Centres of Excellence

• Dry AMD: The retina becomes thinner (atrophic) and stops functioning. This may cause some people to detect “blank” areas in their central vision. The vision loss due to this Dry AMD is not very severe as compared to the wet AMD. While there is no treatment available for people with dry AMD, various low vision aids are available to help these people see well and perform daily activities.
• Wet AMD: Abnormal blood vessels grow under the macula. These abnormal vessels leak fluid and blood, and thus cause swelling and scar tissue formation, leading to distorted vision and severe vision loss.

The vision lost due to AMD is generally irreversible, and the treatment methods try to preserve vision but can not improve vision. Hence it is important to detect this disease at an early stage, before it has caused significant vision loss.

In the early stages of AMD, a person's vision may become blurred or distorted. A retinal examination, with the help of special tests like Fluorescein Angiography etc. can help the eye specialist to diagnose the condition. Since many times the patient may not notice the initial distortion or blurring of vision, the key to preventing vision loss due to AMD is regular eye examinations for patients above 40 years of age.These regular checkups are also useful in detecting other potentially serious diseases like Glaucoma.

Untreated, AMD is known to progress and lead to further loss of vision, the rate of deterioration being faster in the wet type. Antioxidants and Multivitamin capsules may have a role in preventing or decreasing the speed of progression of the disease. In wet AMD, additional methods of treatment are required to arrest or at least retard the progression of the disease. Many methods have been tried and are being developed. The best-suited treatment modality is decided by the eye specialist after discussing with the patient. One may need to use a combination of various therapies. The most popular and established modes of treatment are:

• Conventional Laser: burns the abnormal blood vessels and thus stops the leakage. However, since it also damages the normal retina structures, it may itself lead to decreased vision. Hence, it is suitable only in selected cases where the new vessels are not very close to the central macular area.
• Anti-VEGF agents: The available agents are Lucentis, Avastin, and  Macugen. When injected into your eye (intravitreal), it works by inhibiting the growth of abnormal blood vessels in the back of the eye. By blocking the stimulus, it can stop the blood vessels leaking and growing. In many cases it actually causes the blood vessels to regress, and even improves vision.
• Photo Dynamic therapy (PDT): involves the injection of a special dye that binds to the abnormal blood vessels. After the injection, this area is treated by a special laser which selectively destroys the abnormal blood vessels without much damage to the normal structures.
• Transpupillary Thermo-Therapy (TTT): uses a special delivery system of Infra red laser which heats up the abnormal blood vessels and causes its closure, without much damage to the normal retinal structures. More than one sitting of these treatments may be required. The aim of the treatment is to try to preserve the vision and not to improve the vision. This technique is not often used nowadays, and may find use in some selected cases only.
  
  A special Amsler Grid is given to the patient to monitor the progress of the disease. With timely and proper treatment, and regular follow ups, majority of the patients are able to maintain useful vision to perform their daily activities and lead a socially productive life.

Diabetes can affect the eyes and vision in a number of ways. It may lead to frequent fluctuations in vision, cataract in young age, decreased vision due to involvement of optic nerve, temporary paralysis of the muscles controlling the movement of eyes and thus double vision. The most significant complication of diabetes in eye is diabetic retinopathy and its complications.

Retina is the inner most layer of the eye that is sensitive to light. Diabetes affects the small vessels of the retina in the eye. There are various stages of diabetic retinopathy:

• Non-proliferative or background diabetic retinopathy : When blood vessels in the retina are damaged, they can leak fluid or bleed. This causes the retina to swell and form deposits called exudates. This is an early form of diabetic retinopathy and may not lead to any decrease in vision, but it can lead to other more serious forms of retinopathy that affect the vision.
• Macular edema : The fluid and exudates collects in the macula (the part of the retina that allows us to see fine details), thus decreasing the vision. Sometimes there may be a macular edema without any loss of vision. Therefore it is important to have periodic checkup to detect and treat these conditions at an early stage.
• Proliferative diabetic retinopathy: This is an advanced stage of diabetic retinopathy, where the blood supply of retina is compromised. In response to this, new fragile blood vessels grow on the surface of the retina (neovascularization). These new vessels are very fragile and bleed easily. These may lead to serious vision problems if they bleed into the vitreous (the clear, jelly-like substance that fills the center of the eye) which is known as vitreous hemorrhage. This prevents the light from reaching the retina and thus can blur the vision.
  
  The new blood vessels and the bleed into the vitreous can also cause scar tissue to develop, which can pull the retina away from the back of the eye. This is known as retinal detachment, and can lead to blindness if untreated.
  
  In addition, abnormal blood vessels can grow on the iris (the colored part in the front of your eye, which can lead to glaucoma).

The longer the person has diabetes, the greater are his/her chances to develop diabetic retinopathy. Almost 80% of people, who have diabetes for 15 years or more, have some damage to the blood vessels in their retina. The other risk factors are high blood pressure, anemia, kidney diseases, and pregnancy.

