What is a cataract?

A cataract is a clouding of the eye’s naturally clear lens. The lens focuses light rays on the retina the layer of light-sensing cells lining the back of the eye to produce a sharp image of what we see. When the lens becomes cloudy, light rays cannot pass through it easily, and vision is blurred.

What causes cataract?

Cataract development is a normal process of aging, but cataracts also develop from eye injuries, certain diseases, or medications. Your genes may also play a role in cataract development.

How can a cataract be treated?

A cataract may not need to be treated if your vision is only slightly blurry. Simply changing your eyeglass prescription may help to improve your vision for a while.

There are no medications, eye drops, exercises, or glasses that will cause cataract to disappear or to prevent them from forming.

Surgery is the only way to remove a cataract. When you are no longer able to see well enough to do the things you like to do, cataract surgery should be considered.

In cataract surgery, the cloudy lens is removed from the eye through a surgical incision. In most cases, the natural lens is replaced with a permanent intraocular lens (IOL) implant.

What can I except if I decide to have cataract surgery?

BEFORE SURGERY

To determine if your cataract should be removed, your ophthalmologist will perform a thorough eye examination. Before surgery, your eye will be measured to determine the proper power of the intraocular lens that will be placed in your eye. Ask your ophthalmologist if you should continue taking your usual medications before surgery. You should make arrangements to have someone drive you home after surgery.

THE DAY OF SURGERY

Surgery is usually done on an outpatient basis, either in a hospital or an ambulatory surgery center. You may be asked to skip breakfast, depending on the time of your surgery.

When you arrive for surgery, you will be given eye drops and perhaps a mild sedative to help make you comfortable. A local anesthetic will numb your eye. The skin around your eye will be thoroughly cleansed, and sterile coverings will be placed around your head. You may see light and movement, but you will not be able to see the surgery while it is happening.

Under an operating microscope, a small incision is made in the eye. In most cataract surgeries, tiny surgical instruments are used to break apart and remove the cloudy lens from the eye. The back membrane of the lens (called the posterior capsule) is left in place.

A plastic, acrylic, or silicone intraocular lens is implanted in the eye to replace the natural lens that was removed.
After surgery is completed, your doctor may place a shield over your eye. After a short stay in the outpatient recovery area, you will be ready to go home.

FOLLOWING SURGERY

You will need to:
-use the eye drops as prescribed;
-be careful not to rub or press on your eye.
-avoid strenuous activities until your ophthalmologist tells you to resume them
-ask your doctor when you can begin driving
-wear eyeglasses or an eye shield, as advised by your doctor.
-You can continue most normal daily activities.
-Over-the-counter pain medicine may be used, if necessary.

Will cataract surgery improve my vision?

The success rate of cataract surgery is excellent. Improved vision is achieved in the majority of patients if other vision-limiting problems are not present.

Complications after cataract surgery?

Though they rarely occur, serious complications of cataract surgery are:
-Infection
-Bleeding
-Detachment of the retina.
-Call your ophthalmologist immediately if you have any of the following symptoms after surgery:
   --pain not relieved by pain medication
   --loss of vision
   --nausea, vomiting, or excessive coughing
   --injury to the eye.
-The lens capsule (the part of the eye that holds the lens in place) sometimes becomes cloudy several months or years after the original cataract operation. If the cloudy capsule blurs your vision, your ophthalmologist can perform a second procedure using a laser.
During the second procedure, called a posterior capsulotomy, a laser is used to make an opening in the cloudy lens capsule, restoring normal vision.

Other eye problems such as macular degeneration (aging of the retina), glaucoma, or diabetic retinopathy may limit vision after surgery. Even with these problems, cataract surgery may still be worthwhile. During your examination before the surgery, we can detect these problems and treat them before or during the cataract surgery. Talk to your ophthalmologist to learn more about cataract surgery and its risks and benefits.

Keratoconus is an uncommon condition in which the normally round, dome-like cornea (the clear front window of the eye) becomes thin and develops a cone-like bulge.
Keratoconus literally means “cone-shaped cornea.”
The cornea is a very important part of your eye. Light enters the eye through the cornea, which refracts, or focuses, the light rays so that you can see clearly. With keratoconus, the shape of the cornea is altered, distorting your vision. Keratoconus can make some activities difficult, such as driving, typing on a computer, watching television or reading.

WHAT ARE THE SYMPTOMS OF KERATOCONUS?

