The eye functions like a camera. Light rays enter the eye through the cornea (the clear front window), pass through the pupil (the hole in the center of the iris), and then through the lens, finally reaching the retina (the film) at the back of the eye.
When light rays land on the retina, they form an upside-down image. The retina converts the image into impulses that travel through the optic nerve to the brain, which converts them into upright visual images.
Vision is clear only if the cornea and lens correctly bend or "refract" the light rays and focus them on the retina. Blurry vision may be due to what is called a "refractive error" --- the failure of the cornea and lens to focus light properly.
Prescription eye glasses, contact lenses, and refractive surgery correct or improve refractive errors by focusing light rays closer to, or directly onto, the retina. More than 90 percent of our knowledge is obtained through our eyes making vision the most valued of the five senses. However, millions of people suffer from diseases, disorders or injuries to the eye.



Regular eye examinations should provide the basis for maintaining proper eye health as many eye diseases and disorders have no symptoms or early warning signs. However problems or injuries can occur suddenly and unexpectedly.

Almost all eye injuries can be prevented. Many sports and recreational activities, including tennis, baseball, basketball and racquetball, carry some risk of eye injury. Activities at home such as cooking and gardening, also may present eye injury risk. Use protective eyewear when participating in sports, using chemical cleaners or doing heavy yard work.
Do not look into a closed container of hot food (especially liquids) immediately after removal from a microwave oven as steam can burn the eyes.
Do not use eye medication prescribed for someone else.
Do not use another person's eye make-up and do not apply make-up in a moving vehicle.
When removing a cork from a bottle, wrap the cork in a towel and direct the bottle away from your face and away from others.
To minimize eyestrain associated with extensive computer monitor use: blink frequently; change your body, head and eye position often; place reference material as close to the screen as practical to reduce head and eye movements; and minimize glare and reflections from office lighting.
Be aware of cigarettes or cigars in your hand when around children.
Keep chemicals, spray cans, adhesives, scissors, knives, forks, keys, pens and pencils away from young children.
If you experience an eye injury, sudden pain, loss of sight, flashing lights, an increase in floaters or other changes in your vision, visit your eye care professional immediately.



In America today:

80 million people have potentially blinding eye disorders.
14 million people have severe visual conditions not correctable by glasses.
14 million diabetics risk loss of sight.
12 million people have motor sensory diseases such as amblyopia and strabismus.
11 million people experience corneal disorders such as herpes and dry eye.
10 million people suffer visual loss caused by macular degeneration. Age-related macular degeneration (AMD) is the chief cause of blindness among Americans over 50 - and South Florida has the largest concentration of AMD patients over the age of 65.
5.5 million people have cataracts that obstruct vision.
2.8 million people are colorblind.
2.3 million people endure visual losses from inflammatory diseases such as uveitis.
2 million people are visually impaired from glaucoma.
1 million people are legally blind.

LASIK. A word bandied about for years now. While most people know that it means going from wearing glasses or contacts to not wearing glasses or contacts, most people don't really know what LASIK is.

LASIK is an acronym that stands for Laser Assisted In situ Keratomileusis. Basically, it is a procedure that permanently changes the shape of the cornea (the clear cover on the front of the eye) using an excimer laser.

An excimer laser is an ultraviolet laser that is used in refractive surgery to remove corneal tissue.

Wow. This is still just really too scientific. Let's try to put it in layman's terms, shall we?

LASIK surgery changes the way light is refracted or bent through your cornea so you can see more clearly and, almost always, without the use of glasses or contacts.

The actual procedure is pretty short and simple. To begin with, you relax in a reclining chair while numbing drops are put in your eyes. Once the drops have taken effect, a special device is used to gently hold your eyes open so you don't blink during the procedure. Next, the LASIK surgeon cuts a small flap from the top of the cornea.

All the information you and your doctor discussed prior to your exam was entered into a computer connected to the excimer laser. That customized program is used as the laser quickly reshapes your cornea. Once that's done, the LASIK surgeon puts the flap back down so it can seal and heal all by itself. No stitches required. And that's it. From start to finish, the entire process only takes about 15 minutes per eye.

The morning after your LASIK procedure, you will probably be at about 90% for improved vision and you can go to work if you want to. The other 10% improvement will happen over the following two to three weeks, as the eye recovers from being worked on.

LASIK surgery has helped lots of people with truly poor vision see clearly again. Instead of having to grab your glasses before you are even able to get out of bed and walk around each morning, you may very well be able to open your eyes and see clearly all by yourself.

If you wear glasses or contacts, you owe it to yourself to find out how LASIK surgery can improve your view of Indianapolis every day. Besides, think how great it would be to buy lots of cool sunglasses right off the rack instead of having to change from sun to regular every time you go outside.

Glossary of Ophthalmology Terms

Amblyopia: Reduced visual acuity in a normal eye not correctable with glasses, sometimes called a "lazy eye" and often associated with strabismus.

Anterior Chamber: The space between the cornea and the lens, which contains aqueous humor.

Astigmatism: This condition occurs when the cornea is not perfectly spherical and has an irregularity. The visual image is distorted so the parts are more in focus in one plane than in another; it is correctable with glasses. Astigmatism is often combined with myopia or hyperopia.

Cataract: Crystalline lens that is no longer clear or transparent, but is partially or completely opaque.

Choroid: The very vascular middle layer of the eye between the retina and the sclera that nourishes the outer portions of the retina. The choroid contains a pigment that absorbs excess light to prevent blurring of vision. The choroid has one of the highest blood flows in the body.

Ciliary Body: The part of the eye that connects the choroid to the iris. It produces aqueous fluid that fills the front part of the eye and thus maintains the eye pressure. It also allows focusing of the lens.

Cone Cells: One of the two types of light-sensitive cells in the retina of the eye. The human retina contains six to seven million cones; they function best in bright light and are essential for acute vision.

Conjunctiva: A thin lining over the sclera, or white part of the eye. This also lines the inside of the eyelids. Cells in the conjunctiva produce mucous, which helps to lubricate the eye.

Contact Lens: A small, bowl-shaped removable plastic lens that rests directly on the eye, in contact with the cornea or the sclera or both; ordinarily used to correct refractive errors, either with or instead or eye glasses.

Cornea: The transparent circular part of the front of the eyeball, structurally continuous with the sclera. It refracts the light entering the eye onto the lens, which then focuses onto the retina. The cornea is responsible for focusing light rays to the back of the eye.

Crystalline Lens: The flexible structure behind the iris that focuses the light rays to form an image onto the retina. When the lens does not focus properly, another lens has to be worn to supplement the cornea-lens focusing system. When the lens loses its transparency, the resulting condition is called a cataract.

Diabetic Retinopathy: A deterioration of retinal blood vessels in diabetic patients that can lead to vi sion loss.

Extraocular muscles: Six muscles control eye movement. Five of these originate from the back of the orbit and wrap around the eye to attach within millimeters of the cornea. Four of these move the eye up, down, left and right. Two muscles, (one originating from the lower rim of the orbit), control the twisting motion of the eye when the head is tilted.

Eyelid: the skin-covered structure that protects the front of the eye; limits light entering the eye; and spreads tears over the cornea.

Fluorescein Angiography: A diagnostic test by which the veins deep inside the eye are examined. A dye is injected into a vein in the arm and circulated by the blood to the back of the eye, allowing for clearer examination.

Fovea: Center of the macula, providing the most acute vision.

Fundus: The concave interior of the eye, consisting of the retina, choroid, sclera, optic disc and blood vessels, seen by means of the ophthalmoscope.

Glaucoma: An ocular disease characterized by an unstable or sustained increase of the pressure inside the eye.

Iris: The colored part of the eye. The iris is elastic pigmented tissue in front of the lens that regulates the amount of light that enters the eye. The opening in the center of the iris is the pupil. The iris contains muscles that open or close the pupil in response to the brightness of surrounding light. The iris acts like a camera shutter and controls the amount of light that enters the eye.