There is no treatment that can prevent diabetic retinopathy altogether. Persons with any form of diabetes may develop diabetic retinopathy. But it has been proven that a good control of diabetes can delay and slow down the rate of progress of diabetic retinopathy and its complications. Besides a good control of blood sugar, one must exercise regularly, keep the blood pressure under control, avoid smoking, and avoid obesity.

You might not know that you are having diabetic retinopathy, as there are no symptoms in the earlier stages of the disease. Therefore it is essential to have periodic evaluation of your eye by an ophthalmologist to detect the condition early. Early diagnosis and timely treatment is very essential in preventing the complications of this disease and thus maintaining vision.

If you have diabetes, you should get a yearly examination with your ophthalmologist. Your pupils may be dilated with eyedrops, so that your ophthalmologist may have a good look at the back of your eye. Once you develop diabetic retinopathy, then your ophthalmologist will advise you if you need some investigations, treatment or just need to follow up. In these cases the frequency of follow up visits is decided on basis of the severity of the disease.

Your vision is assessed by the usual charts. The back of your eye is examined after dilating your pupils, using an instrument called ophthalmoscope. Sometimes your ophthalmologist may advise a special test called Fluorescein angiography.

It is test in which a series of photographs of the retina are taken with the help of a special camera. These photographs are taken after giving the patient an injection of a yellow dye. This dye reaches the retina through the blood stream and helps in seeing the blood vessels of retina more clearly. This test helps the doctor to determine which areas to be treated with laser.

The treatment of diabetic retinopathy is decided on the basis of the stage of the disease. In the very initial stages, it just requires periodic follow up to look for progression of disease. The ophthalmologist decides when to see a patient next depending upon the severity of changes in the retina.

Later when the disease is more advanced he/she may decide to treat it with one or more of the following options:

• Laser Treatment : There are well-defined criteria for laser therapy. Laser therapy is done when there is significant maculopathy, or when there are significant new blood vessels in the retina or iris.
• Anti-VEGF agents (Lucentis, Avastin, Macugen) : These agents are being used in some selective cases alone or in addition to laser treatment or surgery.
• Surgery : Vitrectomy surgery and other additional procedures may be required to manage the complications of diabetic retinopathy, like vitreous hemorrhage, retinal detachment, severe macular edema, etc.

Most sight threatening complications of diabetic retinopathy can be prevented by laser treatment if given early enough. It involves focusing and applying laser spots on the retina. There are two types of laser treatments depending upon the type of retinopathy:
Diabetic maculopathy: This is treated be applying laser spots in the region of macula to seal the leaking blood vessels.
Proliferative diabetic retinopathy: This condition requires more extensive application of laser in a wider area of retina. It helps the abnormal new vessels to shrink and disappear. It may require more than one sitting to complete the treatment.

It is important to remember that the laser treatment is done to prevent further loss of vision and not to improve the vision. It is highly effective and can prevent blindness in about 80% of the patients.

After the laser treatment, regular follow-ups are required to assess the effect of treatment and to monitor the progress of the disease.

Laser treatment is performed as an outpatient procedure, that is you don't have to be admitted for it. The pupil of the eye is dilated using eye drops. The eye is then numbed with drops (topical anesthetics) so that you don't feel the pain. The patient is seated on a machine and a small contact lens is placed on the cornea. Following this laser treatment is given by this very precise machine. During the treatment, you may be asked to move your eyes in certain directions.

The laser treatment may have a few side effects like decrease in the peripheral field of vision, decrease in color vision and difficulty in seeing at night. Sometimes it may also reduce the central vision. This is usually temporary but sometimes this may not improve.
Though no treatment is without any side effects, the risk of the laser treatment are far less than the risk of not having the treatment.

These agents (Lucentis, Avastin, Macugen) are emerging as the new modality of treatment for various stages of diabetic retinopathy and are showing very promising results. These agents are injected within the eye (intravitreal injection) in a very small painless procedure, inside the OT under aseptic precautions.

In some patients in which the disease is not controlled by the laser, or who have reached the advanced stage of disease, the ophthalmologist may advise a surgery called vitrectomy. The surgeon removes the blood filled vitreous and replaces it with a fluid, using very delicate instruments with the help of a microscope.

Since the blood in the vitreous cavity is replaced by a clear fluid, the light can reach the retina now. This may help restore vision.

Most of the complications of diabetic retinopathy that cause vision loss are preventable, provided they are detected early and treated. As you may not realize any problem in your vision initially, it is important that you have periodic checkups with an ophthalmologist.

No. The eye checkups do not prevent diabetic retinopathy, but recognize it at an early stage. This helps in preventing the vision threatening complications of diabetic retinopathy.

No. The aim of laser therapy is to preserve the vision and to prevent further loss of vision. It may not restore your vision once it is decreased.

Yes. The fluctuations in the blood glucose level in diabetes may lead to changes in the shape of the lens of eye. This changes the refractive power of the eye and manifests as frequently changing prescription of glasses.

The following symptoms would require you to contact your ophthalmologist early, even before your next scheduled appointment:

• Decrease in vision
• Sudden onset of red floaters noticed in front of eye
• Loss of a field of vision.

Do not bend down or do any strenuous activity. Contact your ophthalmologist at the earliest.