Keratoconus usually affects both eyes, though symptoms in each eye may differ. Symptoms usually start to occur in people who are in their late teens and early twenties and may include:
• mild blurring of vision;
• slight distortion of vision;
• increased sensitivity to light;
• glare;
• mild eye irritation.
The rate of progression varies. Keratoconus will often progress slowly for 10 to 20 years and then suddenly stop.
As the condition progresses, most common symptoms include:
• increased blurring and distortion of your vision;
• increased nearsightedness or astigmatism;
• Frequent eyeglass prescription changes.
Occasionally, keratoconus can advance rapidly, causing the cornea to become scarred. Scar tissue on the cornea causes the cornea to lose its smoothness and clarity. As a result, even more distortion and blurring of vision can occur.

WHAT CAUSES KERATOCONUS?

The cause of keratoconus is still not known. Some researchers believe that genetics play a role, since an estimated 10% of people with keratoconus also have a family member with the condition.

HOW IS KERATOCONUS TREATED?

•Treatment often depends on the severity of the condition. During early stages, vision can be corrected with eyeglasses. As the condition progresses, rigid contacts may need to be worn so that light entering the eye is refracted evenly and vision is not distorted. You should also refrain from rubbing your eyes, as this can aggravate the thin corneal tissue and make symptoms worse. If patient can't tolerate C.L., ICRS or cross linking or both can be done to him.
•When good vision is no longer possible with contact lenses, a corneal transplant may be recommended. This surgery is only necessary in about 10–20% of patients with keratoconus. In a corneal transplant, your ophthalmologist removes the diseased cornea from your eye and replaces it with a healthy donor cornea.
•While a corneal transplant will relieve the symptoms of keratoconus, it may not provide you with flawless vision; eyeglasses or contacts may still be needed to achieve your best vision.

For over 25 years doctors placed incisions in the cornea to treat nearsightedness. farsightedness, and astigmatism. In the early 1980s, they began looking at lasers to improve the precision and predictability of altering the shape of the cornea. Researchers found that the Excimer laser could remove tissue with up to 0.25 microns of accuracy. Now, in its second decade of use, the technologically advanced Excimer laser has added a tremendous amount of precision, control and safety to the surgical correction of vision errors. Using this remarkable technology, the cornea is reshaped to confirm to your glasses or contact lens prescription, thereby reducing or even eliminating a lifetime of dependence on corrective lenses for thousands of persons every year.

LASIK or Laser in the situ Keratomileusis offers a number of benefits over other forms of laser vision correction because it is performed under a protective layer of corneal tissue. As a result, there is less surface area to heal, less risk of scarring, less risk of corneal haze, less postoperative discomfort, less postoperative need for medications, and vision returns more rapidly, often within a day or so. LASIK can also treat a higher range of vision errors.

Refractive Errors

- MYOPIA (Nearsightedness):
Myopia or nearsightedness occurs when light rays are focused in front of the retina instead of directly on the retina
- HYPEROPIA (Farsightedness):
Hyperopia or farsightedness occurs when light rays are not bent enough to focus on the retina.
- ASTIGMATISM:
Regular astigmatism occurs when light rays are focused at more than one point on the retina.

LASIK (Laser in-Situ Keratomileusis):

The Excimer laser removes microscopic layers of corneal tissue to change its shape, allowing light rays to focus more directly on the retina

The LASIK procedure

• After your eye has been completely numbed using "eye drop" anesthesia, an eyelid holder will be placed between your eyelids to prevent you from blinking.
• Next an instrument known as a microkeratome makes a protective flap in the cornea. During this process you may feel a little pressure, but no discomfort. You will be asked to look directly at a target light while the laser reshapes the cornea, usually in less than a minute.
• To treat nearsightedness, the cornea must be made flatter. This is accomplished by removing tissue from the center of the cornea.
• To treat farsightedness, the central cornea must be steeper. This is accomplished by directing the laser beam to remove tissue from around this area.
• To treat astigmatism, the cornea must be made more spherical. By changing the pattern of the beam, tissue is removed in one direction more than the other.
• Then the protective flap is folded back in place where it bonds securely without the need for stitches. After LASIK some patients report a slight discomfort that usually goes away within twelve to twenty four hours.

Are You A Candidate For LASIK?

