What are ocular allergies?

What Is allergic conjunctivitis?

Is there a treatment for ocular allergies?

What are topical decongestants?

What are topical antihistamines?

Are there any helpful strategies to relieve ocular allergies?

What are steroids?

Is glaucoma hereditary?

What is the difference between ocular hypertension and glaucoma?

What is narrow angle glaucoma? Is it more, or less, serious than other types of the disease? What is the prognosis for the average patient? What are the symptoms?

Can the ailments glaucoma and cataracts coexist?

Is there any bleeding associated with glaucoma?

I would like some information on any preventive steps for the early treatment of glaucoma, as well as information on cause and treatment of any kind.

Could you explain the range of numbers for glaucoma? When is the number in the range of high-risk glaucoma?

Discuss risks and benefits of glaucoma surgery vs. eye drops alone.

I’ve heard that marijuana, which is currently an illegal substance, is helpful in the treatment of glaucoma. Is this true? If so, why can’t it be prescribed?

Where is some of the most advanced work being done on glaucoma? Who might be a good source of information about support groups?

How often should a person suffering from glaucoma have their intraocular pressure (IOP) measured and their visual field tested to prevent risk of further damage?

When a person suffering from glaucoma is having blurred vision in certain instances, is it a sign of further damage? What can one do to avoid risk of further damage?

Do reading, handwork and other such hobbies increase damage to the eyesight of persons with glaucoma?

Can the two types of topical medication — the type increasing outflow of aqueous and the type reducing amount of aqueous produced — be used simultaneously?

Besides medication, what precautions should a person suffering from glaucoma take to prevent risks of vision damage, for example, when in bright/dim light or when using tinted/untinted spectacles?

If a person suffering from glaucoma and high intra ocular pressure suffers also from breathlessness, and as a result cannot use timoptic, etc., is it enough to control only the outflow of aqueous?

Is cryotherapy a method of treatment that is used often for glaucoma?

My doctor says that I have pigmentary dispersion. Does that mean I will get glaucoma?

Can you explain the range of intraocular pressure (IOP) numbers for glaucoma? When is the number in the range for high-risk glaucoma?

Why are there so many prescriptions that warn against their use if you have glaucoma? Should I be concerned?

Is there a connection between tamoxifen and cataracts?

Please outline the surgical options presently available to treat cataracts. Also, what is the newest procedure for removing cataracts?

Does the surgeon ever use a stitch to reduce the degree of astigmatism which may follow this procedure? I am assuming no stitch is required to close the incision.

What effect does cataract surgery have on people with increased risk of retinal detachment (genetic or otherwise)? Are there any specific things the doctor or patient should be aware of? What are the long-term effects of living without a lens (for example, in a severely myopic person where vision is close to normal without it)? My interest in these questions is in relation to Stickler Syndrome.

What is the best lens for implanting? Acrylic or silicone? What problems are associated with each?

What is the AcrySof® ReSTOR® lens?

The mother of a friend of mine has diabetes, so should she be concerned with possible eye-related problems? If so, which?

Why is it important that a child receive a dilated examination once a year if the child is diagnosed with juvenile diabetes? Approximately how many children under age with juvenile diabetes are treated for eye- related problems?

Is there a cause and effect relationship between adult onset diabetes and macular degeneration? Will careful control of the diabetes lessen the progress of macular degeneration?

I have had laser treatments for diabetic retinopathy. One eye still has neovascularization. What additional treatments are there?

Is it possible to be suffering from diabetic retinopathy but not have any other outward symptoms of diabetes? Would this disease be easily diagnosed when the patient has undergone intense eye exams or can this be easily mistaken for other eye diseases? My daughter has been diagnosed with a “cone-rod dystrophy.” Can this be mistaken for diabetic retinopathy?

Is there a cure for partial sight loss as a consequence of diabetic retinopathy ?

What diet would you recommend for people having diabetic retinopathy (zinc rich, etc.)?

Can diabetic retinopathy be counter-arrested by surgery, e.g. replacing part of the retina/macula?

Can you tell me if the damage done from diabetic retinopathy can be healed or reconstructed so the vision loss is not permanent?

