina converts the light rays into impulses that are sent through the optic nerve to the brain, which interprets them as images. This process is very similar to the way a camera takes a picture. The cornea and lens in your eye act as the camera lens. The retina is similar to the film. If the image is not focused properly, the retina or film receives a blurry image. This condition in the human eye is known as a refractive error. There are three types of refractive errors that can be corrected or reduced by refractive surgery.

Myopia
Myopia or nearsightedness is a refractive error that causes poor distance vision. If your eye is too long, or your cornea has too much focusing power, images focus in front the retina. If you have myopia, light rays have past the correct focal point by the time they reach the retina. The retina then sends this "over-focused," blurry image to the brain. This condition affects over 25% of all people in the United States.
Hyperopia
Hyperopia or farsightedness is the opposite of myopia. Distant objects are clear and close up objects appear blurry. This condition is a result of a eye that is too short or a cornea that lacks the necessary refractive power to focus images on the retina. If you have hyperopia, images focus on a point beyond the retina. This unfocused image captured by the retina is then sent to the brain and processed as an unclear picture.
Astigmatism
Astigmatism is a condition which blurs and distorts both distant and near objects. A normal cornea is round with even curves from side to side and top to bottom. If you have astigmatism, your cornea is shaped more like the back of a spoon, curved more in one direction than in another. Light rays have more than one focal point and focus on different areas of the retina.
Presbyopia (Aging eyes):
Presbyopia is a normal condition after the age of 40, the lens becomes more rigid and can´t change shape as easily as it once did, it is more difficult to read at close range.

Eye glasses or contact lenses are the most common methods of correcting refractive errors. They work by refocusing light rays on the retina, compensating for the shape of your eye. Refractive surgery is also an option to correct or improve your vision by permanently changing the shape of the cornea, adjusting the eye´s focusing ability.

Pterygium
A pterygium is fleshy tissue that grows over the cornea, It may remain small or may grow large enough to interfere with vision. Pterygium occurs more often in people who spend a great deal of time outdoors, especially in sunny climates. UV radiation (usually from sunlight) is the most common cause of pterygium. This explains why pterygium occurs with increasing frequency in climates approaching the equator. Other causes include continuous exposure to dry, dusty environments. People who spend significant time in water sports (surfing or fishing) are particularly susceptible to pterygium because of the intense exposure to UV that occurs in these environments. When the eye is continuously assaulted by UV rays, the conjunctiva may thicken in a process similar to callus formation on the skin. The sensitive structures of the outer eye often can not comfortably tolerate this degenerative process, and irritation, redness, foreign body sensation, and ocular fatigue can result. The best method of preventing pterygium is to regularly wear UV 400 rated sunglasses when outdoors in sunny conditions. Sunglasses with a wrap-around design provide better protection than those with large gaps between the sunglass frame and the skin around the eyes. Wearing a hat with a wide brim provides valuable additional protection.When a pterygium becomes red and irritated, eyedrops or ointments may be used to help reduce the inflammation. If the pterygium is large enough to threaten sight, it is a cosmetic problem, or grows rapidly, it can be removed surgically. The best way to avoid recurrence is proper surgical removal and conjuntiva´s stem cells graft. In pterygium surgery, the abnormal tissue is removed from the cornea and sclera (white of the eye). Over the years, pterygium surgery has evolved significantly, and modern pterygium surgery has a significantly higher success rate than conventional surgery. In traditional "bare sclera" pterygium removal, the underlying white of the eye (sclera) is left exposed. Healing occurs over two to four weeks with mild to moderate discomfort. Unfortunately, the pterygium may grow back in up to 50% of patients. In many cases, the pterygium grows back larger than its original size. Most cornea specialists today perform pterygium surgery with a conjunctival autograft because of a reduced risk of recurrence. In this technique, the pterygium is removed, and the cornea regains clarity. However, the gap in the mucous membrane (conjunctiva) tissue, where the pterygium was removed, is filled with a transplant of tissue that has been painlessly removed from underneath the upper eyelid. Although the procedure requires more surgical skill than traditional surgery, this "auto-graft" (self-transplant) helps prevent re-growth of the pterygium by filling the space where abnormal tissue would have re-grown. The autograft is held in place with tiny stitches that may dissolve after a few weeks or can be removed in the surgeon's office. Stitches on the eye frequently cause discomfort, however, after pterygium/autograft surgery. The desire for a quicker, more painless recovery has led to the development of no-stitch pterygium/autograft surgery.

Glaucoma
Glaucoma is a disease of the optic nerve. Glaucoma damages nerve fibers, which can cause blind spots in our vision and vision loss to develop. Glaucoma has to do with the pressure inside the eye, or intraocular pressure (IOP). When the clear liquid called the aqueous humor--which normally flows in and out of the eye--cannot drain properly, pressure builds up in the eye. The resulting increase in IOP can damage the optic nerve. Most people who develop glaucoma notice no symptoms until their vision is impaired. Your ophthalmologist may tell you that you are at risk for glaucoma if you have one or more risk factors, including elevated IOP, a family history of glaucoma, a particular ethnic background, advanced age, or certain optic nerve conditions. Regular examinations with your ophthalmologist are important if you are at risk for this condition.

Retinal disease:
Diabetic retinopathy :
It is a complication of diabetes that can cause severe vision loss or even blindness. This disease is a leading cause of blindness in American adults. It is caused by changes in the blood vessels of the retina. Blurred vision may occur when the macula - the part of the retina that provides sharp, central vision – swells from the leaking fluid. This condition is called macular edema. If new vessels have grown on the surface of the retina, they can bleed into the eye, blocking vision. Anyone with diabetes is likely to get diabetic retinopathy. The longer someone has diabetes, the more likely he or she will get diabetic retinopathy. Between 40-45 percent of those with diagnosed diabetes have some degree of diabetic retinopathy. All people with diabetes need to get a dilated eye exam at least once a year to detect diabetic retinopathy. Often there are not symptoms in the early stages of the disease. Vision may not change until the disease becomes severe. But, even in more advanced cases, the disease may progress a long way without symptoms. That is why regular eye examinations for people with diabetes are so important. The treatment of diabetic retinopathy include control of blood sugar level , control of blood pressure and decrease blood cholesterol, LASER surgery (retinal photocoagulation) and vitrectomy surgery in severe cases. Laser surgery and appropriate follow-up care can reduce the risk of blindness by 90 percent. However, laser surgery often cannot restore vision that has already been lost. That is why finding diabetic retinopathy early is the best way to prevent vision loss.

Retinal detachment:
A retinal detachment is a very serious problem that almost always causes blindness unless treated. The appearance of flashing lights, floating objects, or a gray curtain moving across the field of vision are all indications of a retinal detachment. If any of these occur, see an ophthalmologist right away. Retinal tears increase the chance of developing a retinal detachment. Fluid vitreous, passing through the tear, lifts the retina off the back of the eye like wallpaper peeling off a wall. Laser surgery or cryotherapy (freezing) are often used to seal retinal tears and prevent detachment. If the retina is detached, it must be reattached with surgery before sealing the retinal tear.

Age Related Macular Degeneration (AMD):
Age related macular degeneration (AMD) is one of the most common causes of poor vision after age 60. AMD is a deterioration or breakdown of the macula. The macula is a small area at the center of the retina. The visual symptoms of AMD involve loss of central vision. While peripheral (side) vision is unaffected, one loses the vision necessary for looking at detail. AMD seems to be part of aging. While age is the most significant risk factor for developing AMD, heredity, blue eyes, high blood pressure, cardiovascular disease, and smoking have also been identified as risk factors. AMD accounts for 90 percent of new legal blindness in the US.