-The Ideal Candidate
In general. the ideal candidate for LASIK is over 18 years of age and has healthy corneas. Candidates must not have had a significant increase in their prescription in the last 12 months. People with certain medical conditions or women who are pregnant may not be good candidates for LASIK.

-In The Blink Of An Eye
It takes only seconds to treat a lifetime of nearsightedness. farsightedness and astigmatism. Find out if you are a candidate for this life changing procedure by calling your eye doctor to schedule a personal consultation. Should your vision fall within the range of correction for LASIK, more comprehensive tests may be necessary

What is glaucoma?

Glaucoma is a disease of the optic nerve, which is the part of the eye that carries the images we see to the brain. The optic nerve is made up of many nerve fibers, like an electric cable containing numerous wires. When pressure inside the eye increases, damage to the optic nerve fibers may occur, causing blind spots to develop. These blind spots usually go unnoticed by the patient until the optic nerve is significantly damaged. If the entire nerve is destroyed, blindness results.
Early detection and treatment by your ophthalmologist are the keys to prevent optic nerve damage and blindness from glaucoma.

What causes glaucoma?

Clear liquid, circulates inside the front part of the eye. A small amount of
this fluid is produced constantly, and an equal amount flows out of the eye through a microscopic drainage system, maintaining a constant level of pressure within the eye. (This liquid is not part of the tears on the outer surface of the eye.).
If the drainage area for this fluid -called the drainage angle- is blocked, the excess fluid cannot flow out of the eye. Fluid pressure within the eye will increase, pushing against the optic nerve and potentially causing damage.

What are the different types of glaucoma?

Chronic simple glaucoma:

This is the most common form of glaucoma. The risk of developing chronic open-angle glaucoma increases with age, usually above 50 years old. The drainage pores of the eye becomes narrower over time, and pressure within the eye gradually increases.

Chronic open-angle glaucoma damages vision so gradually and painlessly that you are not aware of trouble until the optic nerve is already injured.

Angle-closure glaucoma:

Sometimes the drainage angle of the eye may become completely blocked by the iris (the part that makes eyes blue, brown or green). You can imagine this occurring much like a sheet of paper floating near a drain. If the paper suddenly drops over the opening, the flow is abruptly blocked.
When eye pressure builds up suddenly, an acute angle-closure glaucoma attack occurs.
Symptoms may include:
• Blurred vision; severe eye pain; headache;
• Rainbow-colored halos around lights; nausea and vomiting.
This is a true eye emergency. If you have any of these symptoms, call your ophthalmologist immediately. Unless this type of glaucoma is treated quickly, blindness can result.

Normal Tension Glaucoma

In the some patients, the optic nerve maybe affected by the normal range of pressure. Decreasing the pressure further and supporting the optic nerve can prevent further damage.

What is dry eye?

Some people do not produce enough tears to keep the eye comfortable. This is known as dry eye. Tears are produced by two different methods. One method produces tears at a slow, steady rate and is responsible for normal eye lubrication. The other method produces large quantities of tears in response to eye irritation or emotions. Tears that lubricate are constantly produced by a healthy eye. Excessive tears occur when the eye is irritated by a foreign body or when a person cries.

What are the symptoms of dry eye?

The usual symptoms include:

• stinging or burning eyes;
• scratchiness;
• stringy mucus in or around the eyes;
• eye irritation from smoke or wind;
• excess tearing;
• difficulty wearing contact lenses.

Excess tearing from "dry eye" sounds illogical, but if the tears responsible for maintenance lubrication do not keep the eye wet enough, the eye becomes irritated. When the eye is irritated, the lacrimal gland produces a large volume of tears which overwhelms the tear drainage system. These excess tears then overflow from your eye.

What is the tear film?

A film of tears, spread over the eye by a blink, makes the surface of the eye smooth and clear. Without our tear film, good vision would not be possible.

The tear film consists of three layers:
• an oily layer;
• a watery layer;
• a layer of mucus.

The oily layer, produced by the meibomian glands, forms the outermost surface of the tear film. Its main purpose is to smooth the tear surface and reduce evaporation of tears.

The middle watery layer makes up most of what we ordinarily think of as tears. This layer, produced by the lacrimal gland, cleanses the eye and washes away foreign particles or irritants.

The inner layer consists of mucus produced by the conjunctiva. Mucus allows the watery layer to spread evenly over the surface of the eye and helps the eye remain wet. Without mucus, tears would not adhere to the eye.