Keratoplasty (Corneal graft or transplant): Surgical replacement of an opaque or damaged cornea with a clear donor cornea, usually provided by eye banks, to allow a clear window through which a person can see again.

Lacrimal Apparatus: The part of the eye that produces tears to lubricate the eyes and continually wash out small particles of dirt and dust.

Laser:Focused high-energy light used for photocoagulation.

LASIK:Laser Assisted In-Situ Keratomilieusis is a refractive procedure in which an excimer laser ablation is performed under a superficial flap on the cornea to correct refractive errors, including myopia and astigmatism.

Lens: The clear part of the eye behind the iris that helps to focus light on the retina. The lens sits behind the iris and in front of the vitreous humor. Normally clear, a cataract forms when the lens becomes cloudy. (See also Crystalline lens.)

Intraocular Lens: A permanent lens surgically placed behind the pupillary opening to replace the crystalline lens following a cataract extraction.

Macula: An oval area in the retina on the back of the eye where the photoreceptors are most dense. The center of the macula is called the fovea. The macula is responsible for the central (or reading vision.) The macula has the greatest concentration of cone cells, and when the eye is directed at an object, the part of the image that is focused on the fovea is the image most accurately registered by the brain. It provides the best visual acuity in light, thus allowing one to also see in color.

Macular Degeneration: Degeneration of the macula which results in the loss of central vision, the type of vision necessary for driving, reading and recognizing faces. Can develop into a wet form or a dry form.

Muscles, Extraocular: The six muscles that move the eyeball: four rectus muscles produce vertical and horizontal motion; two oblique muscles keep the eyes vertical when the head tilts.

Myopia: This condition occurs when an object is focused by the crystalline lens in front of the retina rather than on the retina. Distant objects are not seen as clearly as nearby objects; therefore, it is also called near-sightedness.

Neuro-Ophthalmology: The sub-specialty that treats the nervous and vascular systems that involve the eye.

Ophthalmologist: A medical doctor who surgically and medically treats the structures, the functions, and the diseases of the eye and its appendages.

Optic Disc: The portion of the optic nerve also found on the retina of the eye. The optic disc identifies the start of the optic nerve where messages from cone and rod cells leave the eye via nerve fibers to the optic center of the brain. This area is also known as the "blind spot."

Optic Nerve: Located on the back of the eye and attached to the retina, this nerve receives impulses from the retina and relays them to the brain. The optic nerve leaves the eye at the optic disc and transfers all the visual information to the brain.

Optician: One who designs or manufactures optical instruments and/or ophthalmic prescriptions, or one who fits and adapts glasses or contact lenses.

Optometrist: An optometric doctor who provides primary eye care; diagnoses, treats and manages eye diseases and disorders; determines the ability to focus and coordinate the eyes, to judge depth and to see color accurately.

Orbit: The boney socket containing the eye, fat, extraocular muscles, nerves and blood vessels.

Orthoptics: A treatment of exercises designed to help the eye muscles work together to improve visual perception.

Photocoagulation: The focusing of powerful light rays onto tiny spots on the back of the eye, producing heat which seals retinal tears and cauterizes small blood vessels.

Photoreceptors: The microscopic light-sensitive cells that are located in the retina called rods and cones. There are approximately 7 million cones and 130 million rods.

Pupil: The circular opening in the center of iris through which light passes into the lens of the eye. The iris muscles control the size of the pupil. The pupil appears as the black circle in the center of the eye.

Retina: The light sensitive inner lining of the eye that sends electrical impulses to the brain. The retina contains millions of photoreceptor cells that receives light rays, processes them, and sends signals to the brain via the optic nerve. The retina works like the film in a camera. The retina is composed of light sensitive cells knows as rods and cones. The human eye contains about 125 million rods which are necessary for seeing in dim light; and between six million to seven million cones that are needed to see sharp accurate images and colors.

Retinal Detachment: This occurs when a part of the retina detaches from the choroid, causing it to lose contact with one of its primary sources of nutrition - resulting in loss of vision.

RK: Radial Keratotomy is an older procedure to correct mild to moderate myopia, whereby making a series of spoke-like incisions around its periphery flattens the cornea.

Rod Cells: One of the two types of light-sensitive cells in the retina of the eye. There are about 125 million rods, which are necessary for seeing in dim light.

Sclera: The white part of the eye, a tough covering with which the cornea forms the external protective coat of the eye.

Slit-Lamp: An instrument producing a slender beam of light for illuminating the structures of the eye, used to examine the external and internal parts of the eye.

Strabismus: This condition occurs when the muscles of the eye are misaligned and binocular vision is not present.

Uveal tract: A group of similar eye structures including the choroid, ciliary body and iris. May be prone to inflammatory conditions.

Ultrasonography: Recordings of the echoes of ultra-sound waves sent into the eye and reflected from the structures inside the eye or orbit. It allows one to detect and localize tumors and retinal detachments.

Vitreous Humor: A jelly-like, colorless, transparent substance that fills the largest chamber of the eye between the lens and the retina.

Vitrectomy: The surgical removal of diseased vitreous humor, or vitreous that has lost its transparency and does not allow light to reach the retina.

Diagnostic Testing

Patients visiting Al O’youn Al Dawli for a comprehensive eye exam may undergo one or more of the following tests or hear some of these terms:

20/20: Used to describe "normal vision". If you can read the 20/40 line, that means that at 20 feet, you can see what a person with normal vision can see at 40 feet.

Amsler grid : a simple screening test used to assess central vision, at the macula. The Amsler grid looks like graph paper - a series of small squares - with a dot in the center of the grid. The patient is instructed to stare at the dot and notice if any lines appear wavy or missing.

Corneal topography : produces detailed information about the curvature of the cornea. Computer software is used to measure and analyze the surface of the cornea and generate a color map from the data. The data is helpful to evaluate and plan to correct astigmatism, monitor corneal disease and detect irregularities in the shape of the cornea. Accurate measurement of astigmatism is important for refractive surgery, contact lens fitting and calculating the power of intraocular lenses.

Fluorescein angiogram: is useful for evaluating various disease effects on the retina. The test requires an injectable dye (fluorescein), specialized camera with filters, and timing. The dye is injected into the patient's arm; within seconds, the dye travels to the blood vessels inside the eye. Photographs are taken to document any fluid leakage as the dye circulates through the eye. A digital camera is often used which allows the physician to interpret the results immediately.

Fundus photography : may be ordered by your physician to document the status of the optic nerve, macula, retina, blood vessels and the vitreous. Specialized cameras are used to document the progression of diseases such as macular degeneration, glaucoma, and diabetic retinopathy.

Gonioscopy : used to examine the anterior chamber angle, the portion of the eye that directs aqueous humor (the fluid produced by the eye). Gonioscopy is a standard part of a glaucoma evaluation. A special mirrored contact lens is used during this evaluation.

Indocyanine Green Dye (ICG): is used to evaluate the choroidal circulatory system, just behind the retina. ICG reacts to light with a longer wavelength than fluorescein dye, allowing the doctor to determine exactly where, and if, the vessels are leaking. The ICG dye takes about 15 to 20 seconds to travel through the bloodstream to the eye. The digital photos are interpreted by the physician. If treatment is needed, the photos indicate where the laser treatment needs to be directed.

Keratometry: the measurement of the steepest and the flattest surfaces of the cornea. Accurate measurements are easily obtained from most eyes with a keratometer. Corneal topography is used to obtain more corneal details, or when reliable keratometry measurements cannot be obtained. Corneal measurements are an important component in formulas used to calculate and determine the power of intraocular lenses and in the fitting of contact lenses.