I am interested in learning more about diabetic retinopathy. Could you tell me how many Americans each year are diagnosed with diabetic retinopathy? Also, how many laser surgeries for this disease are performed each year and if possible what percentage of these surgeries result in full restoration of one’s vision. Are there any breakthroughs in diagnosis or treatment that I should know about?

Do Any One of These Conditions Describe Your Eyesight?

It may sound like Greek, but the words myopia , hyperopia , astigmatism , and presbyopia describe vision problems that afflict countless millions of people of all ages.

All of these terms come together to describe what are known as “refractive errors.” Refraction refers to the ability of the eye to focus light. The shape of the cornea, the strength of the lens and of the eye, and the length of the eyeball determine how clearly you see. If even one of these factors is not coordinating properly with the others, light will not focus correctly and your vision will not be clear.

Myopia—commonly called nearsightedness—is the most common refractive error. People with myopia can see objects closer to them, but have difficulty focusing on distant objects. The condition is caused by a cornea that has more curvature than normal, or an eyeball that is too long. In either case, light is focused at a point in front of the retina, causing a blurred image. About one in four American adults are myopic. The condition usually begins in childhood, and often stabilizes in the late teen years or twenties.

Hyperopia is farsightedness, the opposite of myopia. For some people with hyperopia, objects at a distance are clear, while objects up close are blurry with uncorrected vision. This is caused by a flatter-than-normal cornea, or an eyeball that is too short—causing light to focus on a position behind the retina.

Astigmatism, or ovalness of the cornea, is another refractive problem. With this condition, there is typically a distortion of the cornea that tilts or bends the image due to an unequal bending of light as it attempts to focus. People with a high degree of astigmatism have difficulty focusing properly at any distance, and experience a “ghosting” or “doubling” effect with the images they view. Nearsighted and farsighted people may also have some degree of astigmatism.

Finally, presbyopia is a very common condition that is simply part of the normal aging process. Presbyopia develops as the lens of the eye loses flexibility, typically between the ages of 40 and 50. Those who are farsighted or nearsighted find they need to wear bifocals, and those with normal vision will need to wear reading glasses. If patients with presbyopia have corrective laser surgery for either myopia or hyperopia, they will probably need to wear corrective lenses for reading.

Through technological advances in recent years, ophthalmologists and researchers have devised increasingly effective ways to overcome or minimize most of these conditions - - most notably, the development of the LASIK surgical procedure.

refractive questions       (Back to top of page >>)

What are floaters?

You may sometimes see small specks or clouds moving in your field of vision. They are called floaters. You can often see them when looking at a plain background, like a blank wall or blue sky. Floaters are actually tiny clumps of gel or cells inside the vitreous, the clear jelly-like fluid that fills the inside of your eye.

While these objects look like they are in front of your eye, they are actually floating inside. What you see are the shadows they cast on the retina, the nerve layer at the back of the eye that senses light and allows you to see. Floaters can have different shapes: little dots, circles, lines, clouds or cobwebs.

What causes floaters?

When people reach middle age, the vitreous gel may start to thicken or shrink, forming clumps or strands inside the eye. The vitreous gel pulls away from the back wall of the eye, causing a posterior vitreous detachment. It is a common cause of floaters. Posterior vitreous detachment is more common for people who:

• Are nearsighted
  
• Have undergone cataract operations
  
• Have had YAG laser surgery of the eye
  
• Have had inflammation inside the eye
  

The appearance of floaters may be alarming, especially if they develop suddenly. You should see an ophthalmologist (a medical eye physician) right away if you suddenly develop new floaters.

Are floaters ever serious?

The retina can tear if the shrinking vitreous gel pulls away from the wall of the eye. This sometimes causes a small amount of bleeding in the eye that may appear as new floaters. A torn retina is always a serious problem, since it can lead to a retinal detachment. You should see your ophthalmologist as soon as possible if:

• Even one new floater appears suddenly
  
• You see sudden flashes of light
  

If you notice other symptoms, like the loss of side vision, you should return to your ophthalmologist.

What can be done about floaters?