What causes dry eye?

• Tear production normally decreases as we age. Although dry eye can occur in both men and women at any age, women are most often affected. This is especially true after menopause.
• Dry eye can also be associated with arthritis and accompanied by a dry mouth. People with dry eyes, dry mouth and arthritis are said to have Sjogren's syndrome.
• A wide variety of common medications ­prescription and over-the-counter-can cause dry eye by reducing tear secretion. Be sure to tell your ophthalmologist the names of all the medications you are taking, especially if you are using:
  · diuretics;
  · beta-blockers;
  · antihistamines;
  · sleeping pills;
  · medications for "nerves";
  · pain relievers.

Since these medications are often necessary, the dry eye condition may have to be tolerated or treated with "artificial tears." People with dry eye are often more prone to the toxic side effects of eye medications, including artificial tears. For example, the preservatives in certain eye drops and artificial tear preparations can irritate the eye. Special preservative-free artificial tears may be required.

How is dry eye diagnosed ?

An ophthalmologist is usually able to diagnose dry eye by examining the eyes. Sometimes tests that measure tear production may be necessary. One test, called the Schirmer tear test, involves placing filter-paper strips under the lower eyelids to measure the rate of tear production under various conditions. Another uses a diagnostic drop (fluorescein or Rose Bengal) to look for certain staining patterns.

How is dry eye treated?

ADDING TEARS
Eye drops called artificial tears are similar to your own tears.
They lubricate the eyes and help maintain moisture.
Artificial tears are available without a prescription. There are many brands on the market, so you may want to try several to find the one you like best.

Preservative-free eye drops are available if you are sensitive to the preservatives in artificial tears. If you need to use artificial tears more than every two hours, preservative-free brands may be better for you. Solid artificial tear inserts that are placed inside the lower lid on a daily basis and gradually release lubricants may be beneficial to some people.
You can use the tears as often as necessary-once or twice a day or as often as several times an hour.

CONSERVING THE TEARS
Conserving your eyes' own tears is another approach to keeping the eyes moist.

Tears drain out of the eye through a small channel into the nose (that is why your nose runs when you cry). Your ophthalmologist may close these channels either temporarily or permanently. The closure conserves your own tears and makes artificial tears last longer.

OTHER METHODS
Tears evaporate like any other liquid. You can take steps to prevent evaporation.
Anything that may cause dryness, such as an overly warm room, hair dryers or wind, should be avoided by a person with dry eye. Smoking is especially bothersome.

Some people with dry eye complain of scratchy eyes" when they wake up. This symptom can be treated by using an artificial tear ointment at bedtime. Use the smallest amount of ointment necessary for comfort, since the ointment can cause your vision to blur temporarily.

What is the cornea?

The cornea is the clear front window of the eye that covers the colored iris and the round pupil. Light is focused while passing through the cornea so we can see. To stay clear, the cornea must be healthy.

How can an unhealthy cornea affect vision?

If the cornea is damaged, it may become swollen or scarred, and its smoothness and clarity may be lost. Scars, swelling or an irregular shape cause the cornea to scatter or distort light, resulting in glare or blurred vision.


What conditions may require corneal transplants?
• corneal failure after other eye surgery, such as cataract surgery;
• keratoconus, a steep curving of the cornea;
• hereditary corneal failure, such as fuchs' dystrophy;
• scarring after infections, especially after herpes;
• rejection after first corneal transplant.
• scarring after injury,

What happens if you decide to have a corneal transplant?

BEFORE SURGERY
• Once you and your ophthalmologist decide you need a corneal transplant, your name is put on the list at the local eye bank. Usually, the wait for a donor cornea is not very long.
• Before a cornea is released for transplant, the eye bank tests the human donor for the viruses that cause hepatitis and AIDS. The cornea is carefully checked for clarity.
• Your ophthalmologist may request that you have a physical examination and other special tests. If you usually take medications, ask your doctor if you should continue using them.

THE DAY OF SURGERY
• Surgery is often done on an outpatient basis. You may be asked to skip breakfast, depending on the time of your surgery. Once you arrive for surgery, you will be given eye-drops and perhaps a sedative to help you relax.
• Either local or general anesthesia is used, depending on your age, medical condition and eye disease. You will not see the surgery while it is happening. Your eye will be held open with a lid speculum or other method.