Ophthalmoscopy: is performed with an ophthalmoscope and allows the ophthalmologist to examine the retina and vitreous. Opthalmoscopy is usually performed with dilated pupils, to allow the best view inside the eye. Two types of ophthalmoscopes may be used: direct and indirect. The direct ophthalmoscope has a battery powered light source and is hand-held. Multiple lenses may be selected with a dial, which allows the doctor to focus on and view the optic nerve and the central retina. The periphery, or entire retina, may be viewed by using an indirect ophthalmoscope, which is worn on the doctor's head. A lens is placed in front of the patient's eye while the doctor looks through the magnifying glasses in the headgear. The combination of the instrument and the lens allows a good view of the entire retina.

Optical Coherence Tomography : Co-invented by Bascom Palmer Chairman Dr. Carmen Puliafito, the technique of optical coherence tomography (OCT) produces high resolution, high speed, non-invasive, cross-sectional images of body tissue. The technology is best compared to ultrasound, except that it employs light rather than sound and thereby achieves clearer, sharper resolution. Non-invasive OCT examinations produce real-time cross-sectional images of retinal tissue, in ophthalmic applications, and are usually accomplished in less than 10 minutes. Thanks to OCT's high resolution, which is 10 times greater than magnetic resonance imaging (MRI) or ultrasound, microscopic early signs of disruption in tissues can be detected and treated. The ophthalmic applications have already benefited patients with glaucoma, retinal and macular diseases and those considering corneal and refractive surgery.

Photopter (or refractor): Device, placed in front of a patient's eyes, as they are asked to read an eye chart on the wall. The photopter contains various lenses that are changed by the examiner until the best corrected vision is determined. The eye chart on the wall used to be placed 20 feet in front of the patient, which meant the room had to be at least 20 feet long. Today, the distance has been modified by using mirrors to reflect the images, but they still appear to be 20 feet away.

Slit lamp examination: performed using a slit lamp, which is an instrument with a high-intensity light source that can be focused and narrowed. The structures in the front section of the eye are examined: the eyelids, the cornea, anterior chamber, the surface of the sclera, the iris, and the crystalline lens.

Tonometry : A tonometer or a tonopen may be used to measure the intraocular pressure (pressure within the eyes). It is used to screen for glaucoma. It is a good idea to have the intraocular pressure checked routinely after the age of 40, or if you are at a high risk for developing glaucoma.

Ultrasound (echography) : is used in ophthalmology when a cloudy cornea, a dense cataract, or blood in the vitreous obscures a view into the eye with an ophthalmoscope. Standardized ultrasound also may be used to evaluate the extent and location of a retinal detachment, to determine the exact borders and height of intraocular or orbital tumors; to determine the axial eye length (the distance from the outer cornea to the macula); and the thickness of extraocular muscles. B-scan ultrasound produces a two-dimensional, cross-sectional image; A-scan produces a one-dimensional view. It is appropriate to obtain an A-scan on patients before cataract surgery to determine the appropriate power of the intraocular lens implant.

Visual acuity testing: Although it is a simple exam, it is an important component of a comprehensive eye exam. An eye exam measures a person's ability to see an object at a specified distance. The results of an eye exam determine if a person has normal vision or if a prescription for glasses or contact lenses would help put things into proper focus.

Visual field testing : monitors peripheral vision. Visual fields are obtained to monitor visual changes that may be caused by specific eye diseases, such as glaucoma, as well as the neurological function of the retina, optic nerve and brain. There are different types of visual field exams, usually they require the patient to focus on one spot and respond to flashing lights by pressing a button.

Visual Field within Normal Limits

Visual Field outside Normal Limits

What are the symptoms of cataracts?
What are the different types of cataracts?
What can one expect during cataract surgery?
Are lasers used during cataract surgery?


"Cataract" is the name used to describe a condition wherein the lens of the eye becomes opacified or cloudy blocking some light from reaching the retina and interfering with vision. Cataracts are multi-faceted. We don't know all the causes, but we do know that time, aging, and hereditary factors all play a role in cataract development.
Cataract formation can be accelerated by trauma, diabetes, sunlight, and certain medications. Typically, cataracts occur in adults ("adult onset"), but may occur as a congenital disorder. More than half of all Americans age 65 and older have a cataract.


Early signs of cataracts include blurred or cloudy vision; frequent changes in eyeglass or contact lens prescriptions; night glare and hazy vision; and colors that seem to fade. An ophthalmologist must determine if these symptoms are really caused by a cataract or by some other eye problem that may need treatment.
For an adult, a cataract should be removed only when it interferes with lifestyle and makes it difficult to continue normally enjoyable activities. Generally, there is no such thing as a cataract being "ripe" or "not ripe" for removal. What matters is whether or not the problem interferes with vision. In rare instances, a "hyper-mature" cataract may cause elevated eye pressure or inflammation of the eye. In this case, it must be removed immediately. Otherwise, removal of a cataract is at the patient's discretion.


Age-related cataract: Most cataracts are related to aging.
Congenital cataract: Some babies are born with cataracts or develop them in childhood, often in both eyes. These cataracts may not affect vision. If they do, they may need to be removed.
Secondary cataract: Cataracts are more likely to develop in people who have certain other health problems, such as diabetes. Also, cataracts are sometimes linked to steroid use.
Traumatic cataract: Cataracts can develop soon after an eye injury, or years later.


Cataract surgery is the most frequently performed surgery in the United States - and the most successful. Over 95 percent of those who have cataract surgery regain vision levels between 20/40 and 20/20.
Cataract surgery usually lasts less than one hour and is almost painless. Many people choose to stay awake during surgery and have an anesthetic to numb the nerves in and around the eye.
A lens implant (intraocular lens) inserted during cataract surgery gives the surgeon an opportunity to correct nearsightedness or farsightedness. Current research on intraocular lens implants also may provide high quality correction for astigmatism and for both bifocal and multi-focal vision. Bifocal implants are currently used, but physicians have yet to achieve consistently satisfactory outcomes.
The time required for recuperation after cataract removal depends on the type of procedure performed and the patient's individual rate of healing. The decision as to which procedure is best for an individual's eye is made by the patient's ophthalmologist.
One technique ophthalmologists use is phacoemulsification. This procedure involves making a tiny incision, about 2.5 to 3.5 millimeters in length. A pencil-like instrument, inserted through the opening, is used to emulsify (breakdown into tiny pieces) and aspirate the clouded lens material. Then the intraocular lens is inserted into place.

Other techniques include:


In some cases after cataract surgery, a haziness develops in the membrane or capsule supporting the intraocular lens implant. When this happens, a laser is sometimes used to create a small opening in the membrane (a capsulotomy) through which the patient can see clearly. Lasers are used because they are able to make a small, very precise opening.


During the past three decades, the techniques and results of cataract surgery in the U.S. have changed dramatically:


Despite these advances, however, U/S phacoemulsification techniques are not without potential sight-threatening complications.

Possible complications related to U/S phacoemulsification include corneal or scleral burn, iris trauma, rupture of the posterior capsule, loss of vitreous fluid, cystoid macular edema, and induced astigmatism. These complications may lead to compromised vision prompting investigations into newer techniques of using laser energy to remove cataracts.
The advantages of using a laser to remove cataracts include the ability to use fiber optics with a smaller diameter than typical ultrasonic probes; and direct energy precisely on target tissue by means of a smooth, blunt, stationary probe.
Theoretically, the use of a laser, compared with U/S phacoemulsification:

What are the common types of glaucoma? What are the risk factors for glaucoma? FAQs about glaucoma What is the treatment for glaucoma?

Glaucoma is a family of more than 30 diseases that affects pressure within the eye, damaging the optic nerve. When pressure inside the eye increases, blind spots in peripheral areas of vision may occur. Of all conditions and diseases of the eye, glaucoma is one of the leading causes of blindness in the United States. Often called the "sneak thief" of sight, most forms of glaucoma do not produce symptoms until vision is already severely damaged. But if diagnosed early, the disease can be controlled and permanent vision loss can be prevented.

What are the common types of glaucoma?