Floaters can get in the way of clear vision, which may be quite annoying, especially if you are trying to read. You can try moving your eyes, looking up and then down to move the floaters out of the way. While some floaters may remain in your vision, many of them will fade over time and become less bothersome. Even if you have had some floaters for years, you should have an eye examination immediately if you notice new ones.

What causes flashing lights?

You may have experienced this same sensation if you have ever been hit in the eye and seen “stars.” When the vitreous shrinks, it tugs on the retina, creating a sensation of flashing lights.The flashes of light can appear off and on for several weeks or months. As we grow older, it is more common to experience flashes. If you notice the sudden appearance of light flashes, you should visit your ophthalmologist immediately to see if the retina has been torn.

What are migraines?

Some people experience flashes of light that appear as jagged lines or “heat waves” in both eyes, often lasting 10-20 minutes. These types of flashes are usually caused by a spasm of blood vessels in the brain, which is called migraine. If a headache follows the flashes, it is called a migraine headache. However, jagged lines or “heat waves” can occur without a headache. In this case, the light flashes are called ophthalmic or ocular migraine, which is a migraine without headache.

How are your eyes examined?

When an ophthalmologist examines your eyes, your pupils will be dilated with eye drops. During this painless examination, your ophthalmologist will carefully observe your retina and vitreous. Because your eyes have been dilated, you may need to make arrangements for someone to drive you home afterwards. Floaters and flashes of light become more common as we grow older. While not all floaters and flashes are serious, you should always have a medical eye examination by an ophthalmologist to make sure there has been no damage to your retina.

© Copyright American Academy of Ophthalmology

retina questions       (Back to top of page >>)

The eyes are one of the most sensitive and vulnerable organs in the body. Airborne allergens and other particles can land directly on the surface of the eye, causing irritation and redness. Although tears constantly wash the eyes, they can’t always keep out allergens like pollen or pet dander. Because of this, allergies that flare up in the eyes, also known as ocular allergies, are common.

What are ocular allergies?

Eye allergies are no different than allergies that affect your sinuses, nose or lungs. When an allergen comes in contact with your eyes, your body releases histamine - a chemical produced in reaction to a substance that the immune system can’t tolerate. Special cells called mast cells make histamine. These cells are present throughout the body but are highly concentrated in the eyes.

Location of allergy symptoms depends somewhat on where the allergen has come into contact with your body. Ocular allergens tend to be airborne (as are most other allergens). The most frequent allergic triggers include:

• Pollen
  
• Pet hair or dander
  
• Dust
  
• Some medicines
  

There also are some triggers that irritate the eyes but are not true allergies, such as:

• Cigarette smoke
  
• Perfume
  
• Diesel Exhaust
  

What Is allergic conjunctivitis?

Conjunctivitis, also known as “pink eye,” is an inflammation of the conjunctiva (the membrane lining the surface of the eye and under the eyelids) and can be caused by allergies or infections. Allergic conjunctivitis and conjunctivitis caused by an infection can be hard to distinguish. Both have similar symptoms, such as redness, itching and swelling in the eye area. However, when conjunctivitis is caused by allergies, both eyes are usually affected. Viral or bacterial conjunctivitis can affect either a single eye or both eyes. It is important to pinpoint whether someone has conjunctivitis because of allergies or infection since each condition has a different treatment.

Common symptoms of allergic conjunctivitis are:

• Redness and itching under the eyelid
  
• Excessive watering
  
• Swelling of the eyeball
  

Common symptoms of conjunctivitis associated with infection are:

• Feeling that eyelids are glued shut upon waking
  
• Sensitivity to light
  
• Pus on the surface of the eye
  
• Burning sensation
  

Is there a treatment for ocular allergies?

If you have ocular allergies or any other kind of allergic disease, the most effective treatment is prevention: try to avoid the allergens that trigger symptoms. For many, this is easier said than done, especially if your triggers are airborne, such as pollen.

When ocular allergies can’t be controlled with avoidance, there are several medications that may help relieve symptoms. Most of these treatments come in a topical form - such as eye drops or an ointment.