THE OPERATION
• The eyelids are gently opened. The ophthalmologist will view your eye through a microscope and measure your eye for the corneal transplant.
• The diseased or injured cornea is carefully removed from the eye. Any necessary additional work within the eye, such as removal of a cataract, is completed. Then the clear donor cornea is sewn into place.
• When the operation is over, the doctor wilt usually place a shield over your eye.

AFTER SURGERY
If you are an outpatient, you may go home after a short stay in the recovery area. You should plan to have someone else drive you home. An examination at the doctor's office will be scheduled for the following day.

You will need to:
• use the eye-drops as prescribed;
• be careful not to rub or press on your eye;
• use over-the-counter pain medicine, if necessary;
• continue normal daily activities, except exercise;
• ask your doctor when you can begin driving;
• wear eyeglasses or an eye shield as advised by your doctor;
• if you have any questions about your home care instructions, call your doctor.
Your ophthalmologist will decide when to remove the stitches, depending upon the health of the eye and rate of healing. Usually, it will be several months before stitches are removed.

What complications can occur?

• Corneal transplants are rejected 5% to 30% of the time. The rejected cornea clouds and vision deteriorates. Most rejections, if treated promptly, can be stopped with minimal injury. Warning signs of rejection are:
• persistent discomfort;
• light sensitivity;
• redness;
• change in vision.
Any of these symptoms should be reported to your ophthalmologist immediately. Other possible complications include:
• Infection;
• Bleeding;
• swelling or detachment of the retina;
• Glaucoma.
• Cataract.

All of these complications can be treated.
A corneal transplant can be repeated, usually with good results, but the overall rejection rates for repeated transplants are higher than for the first transplant.
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Irregular curvature of the transplanted cornea (astigmatism) may slow the return of vision but can also be treated. Vision may continue to improve up to a year after surgery. Most of the patients will be prescribed glasses to improve their vision
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Even if the surgery is successful, other existing eye conditions, such as macular degeneration (aging of the retina), glaucoma or diabetic retinopathy, may limit vision after surgery. Even with such problems, a corneal transplant may still be worthwhile.
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A successful corneal transplant requires care and attention on the part of both patient and physician. However, no other surgery has so much to offer when the unhealthy cornea is deeply scarred or swollen.
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Corneal transplant surgery would not be possible without the thousands of generous donors and their families who have donated corneal tissue so that others may see.
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There is no need to transplant all corneal layers. Corneal transplant is more specialized nowadays, we can transplant only anterior corneal layer or posterior corneal later for specific pathological conditions.
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Corneal Surgery now is more precise using Femto laser technology for preparing and doing the specialized anterior or posterior corneal grafting.
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N.B: In Egypt we depend on the imported cornea from the USA mostly as local corneal eye bank still form a debate. Hoping that this problem is solved as soon as possible as keratoplasty is an easy operation which can help many patients in Egypt to regain their vision.
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What Is Strabismus?

Strabismus is a visual defect in which the eyes are misaligned and point in different directions. The misalignment may always be noticeable, or it may come and go. One eye may be directed straight ahead, while the other eye is turned inward, outward, upward or downward. The turned eye may straighten at times and the straight eye may turn.
Strabismus is a common condition among children, affecting about four percent, but can also occur later in life. It occurs equally in males and females and may run in families. However, many people with strabismus have no relatives with the problem.

Vision and the Brain

With normal binocular (two-eyed) vision, both eyes are aimed at the same target. The visual portion of the brain fuses the two pictures into a single 3­ dimensional image.
When one eye turns, as in strabismus, two different pictures are sent to the brain. In a young child, the brain learns to ignore the image of the misaligned eye and see only the image from the straight or best seeing eye. This causes loss of depth perception and binocular vision. Adults who develop strabismus often have double vision because the brain is already trained to receive images from both eyes and cannot ignore the image from the turned eye.

Amblyopia

Normal alignment of both eyes during childhood allows good vision to develop in ; each eye. Abnormal alignment, as in strabismus, may cause reduced vision or amblyopia. The brain will recognize the image of the better seeing eye and ignore the image of the weaker or amblyopic eye. This occurs in approximately half the children who have strabismus.
Amblyopia can be treated by patching the preferred or better seeing eye to strengthen and improve vision in the weaker eye. If amblyopia is detected in the first few years of life, treatment is often successful. If adequate treatment is delayed until later, amblyopia or reduced vision generally becomes permanent. As a rule, the earlier amblyopia is treated, the better the visual result.