• Acute Angle Closure Glaucoma: acute closure of the peripheral drainage angle, characterized by a sudden increase in intraocular pressure.
• Chronic Angle Closure Glaucoma: the iris obstructs the eye's drainage angle in a slow, progressive fashion.
• Primary Open Angle Glaucoma: the drainage angle is open but does not allow fluid to drain adequately for unknown reasons.
• Pseudoexfoliation Glaucoma: deposits of a fibrillary material obstruct drainage of fluid from the eye.
• Pigmentary Glaucoma: pigment dislodged from the iris obstructs the eye's drainage structures.
• Angle Recession Glaucoma: scar tissue from previous trauma obstructs the outflow of fluid.
• Neovascular Glaucoma: various disorders cause blood vessels to proliferate on the iris and in the eye's drainage structures.
• Congenital Glaucoma: the eye's drainage channels form abnormally during gestation.

What are the risk factors for glaucoma?

Although glaucoma is most common in adults over the age of 40, susceptibility is not determined by age alone. There is a genetic component, and those with a family history of the disease, as well as African-Americans, are at increased risk. Those with hypertension, diabetes and other systemic diseases are also at risk. Studies have shown individuals at greater risk for glaucoma may fit one or more of the following criteria:

• are over the age of 60
• have a family history of the disease, elevated intraocular pressure
• are African-American over the age of 40
• have diabetes or hypertension
• are nearsighted

Since early detection is critical to avoiding permanent loss of vision, individuals who possess any of the non-age-related risk factors should have regular examinations by an ophthalmologist every one or two years.

Individuals in the general population should have a glaucoma evaluation every two or three years after the age of 40, and every one or two years after the age of 60.

What is the treatment for glaucoma?

Glaucoma treatment seeks to decrease intraocular pressure and prevent damage to the optic nerve. Different types of glaucoma require different therapies to prevent further damage to the eye's structures. At the beginning of treatment, the doctor will generally recommend medication or a combination of medications for the specific condition. Therapies may include:

• Eye drops (or a combination of eye drops and pills) to reduce intraocular pressure. Several different classes of glaucoma medications are available to provide pressure reduction including beta blockers, prosaglandin analogues, alpha adrenergic agaonists, miotic, epinephrine compounds, and oral and topical carbonic anhydrase inhibitors. These medications work by either reducing the rate at which fluid in the eye is produced or increase the outflow of fluid from the eye.
• Laser treatment to open the drainage angle and reduce intraocular pressure.
• Surgery to create a new passage for fluid drainage. Surgery is usually reserved for cases that cannot be controlled by medication and following appropriate laser treatment.

Frequently Asked Questions About Glaucoma

Is blindness due to glaucoma preventable?

Regular diagnostic examinations by an ophthalmologist are the key to preventing loss of vision due to glaucoma. Ophthalmologists are medical doctors, specialists in eye care and trained to examine and treat eye diseases. Although there is no way to reverse damage, if glaucoma is diagnosed and treated early, blindness almost always is preventable.

What are the symptoms of glaucoma?

Although the blindness associated with this disease is preventable, more than one million people in the United States have some glaucoma-related vision loss. In most cases, glaucoma is asymptomatic (has no symptoms). By the time an individual experiences decreased vision, the disease is frequently in its latter stages. Since early warning signs of glaucoma are rare, it is important --- especially for those at risk --- to have medical eye examinations at appropriate intervals, as described in this section.

Symptoms depend on the type of glaucoma the individual has.

• Those who have chronic glaucoma may not be aware of any symptoms because the disease develops slowly and patients rarely notice loss of peripheral vision.
  
  
• Those who have an acute form of glaucoma may develop severe symptoms because ocular pressure rises quickly and they may experience:
  • Blurred vision, especially at night
  • Halos or rainbows around lights
  • Severe headaches or eye pain
  • Nausea

How does glaucoma affect the eye?

The eye has an internal pressure created by production of a clear fluid called aqueous humor. This fluid circulates through the eye and exits through the anterior chamber angle and ultimately drains into the blood stream. In glaucoma, the aqueous humor outflow is obstructed, resulting in increased eye pressure and, eventually, optic nerve damage.

What is the cornea?	What are refractive errors?
What infections, injuries and irregularities affect the cornea?	What about LASIK?
What is a corneal transplant?	What are cataracts?
What is conjunctivitis?	What is dry eye?
What is a pterygium?

Corneal and external diseases involve the cornea , anterior chamber of the eye, iris, lens, conjunctiva and eyelids, including cataracts; corneal allergies, infections and irregularities; refractive errors (nearsightedness, farsightedness and astigmatism); conjunctivitis (pink eye); dry eye; tear disorders; keratoconus; pterygium; endophthalmitis; Fuch's Dystrophy and many others.


The cornea is the transparent, dome-shaped, outermost layer that covers the iris and pupil in the front of the eye. Corneal tissue consists of five basic layers: epithelium, Bowman's layer, stroma, Descemet's membrane and endothelium. Although the cornea is clear, it contains a highly organized group of cells and proteins. Unlike most tissues in the body, the cornea contains no blood vessels to nourish or protect it against infection. Instead, the cornea receives its nourishment from the tears and aqueous humor that fill the chamber behind it.

The cornea, one of the protective layers of the eye, serves two functions:
To see clearly, the cornea and lens must focus the light rays precisely on the retina. This refractive process is similar to the way a camera takes a picture. The cornea and lens in the eye act as would a camera's lens. The retina approximates the film. If the cornea is unable to focus the light properly, then the retina receives a blurry image.








Some trauma, including projectile foreign bodies, lacerations and blunt trauma can cause scarring that clouds the cornea. Hereditary conditions including degenerations and dystrophies may also cloud the cornea. The most common hereditary condition seen in young people is keratoconus, a condition in which the cornea assumes a cone shape. This is common in children with Down's syndrome and in people with allergic conjunctivitis. These patients may be able to use contact lenses or glasses for a period of time, but may eventually develop scarring and high astigmatism that cannot be corrected without corneal transplantation.
Occasionally, it may become necessary to perform a corneal transplant following cataract surgery, if bullous keratopathy occurs. Bullous keratopathy is a condition where the endothelial cells on the back of the cornea decrease in number after cataract surgery. However, this is less common today because of new techniques and improved lens design.


The eye surface can be severely damaged by a number of problems, including: These problems can result in extensive damage on the eye surface, leading to new blood vessel formation and scarring --- damage which results in loss of vision.


Corneal transplants are one of medicine's most successful transplant operations. In the past 35 years, more than 250,000 corneal transplants have been performed in the United States
.








For many individuals, a corneal transplant may be the only hope for restored vision, and may be necessary when the cornea is cloudy or damaged due to disease, injury, accident, or hereditary conditions. In these situations, the cornea must be removed and replaced with healthy donor tissue. The procedure is successful in 90 percent of cases, restoring sight and, in some cases, even providing sight for the first time.
Today, regrafts are one of the most common reasons for corneal transplants. Regrafts occur when a patient needs a second corneal transplant because the first one was unsuccessful. Some additional reasons include:


The cornea and lens bend or refract light rays so they can be focused on the retina, the nerve layer that lines the back of the eye. The retina receives the picture formed by these light rays and sends the image to the brain through the optic nerve. A refractive error means that the shape of the eye does not allow the light to be properly refracted making images blurry. Refractive errors include:


Myopia (nearsightedness) occurs when light rays are focused in front of the retina instead of directly on the retina. Myopia is a vision problem experienced by approximately one-third of the population. When the eyeball is too long from front to back, the image of a distant object focuses in front of the retina, instead of directly on it. As a result, the distant object appears blurred. The more myopic the eye, the closer an object must be before it is in sharp focus. Nearsighted people have difficulty seeing objects at a distance, such as highway signs, but usually can see up-close for tasks such as reading or sewing.
Some people with myopia can use their natural nearsightedness to read without glasses at an age when other people must wear reading glasses. However, if they have refractive surgery to correct myopia, they may be able to see distant objects without glasses, but will probably need to wear glasses to read sometime after age 40, due to presbyopia .