Eye drops, also called “artificial tears,” can help in two ways: (1) by physically washing away allergens; and (2) by moistening the eye, which can become dry and red when irritated. Eye drops that contain medications to help reduce allergy symptoms also are available.

What are topical decongestants?

Some eye drops contain topical decongestants that constrict small blood vessels and help reduce eye redness. These eye drops are available without a prescription. If you use eye drops with topical decongestants, be careful not to use them for prolonged periods. Overuse of topical decongestants can lead to increased swelling and redness that can last even after you stop using the drops. This is known as a “rebound effect.”

Topical decongestants, or any kind of eye drop containing chemicals that narrow blood vessels (called vasoconstrictors), shouldn’t be used if you have glaucoma. Glaucoma is damage to the eye that results from increased pressure in the eyeball. Vasoconstrictors can worsen this condition.

What are topical antihistamines?

Eye drops containing antihistamines can reduce redness and swelling in the eye. Antihistamines block the effects of the chemical histamine, which is responsible for allergic symptoms like swelling, redness and itching. Mild antihistamine eye drops are available over the counter, but stronger ones are available by prescription.

Are there any helpful strategies to relieve ocular allergies?

Chilling any topical medications can help relieve redness and itching of the eyes. In addition, using cold compresses can help reduce some of the discomfort associated with conjunctivitis. A washcloth soaked in cold water works well.

Oral nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen-based medications, also can help reduce inflammation and symptoms like swelling in some patients.

What are steroids?

When topically administered medications like antihistamines and vasoconstrictors fail to help alleviate conjunctivitis symptoms, your doctor may prescribe topical steroids. Steroid eye drops can help control chronic and acute cases of conjunctivitis but should only be used as prescribed by your doctor. Steroids applied directly to the eye can cause a sharp increase in ocular pressure that can result in significant eye damage or glaucoma. Prolonged use of topical steroids in the eyes also can lead to cataracts. Cataracts form when the lens of the eye gradually becomes opaque, causing decreased visual acuity.

Because steroids can promote the growth of some viruses, your doctor will want to rule out viral conjunctivitis as the cause of your eye problems before prescribing topical steroids.

© Copyright American Academy of Ophthalmology

allergy questions       (Back to top of page >>)

Is glaucoma hereditary?

A family history of glaucoma does increase the incidence of glaucoma in family members and a routine ophthalmologic examination should be scheduled.

What is the difference between ocular hypertension and glaucoma?

Ocular hypertension describes the condition where the intraocular pressure is above normal. Glaucoma describes the condition where there is damage to the eye associated with elevated intraocular pressure.

What is narrow angle glaucoma? Is it more, or less, serious than other types of the disease? What is the prognosis for the average patient? What are the symptoms?

Narrow angle glaucoma is a type of glaucoma where the aqueous, the fluid produced normally in the eye, cannot reach the trabecular meshwork, which is the site where most of this fluid normally exits the eye. The prognosis is good for patients in whom a timely diagnosis is made and appropriate laser treatment performed. With narrow angle glaucoma, an acute glaucoma attack can occur which is often associated with pain, blurred vision, and a red eye. However, some patients have a chronic form of this disease and have no symptoms.

Can the ailments glaucoma and cataracts coexist?

Glaucoma and cataracts often appear together, as they are commonly present in older patients. There are many new surgical techniques which can help patients with both of these conditions.

Is there any bleeding associated with glaucoma?

Glaucoma is a disease not typically associated with bleeding. However, there are cases where bleeding can be a cause of elevated intraocular pressure although these are infrequent.

I would like some information on possible preventive steps for glaucoma.

The best measure for preventing damage from glaucoma is a timely, complete ophthalmic examination. There are many different potential causes but your best investment for protecting your vision is to have a complete eye examination performed by an ophthalmologist.

Could you explain the range of numbers for glaucoma? When is the number in the range of high-risk glaucoma?

Statistically, most patients will have intraocular pressure less than 22 mm Hg. However, glaucoma can occur with pressures lower than this and also some patients’ eyes can tolerate pressures considerably higher than this. The only way we can determine an exact target pressure is after a complete ocular examination by an ophthalmologist and appropriate follow-up.