Causes and Symptoms of Strabismus

The exact cause of the eye misalignment that leads to strabismus is not fully understood.
Six eye muscles, controlling eye movement, are attached to the outside of each eye. In each eye, two muscles move the eye right or left. The other four muscles move it up or down and control tilting movements. To line up and focus both eyes on a single target, all eye muscles of each eye must be balanced and working together with the corresponding muscles of the opposite eye.
The brain controls the eye muscles which explains why children with disorders that affect the brain, such as cerebral palsy, Down's syndrome. hydrocephalus. and brain tumors often have strabismus. A cataract or eye injury that affects vision can also cause strabismus.
The primary symptom of strabismus is an eye that is not straight. Sometimes a youngster will squint one eye in bright sunlight or tilt their head in a specific direction to use their eyes together. Signs of faulty depth perception may also he noticed.

Detection and Diagnosis

Children should be examined by the family doctor, pediatrician, or ophthalmologist during infancy and preschool years to detect potential eye problems. This is particularly important if a relative has had strabismus or amblyopia.
In infants it is often difficult to determine the difference between eyes that appear to be crossed and true strabismus. Young children often have a wide, flat nose and a fold of skin at the inner eyelid that tends to hide the eye during side gaze, causing the eyes to appear crossed. This appearance of strabismus may improve as the child grows. True strabismus is not outgrown. An ophthalmologist can readily distinguish true from false strabismus.

Treatment

Treatment goals for strabismus are to preserve vision, to straighten the eyes, and to restore binocular vision. Depending on the cause of the strabismus, treatment may involve repositioning the unbalanced eye muscles, removing a cataract, or correcting other conditions which are causing the eyes to turn. After a complete eye examination, including a detailed study of the inner parts of the eye, an ophthalmologist can recommend appropriate optical, medical or surgical therapy. Covering or patching the good eye to improve vision in the amblyopic eye is often necessary.

Strabismus Surgery

• The eyeball is never removed from the socket during any kind of eye surgery. Strabismus surgery involves making a small incision in the tissue covering the eye which allows the ophthalmologist access to the underlying eye muscles. Which eye muscles are repositioned during the surgery depends upon the direction the eye is turning. It may be necessary to perform surgery on one or both eyes.
• When strabismus surgery is performed on children, a general anesthetic is required. Local anesthesia is an option for adults.
• Recovery time is rapid. People are usually able to resume their normal activities within a few days. After surgery, glasses or prisms may be useful. Over-or-under correction can occur and further surgery may be needed.
• Early surgery is recommended to correct strabismus because younger infants can develop normal sight and binocular vision once the eyes are straightened. As a child gets older, the chance of developing normal sight and binocular vision decreases. Crossed eyes can also have a negative effect on a child's self-confidence.
• As with any surgery, eye muscle surgery has certain risks. These include infection, bleeding, excessive scarring, and other rare complications that can lead to loss of vision. However, strabismus surgery is usually a safe and effective treatment for eye misalignment. It is not, however, a substitute for glasses or amblyopia therapy.

Summary

• Treatment for strabismus is most effective when the child is young.
• Children do not outgrow strabismus.
• Cosmetic straightening of the eyes remains possible at any age.
• Treatment for strabismus may be non­ surgical and include eye drops, exercises, or glasses.
• If surgical treatment is indicated, the earlier in life it is done, the better chance the child has of developing normal binocular vision.

1. Q: what is Low Vision

A: Low vision is a visual condition that affects millions especially seniors. Simply, it is a degree of visual impairment that cannot be adjusted completely to normal vision, even with the use of traditional eyeglasses or contact lenses (According to WHO: a man with low vision will have best corrected vision of less than 20/60 in the better eye).
In other word; Low vision could be defined as best corrected vision which is insufficient to do what your patient wants to do.

2. Q: Are there a difference between blindness and low vision?

A: Low vision should not be confused with blindness. Low vision patients still have some ability to see and the condition can often be improved under the care of a low vision specialist who will prescribe aids to assist a low vision patient.

3. Q: What are common symptoms o f low vision?

A: Although the degree of impairment varies, from one individual to another, and may or may not affect both eyes, Low Vision most often is a loss of central or reading vision and loss of side or peripheral vision. Other symptoms of low vision may include reduction or loss of color vision, difficulty in adapting , from light to dark environments, and reduction of the ability to, focus.