Nearsighted people may experience headaches or eyestrain and might squint or feel fatigued when driving or playing sports. Patients who experience these symptoms while wearing glasses or contact lenses may need a comprehensive eye examination, as well as a new prescription.


Nearsightedness runs in families and usually appears in childhood. This vision problem may stabilize at a certain point, although sometimes it worsens with age. This is known as "myopic creep."
Non- surgical treatment options for myopia include glasses and contact lenses. Surgical treatment options include ALK, clear lens extraction, LASEK, LASIK, LASEK, phakic IOL and RK. While there are numerous surgical options available, not all individuals are good candidates for specific procedures. Patients should review these options in depth with their physicians prior to making any final decisions.


Hyperopia or farsightedness occurs when light rays are not bent enough to focus on the retina. Hyperopia is a common vision problem, affecting about one-fourth of the population. If the eye is too short from front to back, light rays reach the retina before they converge (focus). People with hyperopia can sometimes see distant objects very well, but may have difficulty seeing objects that are close.
Young eyes can sometimes compensate for this refractive error depending on age and the degree of hyperopia present. But with aging, the human lens loses this ability and a hyperopic person eventually may have difficulty seeing objects at a distance, as well as those that are nearby. In fact by age 40, even those with little or no refractive error will begin to experience difficulty focusing on close objects.


Farsighted people sometimes have headaches or eyestrain, and may squint or feel fatigued when performing work at close range. Patients who experience these symptoms while wearing glasses or contact lenses may need an eye exam and a new prescription.


Most children are born with hyperopia, but most of them "outgrow" it as the eyeball lengthens with normal growth. Sometimes people confuse hyperopia with astigmatism; both cause difficulty in seeing close objects, but have different causes.


Non-surgical treatment options include glasses and contact lenses. Surgical treatment options include clear lens extraction, CK, LASIK, LTK, phakic IOL, and PRK. While there are numerous surgical options available, not all individuals are good candidates for specific procedures. Patients should review these options in depth with their physicians prior to making any final decisions.


Regular astigmatism occurs when light rays are focused at more than one point on the retina. Astigmatism is the most common vision problem. It occurs when the cornea surface is not ideally rounded, but is curved more along one axis than the other --- that is, when the eye is shaped more like the side of a football than a basketball. Light entering the eye does not focus symmetrically on the retina. The result is astigmatism, which blurs both near and distance vision. This refractive error may occur in patients who are either myopic (nearsighted) or hyperopic (farsighted). There are various types of astigmatism included regular, mixed and irregular astigmatism.


Patients with only a small amount of astigmatism may not notice it or may have slightly blurred vision. Sometimes uncorrected astigmatism can cause headaches or eyestrain and distort or blur vision.
Eyeglasses or contact lens prescriptions with three parts indicate some amount of astigmatism. A prescription with three parts looks like this: -2.75 -1.25 x 180. The first part indicates the main spherical correction, while parts two and three show the extent and location of your astigmatism.


Currently, excimer lasers in the US are approved for treatment of regular and mixed astigmatism. Recent advances in technology now allow for the therapeutic treatment of induced irregular astigmatism. In the future, this application may be expanded to include all types of irregular astigmatism. Patients who believe they have astigmatism should discuss this subject in further detail with their physician to gain a better understanding of the mechanisms in their case.


With increasing age, the lens inside of the eyes loses the ability to focus on nearby objects. The problem usually manifests itself around age 40 and can be corrected with bifocals or reading glasses. This is a normal aging process, called presbyopia and all people develop.
Some people with myopia can use their natural nearsightedness to read without glasses at an age when other people must wear reading glasses. However, if they have refractive surgery to correct myopia, they will be able to see distant objects without glasses, but probably will need to wear glasses to read sometime after age 40 due to presbyopia.


Monovision is a method of distance vision correction to account for presbyopia. In monovision, refractive surgery is used to adjust one eye for "near" vision and the other eye for "distance" vision. Contact lenses or glasses may be required for best distance or night vision activities, including driving. This option is not suitable for everyone and a trial period of monovision using contact lenses may help decide if it is right for the patient.


This term describes a group of diseases that cause swelling, itching, burning, and redness of the conjunctiva, the protective membrane that lines the eyelids and covers exposed areas of the sclera, or white of the eye. It is caused by a virus which is very contagious and spreads easily. The virus may affect one or both eyes. At its onset, conjunctivitis is usually painless and does not adversely affect vision but can be uncomfortable. The body's defenses will clear viral conjunctivitis in one to three weeks, and medication is not always necessary. Cold compresses several times a day on the eyes may offer relief as may artificial tears and dark sunglasses.

But for some forms of conjunctivitis, treatment will be needed. If treatment is delayed, the infection may worsen and cause corneal inflammation and a loss of vision.



A pterygium is a triangular-shaped tissue growth, yellow-white to pinkish in color, on the nasal side of the cornea. It may become red, inflamed or advance toward the center of the eye. Some pterygia grow slowly throughout a person's life, while others stop growing after a certain point. A pterygium rarely grows so large that it begins to cover the pupil of the eye.
Pterygia are more common in sunny climates and in the 20-40 age group. Scientists do not know what causes pterygia to develop. However, since people who have pterygia usually have spent a significant time outdoors, many doctors believe ultraviolet (UV) light from the sun may be a factor. In areas where sunlight and wind is strong or dust is prevalent, wearing protective eyeglasses, sunglasses, and/or hats with brims are suggested.
It is a benign condition and will not spread to damage the internal part of the eye. Because a pterygium is visible, many people want to have it removed for cosmetic reasons. Lubricants can reduce the redness and provide relief from the chronic irritation.


"Cataract" is the name used to describe a condition wherein the lens of the eye becomes opacified or cloudy blocking some light from reaching the retina and interfering with vision. Cataracts are multi-faceted. We don't know all the causes, but we do know that time, aging, and hereditary factors all play a role in cataract development.
Cataract formation can be accelerated by trauma, diabetes, sunlight, and certain medications. Typically, cataracts occur in adults ("adult onset"), but may occur as a congenital disorder. More than half of all Americans age 65 and older have a cataract.


Early signs of cataracts include blurred or cloudy vision; frequent changes in eyeglass or contact lens prescriptions; night glare and hazy vision; and colors that seem to fade. An ophthalmologist must determine if these symptoms are really caused by a cataract or by some other eye problem that may need treatment.
For an adult, a cataract should be removed only when it interferes with lifestyle and makes it difficult to continue normally enjoyable activities. Generally, there is no such thing as a cataract being "ripe" or "not ripe" for removal. What matters is whether or not the problem interferes with vision. In rare instances, a "hyper-mature" cataract may cause elevated eye pressure or inflammation of the eye. In this case, it must be removed immediately. Otherwise, removal of a cataract is at the patient's discretion.


Age-related cataract: Most cataracts are related to aging.
Congenital cataract: Some babies are born with cataracts or develop them in childhood, often in both eyes. These cataracts may not affect vision. If they do, they may need to be removed.
Secondary cataract: Cataracts are more likely to develop in people who have certain other health problems, such as diabetes. Also, cataracts are sometimes linked to steroid use.
Traumatic cataract: Cataracts can develop soon after an eye injury, or years later.


Cataract surgery is the most frequently performed surgery in the United States - and the most successful. Over 95 percent of those who have cataract surgery regain vision levels between 20/40 and 20/20.
Cataract surgery usually lasts less than one hour and is almost painless. Many people choose to stay awake during surgery and have an anesthetic to numb the nerves in and around the eye.
A lens implant (intraocular lens) inserted during cataract surgery gives the surgeon an opportunity to correct nearsightedness or farsightedness. Current research on intraocular lens implants also may provide high quality correction for astigmatism and for both bifocal and multi-focal vision. Bifocal implants are currently used, but physicians have yet to achieve consistently satisfactory outcomes.
The time required for recuperation after cataract removal depends on the type of procedure performed and the patient's individual rate of healing. The decision as to which procedure is best for an individual's eye is made by the patient's ophthalmologist.
One technique ophthalmologists use is phacoemulsification. This procedure involves making a tiny incision, about 2.5 to 3.5 millimeters in length. A pencil-like instrument, inserted through the opening, is used to emulsify (breakdown into tiny pieces) and aspirate the clouded lens material. Then the intraocular lens is inserted into place.