Discuss the risks and benefits of glaucoma surgery vs. eye drops alone.

This is a complicated question and is affected by the specifics of a given patient and their tolerance of medication. I would urge you to discuss this with your ophthalmologist who can review it with particular regard to your specific ocular condition.

I’ve heard that marijuana, which is currently an illegal substance, is helpful in treatment of glaucoma. Is this true? If so, why can’t it be prescribed?

There are many substances that are being evaluated for their effectiveness in the treatment of glaucoma. Once their efficacy and safety have been shown through appropriate clinical trials we can use them in routine treatment of our patients. Marijuana is not as effective as any currently available glaucoma medication.

Where is some of the most advanced work being done on glaucoma? Who might be a good source of information about support groups?

There are many centers where active research is being performed in the glaucoma field. The Glaucoma Research Foundation in San Francisco may be able to give you the names of the research centers in your area. They may also have additional information on support groups. You can contact them at (415) 986-3162. You may also visit their website at: http://www.glaucoma.org/.

How often should a person suffering from glaucoma have their intraocular pressure (IOP) measured and their visual field tested to prevent risk of further damage?

The required frequency of visual field testing and IOP testing depends on the disease state in a particular patient; this is something you should discuss specifically with your ophthalmologist.

When a person suffering from glaucoma is having blurred vision, is it a sign of further damage? What can one do to avoid risk of further damage?

Unfortunately, with glaucoma, typically there are no symptoms until extensive damage has occurred. For this reason, it is important to have routine eye examinations by an ophthalmologist.

Do reading, handwork and other such hobbies increase damage to the eyesight of persons with glaucoma?

No. Using your eyes does not damage them, even if you have glaucoma.

Can the two types of topical medication — the type increasing outflow of aqueous and the type reducing amount of aqueous produced — be used simultaneously?

Yes, both types of topical medication can be used simultaneously.

Besides medication, what precautions should a person suffering from glaucoma take to prevent risks of vision damage? For example, is reading in bright/dim light or using tinted/untinted spectacles harmful?

Most routine activities will not negatively influence your glaucoma.

If a person suffering from glaucoma suffers also from shortness of breath, does this influence the type of glaucoma medication that is appropriate?

There are many types of medications available to treat glaucoma. You need to speak with your ophthalmologist who can then review the other alternatives available to you. In patients with breathing abnormalities, a class of medication often used to treat glaucoma, the beta-blockers, should not but used. Beyond medications, laser and additional surgeries are usually an option.

Is cryotherapy a method of treatment that is used often for glaucoma?

Cryotherapy is not a method that is often used to treat glaucoma. It is used to treat some other disorders, such as retinopathy of prematurity.

My doctor says that I have pigmentary dispersion. Does that mean I will get glaucoma?

Not all people who have pigmentary dispersion develop glaucoma. Pigmentary dispersion is a disorder in which some pigment granules leak out of the iris. The granules may clog the trabecular meshwork, preventing the normal aqueous outflow. This in turn causes an increase in intraocular pressure, which may lead to glaucoma.

It is impossible to know for sure which individuals with pigmentary dispersion will develop glaucoma, so it is particularly important for you to have regular medical eye exams.

Can you explain the range of intraocular pressure (IOP) numbers for glaucoma? When is the number in the range for high-risk glaucoma?

IOP responses based on statistical studies have been examined, and an average standard deviation of IOP has been established. Pressures below 22 mm Hg are considered within “normal” range. However, some people with pressures consistently lower than 22 mm Hg have gone on to develop optic nerve damage of glaucoma, and some with consistently higher pressures never have optic nerve damage. The appropriate target IOP for a particular patient, or, specifically, a particular eye, is dependent on how that eye’s optic nerve is tolerating the associated IOP.

Why are there so many prescriptions that warn against their use if you have glaucoma? Should I be concerned?

Certain medications are not to be used in a particular type of glaucoma called “narrow angle” glaucoma. This type of glaucoma is relatively rare. Individuals with the much more common “open-angle” glaucoma do not have to be as concerned about taking such medications. We suggest all patients with glaucoma consult with their doctor before taking any type of new medication.