4. Q: What are causes of low vision?

A: A variety of disorders may lead to low vision including birth defects and injury, disease (particularly diabetes, glaucoma, inoperable cataract), trauma and aging. The most common condition that causes low vision in seniors is macular degeneration . Simply; this condition results from a breakdown of the macular cells that causes difficulty with reading and close work Vision.

5. Q: Is there a special examination for the low vision patient?

A: The "low vision examination" should be much more extensive than a regular eye examination. Often the initial examination will last more than one hour (or can be done in two visits). Low vision doctor will need to ask many lifestyle questions in order to determine the demands of your patient vision.
• The amount of remaining vision must be carefully, determined using specialized charts which are closer to the patient, and Have more gradations than the standard projected chart. The patient is instructed to use peripheral vision during testing, since central vision is often damaged.
• Then the amount of magnification needed to do the desired tasks must be determined for far tasks like driving, near tasks like reading and intermediate tasks like computing..
• There are various types of magnification devices called low vision aids, which can be utilized to help the patient perform tasks. The best form for each person and each task must he determined. For example, for seeing prices a hand magnifier usually works best, except for patients with a hand tremors.
• Visual, field evaluation in cases such as Glaucoma and Retinitis Pigmentosa is essential followed by evaluating the effect of field enhancers. Other factors like lighting, glare, contrast, mobility and more must be looked at by the Low Vision Doctor to come up with the best combination of "ingredients" to allow the patient to function.

6. Q: what happens after the exam?

A: After determining the visual needs, the doctor will advise the patient on a variety of low visions aids.
Depending on the severity of the impairment, patient may be prescribed high power glasses that are specially ordered and made with hand-ground lenses (either telescopic for distance such as the television; or microscopic for close work and Reading). He may prescribe electronic visual aids, glare control and enhancing filters, or contact lenses, to improve every day living. Training in the use of such devices is critical to the successful use of remaining vision. If the condition is less severe, the patient may simply be advised to use a magnifier and given suggestions on non-optical aids, such as large print books, enlarged phone dials, and high contrast watch faces.

7. Q: Who is offering training for Low visual Aids and who is taking care of the patient after that?

Most of low vision aids are not difficult to be used, however Low vision doctor and his assistants will train the patient to use his new device especially those needed for mobility and driving. But the patient is sent back to his referring doctor, for follow-ups and taking care of his eye health.

What Is Diabetic Retinopathy?

Diabetic retinopathy, the most common diabetic eye disease, occurs when blood vessels in the retina change. Sometimes these vessels swell and leak fluid or even close off completely. In other cases, abnormal new blood vessels grow on the surface of the retina.

The retina is a thin layer of light-sensitive tissue that lines the back of the eye. Light rays are focused onto the retina, where they are transmitted to the brain and interpreted as the images you see. The macula is a very small area at the center of the retina. It is the macula that is responsible for your pinpoint vision, allowing you to read, sew or recognize a face. The surrounding part of the retina, called the peripheral retina, is responsible for your side—or peripheral—vision.

Diabetic retinopathy usually affects both eyes. People who have diabetic retinopathy often don't notice changes in their vision in the disease's early stages. But as it progresses, diabetic retinopathy usually causes vision loss that in many cases cannot be reversed.

Diabetic Retinopathy Causes

When blood sugar levels are too high for extended periods of time, it can damage capillaries (tiny blood vessels) that supply blood to the retina. Over time, these blood vessels begin to leak fluids and fats, causing edema (swelling). Eventually, these vessels can close off, called ischemia. These problems are signs of non-proliferative diabetic retinopathy (NPDR).

As diabetic eye problems are left untreated, proliferative diabetic retinopathy (PDR) can develop. Blocked blood vessels from ischemia can lead to the growth of new abnormal blood vessels on the retina (called neovascularization) which can damage the retina by causing wrinkling or retinal detachment. Neovascularization can even lead to glaucoma, damage to the optic nerve that carries images from your eye to your brain.

Maintaining strict control of blood sugar and blood pressure, as well as having regular diabetic retinopathy screenings by your Eye M.D., are keys to preventing diabetic retinopathy and vision loss. Controlling blood sugar and also help to prevent the development of cataracts, as diabetes is a risk factor for cataracts.