Other techniques include:

In some cases after cataract surgery, a haziness develops in the membrane or capsule supporting the intraocular lens implant. When this happens, a laser is sometimes used to create a small opening in the membrane (a capsulotomy) through which the patient can see clearly. Lasers are used because they are able to make a small, very precise opening.


During the past three decades, the techniques and results of cataract surgery in the U.S. have changed dramatically:

Despite these advances, however, U/S phacoemulsification techniques are not without potential sight-threatening complications.

Possible complications related to U/S phacoemulsification include corneal or scleral burn, iris trauma, rupture of the posterior capsule, loss of vitreous fluid, cystoid macular edema, and induced astigmatism. These complications may lead to compromised vision prompting investigations into newer techniques of using laser energy to remove cataracts.
The advantages of using a laser to remove cataracts include the ability to use fiber optics with a smaller diameter than typical ultrasonic probes; and direct energy precisely on target tissue by means of a smooth, blunt, stationary probe.

Theoretically, the use of a laser, compared with U/S phacoemulsification:



Among the many different reasons for eye discomfort, by far the most common is "dry eye." This condition, characterized by unstable tear film, is distinct from other mechanical dysfunctions (i.e., blepharitis and blocked tear ducts) which have comparable symptoms but are less serious.
Prior to the development of explicit tests, a dry eye diagnosis often masked additional underlying dysfunctions which resulted in ineffective treatments. Now, with our ability to diagnose all abnormalities, there is new and valuable insight into the actual cause and effects of the disease. For example, it was previously assumed that the irritation suffered by dry eye patients was due to a lack of tears. Given new information,

Vitreo-Retinal Diseases

What are the retina and vitreous? What are the macula and the fovea? What is macular degeneration? What is diabetic retinopathy? What is a macular hole? What are retinal detachments and tears?

What is uveitis? What is CMV retinitis? What is retinopathy of prematurity? What is retinoblastoma? What is retinitis pigmentosa? What are flashes and floaters?

What are vitreo-retinal diseases?

A large variety of conditions can affect the vitreous and retina that lie on the back part of the eye that is not readily visible, such as diabetic retinopathy, macular degeneration, retinal detachments or tears, macular holes, retinopathy of prematurity, retinoblastoma, uveitis, eye cancer, flashes and floaters and retinitis pigmentosa.

What are the retina and vitreous?

The retina is an extension of the brain. It forms the interior lining of the eye and contains millions of light-sensitive nerve endings (rods and cones). The light rays that enter the eye though the cornea, then pass through the pupil, lens and vitreous ultimately focus on the retina which receives the light and transmits nerve impulses through the optic nerve to the brain, where a visual image is created.

Fluorescein angiogram of a normal retina.

Vitreous is a clear, gel-like substance that fills the cavity between the lens and the retina and serves vision by supporting the shape of the eye.

What are the macula and the fovea?

The central portion of the retina is the macula which provides central vision. The macula is composed of cones and rods. The cones allow us to see in bright light, to distinguish color, and to discern fine detail in reading and the rods are more sensitive to dim light and allow for night vision, but cannot distinguish either color or fine detail. Outside the macula, cones dwindle. The peripheral retina is made up primarily of rods, which provide peripheral vision both day and night.

In the center of the macula is the fovea, an area smaller than a pinpoint. It is composed entirely of cones. This tiny piece of the retina provides the sharpest vision --- the vision required to read. Everything we look at directly comes into focus at the fovea.

What conditions, diseases and irregularities affect the retina and vitreous?

The retina and vitreous can be affected by a large variety of conditions, including diabetic retinopathy, macular degeneration, retinal detachments or tears, macular holes, retinopathy of prematurity, flashes and floaters, retinoblastoma and retinitis pigmentosa.

What is diabetic retinopathy?

A person with diabetes is at risk for developing diabetic retinopathy among other ophthalmic disorders. Diabetic retinopathy is the leading cause of blindness in young and middle-aged adults today. The longer a person has diabetes, the greater their chance of developing diabetic retinopathy. There are two types of diabetic retinopathy:

• non-proliferative diabetic retinopathy (NPDR)
• proliferative diabetic retinopathy (PDR)

NPDR, also known as background retinopathy, is an early stage of diabetic retinopathy and occurs when the tiny blood vessels of the retina are damaged and begin to bleed or leak fluid into the retina resulting in swelling (diabetic macular edema) and the formation of deposits known as exudates. Many people with diabetes develop mild NPDR often without any visual symptoms.

Normal Retina

Non-Proliferative Diabetic Retinopathy

PDR carries the greatest risk of loss of vision and typically develops in eyes with advanced NPDR. PDR occurs when blood vessels on the retina or optic nerve become blocked consequently starving the retina of necessary nutrients. In response, the retina grows more blood vessels (neovascularization). Unfortunately these new vessels are abnormal and cannot replenish the retina with normal blood flow.

PDR may lead to any one of the following:

1. Vitreous hemorrhage - proliferating retinal blood vessels grow into the vitreous cavity and break down. Both the hemorrhaging and resultant scar tissue may interfere with vision.
2. Traditional retinal detachment - scar tissue in the vitreous and on the retina cause the retina to detach.
3. Tractional and rhegmatogenous retinal detachment - scar tissue creates a hole or tear in the retina causing it to detach.
4. Neovascular glaucoma - abnormal blood vessel growth on the iris blocks the flow of fluid out of the eye causing the pressure to increase and damaging the optic nerve.

What are the symptoms of diabetic retinopathy?

Generally, people with mild NPDR do not have any visual loss. A dilated eye exam is the only way to detect changes inside the eye before loss of vision begins. People with diabetes should have an eye examination at least once a year. More frequent exams may be necessary after diabetic retinopathy is diagnosed.

People with PDR experience a broader range of symptoms. They may:

• see dark floaters
• experience loss of central or peripheral vision
• experience visual distortions or blurriness
• experience temporary or permanent vision loss

How is diabetic retinopathy diagnosed?

Diabetic retinopathy is diagnosed by dilating the pupil and looking inside the eye with an ophthalmoscope. If an ophthalmologist discovers diabetic retinopathy, he or she may wish to order color photographs of the retina through a test called fluorescein angiography. During this test, a dye is injected into the arm and quickly travels throughout the blood system. Once the dye reaches the blood vessels of the retina, a photograph is taken of the eye. The dye allows the ophthalmologist to detect damaged blood vessels that are leaking dye.

Can diabetic retinopathy be prevented?

The most effective overall strategy for diabetic retinopathy is to prevent it as much as possible. Strict control of blood sugar levels will significantly reduce the long-term loss of vision from retinopathy. With improved diagnosis and treatment, only a small percentage of people with retinopathy develop serious vision problems.

What are the current treatment options for a person with diabetic retinopathy?

Because the earliest stages of diabetic retinopathy include inflammation, intraocular corticosteroids have been utilized with some success in selected patients. This form of treatment includes the use of a long-acting corticosteroid (triamcinolone acetonide) injected into the vitreous cavity by way of a very tiny needle under topical (drops) anesthesia. This treatment may reduce retinal swelling and improve visual acuity in patients with diabetic macular edema. However, visual recovery may be limited and the effect may last only 3 to 6 months after the treatment. Other clinical trials on corticosteroids include a sustained-release drug delivery device surgically implanted inside the eye to allow constant release of the medication. In two larger multicenter clinical trials using sustained-release steroid drug delivery devices, the Oculex Study is evaluating dexamethasone and the Bausch and Lomb Study is testing fluocinolone acetonide.