Disclaimer: The responses provided through this service are not intended to replace consultation with an ophthalmologist. This question and answer service is intended for general educational purposes only and the responses represent the approach of the responding physician given the facts presented, not necessarily the only or best method or procedure in every case. Please refer to the Academy’s full disclaimer.

© Copyright American Academy of Ophthalmology

glaucoma questions       (Back to top of page >>)

Is there a connection between tamoxifen and cataracts? I have heard it debated — pro and con! What’s your opinion?

The Physician’s Desk Reference states that visual disturbances including corneal changes, cataracts, and retinopathy have been reported in patients receiving tamoxifen. This does not necessarily mean that tamoxifen caused these changes, however. An association or lack of association between tamoxifen and cataracts is difficult to prove or disprove. Nearly all people develop cataracts to some extent as they age, and these cataracts get progressively worse as time passes. The majority of patients on tamoxifen are older women, and already have cataracts to some degree just because of their age. Therefore cataracts are seen in many people who are taking tamoxifen, and since these people get older while taking the drug, their cataracts get worse due to their advancing age. It is very difficult to know whether tamoxifen plays a role in this worsening. There is not very much literature on the subject. Tamoxifen does appear to cause cataracts in rats, and there are possible biochemical mechanisms by which it could cause cataracts. In humans, however, a cause and effect relationship has not been convincingly demonstrated.

Doctors locally advertise one stitch or no stitch, laser, sound waves, etc. Please outline the surgical options presently available. Also, what is the newest procedure for removing cataracts?

Carolina Ophthalmology Associates, PA uses either no stitch or one-stitch surgery. Nearly all cataracts today are removed by extracapsular surgery, in which the posterior capsule of the natural lens is left in place to support the plastic replacement lens which is implanted at the time of surgery.

There are two types of extracapsular surgery.

1. In planned extracapsular surgery the nucleus of the lens, which is too hard to simply remove by aspiration, is taken out in one piece, and the softer parts of the lens are then aspirated.
   
2. In phacoemulsification the hard nucleus is broken up by ultrasonic fragmentation (using sound waves) within the eye, and can then be aspirated. This allows a smaller incision to be used. Phacoemulsification has gained in popularity in recent years, and is now the most common form of cataract removal in the United States. This procedure has been used for approximately 25 years, although recent advances and refinements have made it safer and more effective than previously. Although not new, this would still be the “newest” procedure for cataract removal.
   

Both “one-stitch” and “no-stitch” surgery are just variants of phacoemulsification. The incision used in the surgery may be placed in one of several locations and the architecture of the incision may vary as well. The same incision may be “no-stitch” if the incision is watertight following surgery, or “one-stitch” if it is not, and requires a stitch to make it so.

The incision size for phacoemulsification is less than 3.0 millimeters in width. If a lens implant which can be folded is used following removal of the cataract, this incision may not have to be enlarged. If a lens is used which cannot be folded, the incision must be enlarged to 5.0 or 5.5 mm. A larger incision is more likely to need a stitch. In addition, some surgeons simply prefer the safety of having the incision sutured, even if the incision is already watertight. The best procedure for a patient is usually the one with which his or her ophthalmologist feels the most comfortable, since these variations of cataract surgery are all quite effective.

Despite some public misconception, laser is not an option for removing cataracts at this time. There are laser devices for cataract removal under investigation, but none are approved by the Food and Drug Administration. Even the experimental devices are quite different from what one might imagine for use in a laser cataract surgery. In these devices a laser is used to break up the nucleus of the cataract into pieces small enough that they can be aspirated from the eye, in the same manner that sound waves are used in phacoemulsification. Thus, an incision still needs to be made, and the lens material removed from the eye. The proverbial “ZAP” of the laser and the cataract is gone while the patient sits in the chair will never happen, since a very small incision will always be needed to physically remove the cataractous lens material.

The YAG laser is used following cataract surgery if the posterior capsule of the lens, which supports the lens implant, becomes cloudy. This indeed is a procedure in which the patient sits in the chair and the vision is quickly cleared by the laser. It is not used to remove the cataract itself, however.