Diabetic Retinopathy Symptoms

You can have diabetic retinopathy and not be aware of it, since the early stages of diabetic retinopathy often don't have symptoms.
As the disease progresses, diabetic retinopathy symptoms may include:

• Spots, dots or cobweb-like dark strings floating in your vision (called floaters);
• Blurred vision;
• Vision that changes periodically from blurry to clear;
• Blank or dark areas in your field of vision;
• Poor night vision;
• Colors appear washed out or different;
• Vision loss.

Careful management of your diabetes is the best way to prevent vision loss. If you have diabetes, see your eye doctor for a yearly diabetic retinopathy screening with a dilated eye exam — even if your vision seems fine — because it's important to detect diabetic retinopathy in the early stages. If you become pregnant, your eye doctor may recommend additional eye exams throughout your pregnancy, because pregnancy can sometimes worsen diabetic retinopathy.

Diabetic Retinopathy Treatment

The best treatment for diabetic retinopathy is to prevent it. Strict control of your blood sugar will significantly reduce the long-term risk of vision loss. Treatment usually won't cure diabetic retinopathy nor does it usually restore normal vision, but it may slow the progression of vision loss. Without treatment, diabetic retinopathy progresses steadily from minimal to severe stages.

Laser surgery
The laser is a very bright, finely focused light. It passes through the clear cornea, lens and vitreous without affecting them in any way. Laser surgery shrinks abnormal new vessels and reduces macular swelling. Treatment is often recommended for people with macular edema, proliferative diabetic retinopathy (PDR) and neovascular glaucoma.

Laser surgery is usually performed in an office setting. For comfort during the procedure, an anesthetic eye-drop is often all that is necessary, although an anesthetic injection is sometimes given next to the eye. The patient sits at an instrument called a slit-lamp microscope. A contact lens is temporarily placed on the eye in order to focus the laser light on the retina with pinpoint accuracy.

With laser surgery for macular edema, tiny laser burns are applied near the macula to reduce fluid leakage. The main goal of treatment is to prevent further loss of vision by reducing the swelling of the macula. It is uncommon for people who have blurred vision from macular edema to recover normal vision, although some may experience partial improvement.

A few people may see laser spots near the center of their vision following treatment. They usually fade with time, but may not disappear completely.
In PDR, the laser is applied to all parts of the retina except the macula (called PRP, or panretinal photocoagulation). This treatment causes abnormal new vessels to shrink and often prevents them from growing in the future. It also decreases the chance that vitreous bleeding or retinal distortion will occur. Panretinal laser has proven to be very effective for preventing severe vision loss from vitreous hemorrhage and traction retinal detachment.
Multiple laser treatments over time may be necessary. Laser surgery does not cure diabetic retinopathy and does not always prevent further loss of vision.

Vitrectomy surgery

Vitrectomy is a surgical procedure performed in a hospital or ambulatory surgery center operating room. It is often performed on an outpatient basis or with a short hospital stay. Either a local or general anesthetic may be used.
During vitrectomy surgery, an operating microscope and small surgical instruments are used to remove blood and scar tissue that accompany abnormal vessels in the eye. Removing the vitreous hemorrhage allows light rays to focus on the retina again.
Vitrectomy often prevents further vitreous hemorrhage by removing the abnormal vessels that caused the bleeding. Removal of the scar tissue helps the retina return to its normal location. Laser surgery may be performed during vitrectomy surgery.
To help the retina heal in place, your ophthalmologist may place a gas or oil bubble in the vitreous space. You may be told to keep your head in certain positions while the bubble helps to heal the retina. It is important to follow your ophthalmologist's instructions so your eye will heal properly.

Medication injections

In some cases, medication may be used to help treat diabetic retinopathy. Sometimes a steroid medication is used. In other cases, you may be given an anti-VEGF medication. This medication works by blocking a substance known as vascular endothelial growth factor, or VEGF. This substance contributes to abnormal blood vessel growth in the eye which can affect your vision. An anti-VEGF drug can help reduce the growth of these abnormal blood vessels.
After your pupil is dilated and your eye is numbed with anesthesia, the medication is injected into the vitreous, or jelly-like substance in the back chamber of the eye. The medication reduces the swelling, leakage, and growth of unwanted blood vessel growth in the retina, and may improve how well you see.
Medication treatments may be given once or as a series of injections at regular intervals, usually around every four to six weeks or as determined by your doctor.