What research is currently being conducted on diabetic retinopathy?

Two new medications are currently being investigated for diabetic retinopathy. LY333531, a protein Kinase C-beta inhibitor (PKC-beta inhibitor) developed by Eli Lilly and Company, is a promising new medication for preventing the progression of diabetic retinopathy. A clinical trial on this medication does not yet have enough data to make a general recommendation to change current management strategies with laser surgery or pars plana vitrectomy. Similarly, Genetech is currently testing Anti-Vascular Endothelial Growth Factors (anti-VEGF) drugs for wet age-related macular degeneration. These anti-VEGF drugs may have future application for the treatment of diabetic retinopathy.

What is age-related macular degeneration?

In the western world, age-related macular degeneration (AMD) is the leading cause of legal, irreversible blindness among people 50 years of age and older.

• Dry macular degeneration (atrophic AMD) is the most common form of macular degeneration and can progress to cause severe central vision loss. This disease progresses slowly and most people usually maintain some central vision in at least one eye. The condition always starts as "dry" AMD. "Dry" AMD refers to the slow degenerative process that occurs without any formation of abnormal blood vessels. The recent Age-Related Eye Disease Study (AREDS) demonstrated that the progression of "dry" AMD could be slowed with vitamin supplementation. This study demonstrated the benefits of taking Vitamin C, Vitamin E, beta carotene, and zinc along with copper. Several vitamin preparations containing the appropriate amounts of these vitamins are currently available and we encourage patients with AMD to discuss these various vitamin preparations with their eye care specialist. Previous studies have also suggested that green leafy vegetables may be beneficial and smoking may be detrimental to patients with AMD.
• "Wet" macular degeneration (exudative or neovascular AMD) is caused by blood vessels growing under the retina in the macula. "Wet" AMD always arises from pre-existing "dry" AMD. These blood vessels leak fluid, protein, lipid and blood. Eventually, if untreated scar tissue forms under the macula and central vision is destroyed. Current treatments approved for "wet" macular degeneration include thermal laser therapy and photodynamic therapy with Visudyne®.

Normal Retina

Macular Degeneration

What are the symptoms of macular degeneration?

There is no pain associated with dry or wet AMD. The most common symptom of dry AMD is slightly blurred or fuzzy vision requiring greater illumination to see greater details. Also, an inability to recognize faces at a distance may develop.

As dry AMD progresses, a blurred spot develops in the center of vision. With time, the spot may get bigger and darker, reducing central vision. Often, when dry AMD is limited to one eye patients do not complain of visual changes because of the ability of the other healthy eye to see clearly, allowing for driving, reading, recognizing faces and seeing fine details.

Symptoms of wet AMD may be that straight lines, such as sentences on a page, appear wavy; rapid loss of central vision; and a blurred or blind spot in the center of vision.

How is macular degeneration diagnosed?

If an ophthalmologist suspects a patient of having AMD, he or she may:

• perform a visual acuity test to measure vision at a distance
• perform a dilated pupil examination to see the inside of the eye with an ophthalmoscope to check for drusen (tiny yellow deposits on the retina which are the most common early signs of AMD)
• ask the patient to look at an Amsler grid with a pattern of straight horizontal and vertical lines. To the person with AMD, the lines appear wavy, distorted or missing or a black spot may appear in the center of the grid.
• perform a fluorescein angiography. During this test, a dye is injected into the arm and quickly travels throughout the blood system. Once the dye reaches the blood vessels in the back of the eye, photographs are taken of the eye. The dye allows the ophthalmologist to detect blood vessels that are abnormal and leaking dye.

What are the current treatment options for macular degeneration?

Currently, treatments for macular degeneration are rapidly advancing and changing approximately every three months. It is anticipated that for the next three to five years, the treatment will be changing all the time. Various treatments are currently available, but most of these treatments are directed at the early stage of wet AMD. Regardless of the treatment therapy followed, patients with advanced dry macular degeneration should check the vision in each eye, one at a time, at least once a day. By staring at the central point on an amsler grid , patients can help monitor their vision regularly and can detect distortions in vision. These distortions represent the earliest stages of wet macular degeneration.

One treatment for wet AMD is thermal laser photocoagulation of the abnormal blood vessels. Only 15 percent of patients with wet AMD are eligible for this therapy. Among those treated, the blood vessels continue to grow in about 50 percent of the cases. Overall, this means that laser photocoagulation is really only helpful in about 7-8 percent of patients with wet AMD. When successfully treated, wet macular degeneration is converted back to dry macular degeneration. Over time, there will be continued vision loss, but the outcome is far better than the outcome if the wet AMD was untreated. Laser photocoagulation isn't useful for most cases of wet AMD because the blood vessels are under the center of the macula. If these blood vessels are treated with the hot laser, the center of the macula would be burned and immediate vision loss would result. This has limited the usefulness of laser photocoagulation.

The results of the photodynamic therapy trials are a breakthrough for patients with AMD. Until now, there was no treatment that would slow the progression of this disease for the vast majority of patients with wet AMD, and some patients (10-15%) may even get visual improvement. It is estimated that more than one million people in the United States currently have wet AMD, and 200,000 new cases will be diagnosed this year. This treatment will have a tremendous impact, even though most patients with wet AMD still will not benefit from this therapy. Only about 25% of the wet AMD patients with blood vessels growing under the center of their vision will qualify for photodynamic therapy.

Visudyne therapy is based on the new platform of technology, photodynamic therapy. It entails a two-step approach designed to affect the abnormal blood vessels in wet AMD:

• First, a photosensitizing agent, a new type of drug, is injected into a vein in the arm. The drug circulates throughout the body's blood vessels, including the abnormal vessels under the macula.
• Next, a "non-burning" laser is shined on the abnormal blood vessels, activating the drug.

Step 1
Step 2

The activated drug then selectively affects the abnormal blood vessels without damaging the surrounding retinal tissue. In some cases the therapy stops growth of the abnormal blood vessels and halts the corresponding vision loss.

Despite all these advances, we still do not have effective therapies for the vast majority of patients with dry or wet AMD. For this reason, the best option for many of our patients is to receive low vision training. Whether it is vision loss for conditions such as AMD, glaucoma or diabetes, low vision aids help patients perform normal activities of daily living and lead independent lives. To help facilitate this training,

What is a macular hole?

As people age, the vitreous gel in the eye shrinks and pulls away from the retina. Usually this occurs without consequence, however, in some cases where the vitreous is attached to the macula, it can result in the formation of a macular hole. Fluid may leak under the edges of the hole, causing a microscopic retinal detachment, which results in blurring and distortion of vision.

What are the symptoms of a macular hole?

A macular hole can cause blurred or distorted vision. A hole that goes all the way through the macula can result in significant loss of central vision.

How is a macular hole diagnosed?

An ophthalmologists who suspects a macular hole may:

• perform a visual acuity test to measure vision at a distance
• perform a dilated pupil examination to see the inside of the eye with an ophthalmoscope
• perform a fluorescein angiography. During this test, a dye is injected into the arm and quickly travels throughout the blood system. Once the dye reaches the blood vessels under the retina, a color photograph is taken of the eye. The dye allows the ophthalmologist to detect blood vessels that are leaking dye.

What are retinal detachments and retinal tears?

The retina lies flat against the inside, back wall of the eye. A retinal detachment occurs when the retina is lifted or pulled from its normal position. This can happen as a result of normal retraction of the vitreous which can tear the retina and allow fluid to seep beneath it causing a separation; a tumor; complications from other diseases; a severe blow to the head or eye and occasionally it is hereditary.

A retinal tear occurs when the vitreous shrinks, pulling a tear, or rip, in the retina. Most tears occur on the peripheral retina and have little effect on vision. However they may lead to an accumulation of fluid under the retina, which results in retinal detachment and significant vision loss.

What are the symptoms of retinal detachments?