Does the surgeon ever use a stitch to reduce the degree of astigmatism which may follow this procedure? I am assuming no stitch is required to close the incision.

When a cataract is removed, one or more stitches can be used to close the incision, and these can indeed modify astigmatism. The most commonly used suture in cataract surgery is nylon. Although nylon is very inert, the body does eventually manage to degrade it, and any modification of the astigmatism would disappear at that time. This usually happens by a year following surgery. A more effective method of altering astigmatism is to place the incision in a location in which the effect of the incision itself reduces the astigmatism, and this is commonly done. Another way to reduce higher amounts of astigmatism is to make extra partial-thickness incisions in the cornea, either at the time of the surgery, or at a later date. This procedure is called astigmatic keratotomy.

What effect does cataract surgery have on people with increased risk of retinal detachment (genetic or otherwise)? Are there any specific things the doctor or patient should be aware of? What are the long-term effects of living without a lens (for example, in a severely myopic person where vision is close to normal without it)? My interest in these questions is in relation to Stickler Syndrome.

Cataract surgery has long been known to increase the risk of retinal detachment. This risk is less now with extracapsular surgery, in which the posterior capsule of the lens is left in place, than it was when the entire lens was removed. This type of surgery is by far the predominant form in the United States at this time.

People at increased risk of retinal detachment include those who are very nearsighted (myopic) and those who have any of the vitreoretinal syndromes, such as Stickler Syndrome or Wagner’s disease. Since these people are at a much increased risk of detachment anyway (greater than 50% for Stickler Syndrome), addition of another risk factor increases the likelihood even more. These people need to have regular retinal examinations and seek medical help immediately if they have any disturbing symptoms, such as new floaters, lightning flashes, or shadows and curtains covering the vision.

What is the best lens for implanting? Acrylic or silicone? What problems are associated with each?

There are three materials presently used for intraocular lenses, polymethylmethacrylate (PMMA), silicone, and acrylic, with other materials under development. None of these materials is clearly superior to the others. Each has advantages and disadvantages. PMMA has been used the longest by far, and thus has the best safety record. It must be implanted through a larger incision than the other materials. Silicone and acrylic can each be placed through a smaller incision than PMMA. Acrylic affords a very controlled unfolding of the lens, but silicone can go through a smaller incision than acrylic.

Today’s intraocular lenses are very safe and effective. Most problems after surgery are related to the eye’s reaction to the surgery itself, to problems arising during the surgery, or to positioning of the lens implant, rather than difficulty with the design of the lens or the material of which it is made. All of the available lens materials perform admirably.

Disclaimer: The responses provided through this service are not intended to replace consultation with an ophthalmologist. This question and answer service is intended for general educational purposes only and the responses represent the approach of the responding physician given the facts presented, not necessarily the only or best method or procedure in every case. Please refer to the Academy’s full disclaimer.

What is the AcrySof® ReSTOR® lens?

Previous intraocular lens technology provided only one focal point — distance — leaving patients dependent upon reading glasses or bifocals. The AcrySof® ReSTOR® lens design results in highly predictable visual outcomes so you can now read the words on prescription bottles, magazines, newspapers and computer screens, without reading glasses or bifocals, while still clearly seeing objects at a distance. It has the ability to consistently offer improved vision at a range of distances: near through distance.

© Copyright American Academy of Ophthalmology

cataract questions       (Back to top of page >>)

The mother of a friend of mine has diabetes, so should she be concerned with possible eye-related problems? If so, which?

You are correct in suggesting your friend’s mother have an ophthalmologic examination because she is at a higher risk for problems due to her diabetes.

Why is it important that a child receive a dilated examination once a year if the child is diagnosed with juvenile diabetes? Approximately how many children under age with juvenile diabetes are treated for eye- related problems?

The American Academy of Ophthalmology recommends a yearly eye exam beginning five years after the diagnosis of diabetes. Diabetic retinopathy almost never occurs before puberty and it is not common for older teenagers to need treatment. However, yearly exams are extremely important in order to prevent serious loss of vision in those that do need treatment.