Yes. The diabetic retinopathy may worsen during pregnancy. Therefore, if you are a diabetic, contact your ophthalmologist before planning your pregnancy. After doing a check up, he or she may advise you to undergo laser treatment before commencing pregnancy. Moreover, during pregnancy, you must visit your ophthalmologist regularly to detect any worsening of the disease.

Special devices called low vision aids may help those who have very poor vision. These devices may help them to read and to perform their daily activities. Moreover, the ophthalmologist may issue them a certificate of visual disability that entitles them to certain benefits.

Yes. Diabetes may sometimes lead to sudden development of cataract in young. Moreover the onset of usual cataract is earlier in diabetics than in non-diabetics.
 

Presence of diabetic retinopathy suggests that other complications of diabetes in the body must also be taking place. These complications affect the kidney, heart, brain, peripheral nerves and blood vessels. Your physician treating you for diabetes would do the necessary checkups and advise you regarding the treatment.

Most commonly, retinal detachment occurs due to a hole/tear formation in the retina. Through this hole, liquefied vitreous, which is jelly like substance filling the eyeball, passes behind the retina and detaches it.
Tractional retinal detachment usually occurs in diabetics or other vascular diseases of the retina. Extensive membranes are formed on the retina, which on contracting, pull the retina up.
 

Presence of high degrees of myopia (minus power), injury to the eye, occurrence of retinal detachment in the fellow eye, occurrence of retinal detachment in the blood relatives, cataract surgery etc. are some of the factors that increase the risk of retinal detachment.

If one has any of the above mentioned risk factors, he/she should get regular retinal checkups. The pupils are dilated and the retina, especially the peripheral part, is checked thoroughly with the help of Indirect Ophthalmoscope. In case a retinal break or lesion is discovered, it can be treated by a simple preventive procedure of Laser or Cryopexy.

Direct injury to the eye can lead to retinal breaks, holes, or tears that may cause retinal detachment days, weeks, months, or even years after the incident. Therefore, every patient with significant eye injury must get a detailed retinal checkup after the injury, and thereafter at regular intervals to detect these possible retinal breaks. Trauma severe enough to cause a black eye, hemorrhage on the white part of the eye, hemorrhage within the eye, a penetration or laceration of the eye, cataract, light flashes, floaters, or decreased vision can be related to subsequent retinal detachment.

Perception of Flashes of light, or sudden onset of Floaters are common symptoms which may point towards the presence of a Retinal Tear or Retinal Detachment. A loss of field of vision or sudden decrease in central vision are symptoms of Retinal Detachment. The diagnosis is confirmed by a detailed retinal checkup by a retinal specialist. In case of poor visibility, B-scan Ultrasound test may be required to confirm the diagnosis.

When the retina stays detached for a long time, it starts to shrink and membranes form on it. This not only requires a major surgery, it also decreases the chances of success. Moreover, as the retina stays detached longer, it does not get adequate blood supply and thus loses the vision potential. This limits the ultimate gain of vision even after a successful reattachment of the retina.

A retinal tear without a detachment can be treated by a simple Laser or Cryopexy procedure. However a retinal detachment requires a major surgery to settle the retina. Depending upon the severity of the case and other factors, one of the two options are generally used:

• Retinal surgery
  In selected cases, this relatively simpler surgery called Scleral buckling is done, where a silicon plastic is placed on the outside of the eye and sewn in place (the scleral buckle is very small and not visible after surgery). It pushes the sclera toward the tear in the retina and closes it to settle the retina.

• Vitreo-Retinal Surgery
  In more severe or advanced cases, along with Scleral buckling, vitrectomy may be necessary. In this procedure, the vitreous gel is removed using special instruments, and then retina is settled in place and is fixed there with the help of laser. To support the retina either Silicone oil or special Gas is injected in the eye to replace the vitreous. This injected oil is inert in nature and is generally removed later at a suitable time after the initial surgery.

Post-operatively, the patient may be needed to be maintained in a special position to support the retina. This is especially required in cases of Vitreo-retinal surgeries. During the follow up visits, supplementary laser treatments may be advised. As it is a major surgery, some of the patients may also develop complications like glaucoma, cataract, infection, corneal opacity etc. due to the detachment or due to the treatment. The fellow eye is also at a risk for future retinal detachment and must be checked at regular intervals. Hence a regular follow up is very important.

The primary aim of the surgery is to re-attach the retina. The vision regained primarily depends upon the 'strength' of retina, which in turn depends upon many factors, especially the duration of detachment. The earlier the surgery is done, the better are the visual results. The vision regained may not be the same as that before the detachment occurred. But in case no surgery is done, the vision is likely to deteriorate further leading to blindness, shrinking and disfiguration of eyeball. Hence it is important to do the surgery as soon as possible.

In some patients re-detachment may occur due to formation of membranes on the retina (called Proliferative Vitreo Retinopathy). Also in 20-30% of patients operated for Vitreoretinal surgery, retinal detachment may recur after the removal of Silicone Oil. Hence the patients are required to maintain regular post-operative follow up for a long time even after the surgery