Retinal detachment may be gradual or sudden, but it is usually accompanied by a dramatic loss of vision --- partial or complete. Many people see flashes of light, floaters or the appearance of a dark or gray curtain moving across the field of vision or a wavy or watery effect in their vision. These symptoms do no always mean the retina has detached, however, if they are present, an ophthalmologist should be consulted immediately as a detachment can cause permanent vision loss.

How are retinal detachments and tears diagnosed?

An ophthalmologist can diagnose retinal detachments and tears during a dilated pupil examination. Some can also be found during routine eye exams.

What is the treatment for retinal detachments and tears?

Retinal detachments are almost always repaired surgically. Treatment depends on the cause and extent of the retinal detachment. Most retinal tears are treated with cryo-therapy (use of a freezing probe) or laser therapy. Treatment usually prevents retinal detachment.

Alternatives include pneumatic retinopexy, scleral buckling procedure or vitrectomy with gas or silicone oil tamponade.

Pneumatic retinopexy involves injecting a gas bubble into the vitreous space. The bubble pushes the retinal tear against the back of the eye.

Scleral buckle is a tiny, flexible band that is placed around the outside of the eyeball to gently push the wall of the eye against the detached retina.

Vitrectomy is the surgical extraction of the vitreous humor and simultaneous replacement with a clear sterile solution or a dissolvable gas bubble.

Early treatment usually improves the vision of most patients with retinal detachment. Some will need more than one procedure to repair the damage, but some detachments cannot be repaired.

What is uveitis?

Uveitis is an inflammation of the uvea, the layer of the eye that lies between the retina and the sclera. The uvea contains many of the blood vessels which nourish the eye. Inflammation of the uvea can affect the cornea, the retina, the sclera, and other vital parts of the eye. Since the uvea borders many important parts of the eye, inflammation of this layer may be sight-threatening and more serious than the more common inflammations of the outside layers of the eye.

Uveitis has many different causes. It may develop following eye surgery or trauma. It may result from a virus (such as shingles, mumps, or herpes), a fungus (such as histoplasmosis), or a parasite (such as toxoplasmosis). In most cases, the cause remains unknown.

Uveitis can also be related to autoimmunity or come as a consequence of injury to the eye. Inflammation in one eye can result from a severe injury to the opposite eye (sympathetic uveitis).

What are the symptoms of uveitis?

Inflammation from uveitis may involve any of the following: the iris, the ciliary body or the choroid, therefore symptoms may be present in any of these structures. The symptoms include pain, blurred vision, redness, floaters or sensitivity to light.

How is uveitis diagnosed?

Uveitis is diagnosed through a routine eye examination using an ophthalmoscope.

What is the treatment for uveitis?

Uveitis may be treated with eyedrops, injections or oral medication. The most severe cases may require chemotherapy to suppress the immune system.

What is CMV retinitis?

Cytomegalovirus infection of the retina, known as CMV retinitis, occurs primarily in patients with acquired immunodeficiency syndrome, AIDS, though it can occur in patients with other immunosuppressive diseases. This serious infection is found in 20 - 30% of people with AIDS. Most CMV infections occur in people whose T-cell counts is dangerously low, usually under 40.

What are the symptoms of CMV retinitis?

People with CMV retinitis generally do not experience any pain but may develop floating spots in their vision, flashing lights, blind spots, blurred vision or loss of central or peripheral vision. CMV can also cause the retina to separate from the back of the eye. The disease generally starts in one eye, but often will involve both eyes. If untreated the disease can bring about retinal detachment and cause blindness in as little as two to six months.

How is CMV retinitis diagnosed?

Occasionally, the condition is detected during a routine exam when the infectious process is early and located in the peripheral retina.

What is the treatment for CMV retinitis?

Patients diagnosed with CMV retinitis are generally treated with antiviral medications, gancyclovir, foscarnet or cidofovir which can slow the progression of the disease but cannot cure it. The medications are administered intravenously, in pill form or via pellet implanted directly into the vitreous in the eye. The pill and intravenous medications allow for immediate infusion while the pellet allows for a slow, timed release of the medicine for approximately 5 to 8 months.

Nearly 100% of patients will eventually have a relapse of CMV retinitis, despite the best attempts at control.

What is retinopathy of prematurity?

Retinopathy of prematurity (ROP) is the leading cause of childhood blindness in developed countries.

Premature or low birth weight babies often need to receive oxygen until their immature lungs develop. Today, physicians know that exposure to high levels of oxygen over extended periods of time can trigger the disease in infants, causing the retina's tiny developing blood vessels to grow wildly and produce scars. In some children, the retina is able to recover and damage is moderate. However, in severe cases, there is retinal detachment and, ultimately, blindness.

What is retinoblastoma?

Retinoblastoma (RB) is a rare form of cancer affecting the light-sensitive retinal cells that enable sight. Although the disease is very rare, it is the most common ocular malignancy in children and the third most common cancer to affect children --- occurring in one out of every 15,000 births. In the United States, 250 to 350 new cases are diagnosed each year --- 90 percent of which occur in children under five years of age.

There are two types; one is hereditary and affects both eyes (occurs in 10% of cases) and the other type is non-hereditary and affects only one eye, carrying no increased risk of a second tumor. Although the cancer is genetically determined, only 6 percent of newly diagnosed RB patients are found to have a positive family history of the disease. Forty percent of all children have a lifelong cancer risk from abnormality in the RB gene located in chromosome 13. In all cases, genetic counseling is important for children with a germ-line mutation.

What are the current treatment options for retinoblastoma?

Early detection of RB greatly enhances the possibility of a cure and the preservation of the greatest amount of vision, though it can lead to vision loss of one or both eyes. The treatment of RB depends on the size and location of the tumor and whether one or both eyes are involved. With earlier detection and improved treatments, the prognosis for vision and life for RB patients has improved significantly in the past twenty years. However, because the disease is so rare, many pediatricians and primary care providers may not recognize the early signs, and parents rarely notice the subtle changes that may identify a tumor in their child's eyes. Left untreated, RB tumor nodules grow rapidly, expanding to fill the eye and extending along the optic nerve to the brain, ultimately causing death.

What is retinitis pigmentosa?

Retinitis pigmentosa (RP) is a group of diseases which tend to run in families that cause progressive degeneration of the retina in both eyes. It progresses from night blindness to loss of the peripheral visual field. The signs of the disease usually present in youth or young adulthood, but can occur at any age. Over many years, RP then progresses to tunnel vision and finally blindness.

What are the symptoms of retinitis pigmentosa?

The symptoms of RP vary and can include night blindness in early stages of the disease. Night blindness refers to an inability to adjust vision to the darkness or a very slow adjustment. During later stages, the next symptom to appear is a gradual loss of peripheral or side vision so that the person can only see through a small area of the eye and only straight ahead, this is also referred to as tunnel vision.

What are flashes and floaters?

Flashes are a brief perception of light in the field of vision and floaters are bits of optical debris usually in the vitreous that are interpreted as threats or small spots or circles.

As a person ages, the vitreous thins and may separate from the retina, causing a posterior vitreous detachment, a common, typically harmless condition. When posterior vitreous detachment occurs, the detached vitreous can pull on the retina accompanied by flashes of light or tiny bits of vitreous that cast shadows on the retina creating floaters.

What are the symptoms of floaters and flashes?

Floaters can appear to be black spots or small circles, cob webs that may move or remain in one place. Flashes take on the appearance of bright flashes of light. More serious symptoms includes a sudden decrease of vision accompanied by floaters and flashes; a curtain that obstructs the field of vision; or a sudden increase in floaters.

How are floaters and flashes diagnosed?

Your ophthalmologist will exam your retina through dilated pupils with an ophthalmoscope.

What are the current treatment options for floaters and flashes?

In most cases of posterior vitreous detachment, surgery is not recommended and the patient can learn to ignore the floaters and they usually become less bothersome over several weeks. In more severe cases, vitrectomy may be considered only if vision is significantly compromised.