Is there a cause and effect relationship between adult onset diabetes and macular degeneration? Will careful control of the diabetes lessen the progress of macular degeneration?

There is no known relationship between type 2 diabetes and macular degeneration.

I have had laser treatments for diabetic retinopathy. One eye still has neovascularization. What additional treatments are there?

Laser surgery usually causes neovascularization to shrink, but often it does not disappear. If it is not bleeding, growing or causing distorted vision, it probably does not need any further treatment. If the remaining neovascularization does cause vision problems, more laser or vitrectomy surgery may be recommended.

Is it possible to be suffering from diabetic retinopathy but not have any other outward symptoms of diabetes? Would this disease be easily diagnosed when the patient has undergone intense eye exams or can this be easily mistaken for other eye diseases? My daughter has been diagnosed with a “cone-rod dystrophy.” Can this be mistaken for diabetic retinopathy?

Cone-rod dystrophy would not be mistaken for diabetic retinopathy. The two conditions are very different. Once in a while, diabetic retinopathy is found in someone who does not know they have had diabetes for years. The American Diabetes Association estimates there are 8 million Americans who have undiagnosed diabetes.

Is there a cure for partial sight loss as a consequence of diabetic retinopathy ?

It depends on the cause of the vision loss. For example, laser surgery for macular edema will prevent further visual loss more often than it will improve vision. If the macula is not damaged and vision is blurred because of vitreous hemorrhage, sight may return to normal after the blood clears.

What diet would you recommend for people having diabetic retinopathy (zinc rich, etc.)?

There are no special dietary supplements recommended for diabetic retinopathy. It is very important to follow your regular diabetic diet.

Can diabetic retinopathy be treated with surgery, e.g. replacing part of the retina/macula?

Vitrectomy surgery can remove blood and scar tissue from the eye in people with severe proliferative diabetic retinopathy. Unfortunately, doctors cannot yet replace the retina/macula.

Can you tell me if the damage done from diabetic retinopathy can be healed or reconstructed so the vision loss is not permanent?

It is important to know that the results of the Diabetes Control and Complications Trial (DCCT)study showed that good control of blood sugars decreased the development of diabetic retinopathy by 75% in patients with no diabetic retinopathy at the start of the study. If diabetic retinopathy was present at the start of the study, there was a decrease in the rate of progression by 50% compared to those who did not control their blood sugars well.

Once diabetic retinopathy occurs, if it progresses to a certain point, then laser treatment decreases the chances of visual loss. Finally, if severe visual loss occurs, sometimes vitrectomy (a surgical procedure) can restore vision in some cases.

Overall, if patients are followed carefully, blindness can be avoided in 90% of patients with diabetic retinopathy.

I am interested in learning more about diabetic retinopathy. Could you tell me how many Americans each year are diagnosed with diabetic retinopathy? Are there any breakthroughs in diagnosis or treatment that I should know about?

There are an estimated 65,000 new cases of proliferative diabetic retinopathy and 75,000 new cases of diabetic macular edema each year. In addition, there are 8,000 new cases of blindness caused by complications of diabetes reported yearly.

Studies have shown that timely laser surgery can reduce the risk of visual loss from proliferative diabetic retinopathy by 90%, and can reduce the risk of moderate visual loss from diabetic macular edema by 50%.

The most important recent study has been the Diabetes Control and Complications Trial which showed that compared to patients with poor sugar control, in patients without diabetic retinopathy, tight control decreased the rate of progression by 75%. If diabetic retinopathy was present tight control decreased the rate of progression by 50%. Once diabetic retinopathy reached certain thresholds, then laser treatment can decrease the progression of visual loss as well . There are ongoing studies into the causes of development of abnormal blood vessels in the eye in diabetes as well as what causes the loss of normal blood vessels in diabetes.

Disclaimer: The responses provided through this service are not intended to replace consultation with an ophthalmologist. This question and answer service is intended for general educational purposes only and the responses represent the approach of the responding physician given the facts presented, not necessarily the only or best method or procedure in every case. Please refer to the Academy’s full disclaimer.

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