Retina

The retina is like the film in a camera. It is the seeing tissue of the eye. When the focused light hits the retina, a picture is created and sent to the brain through the optic nerve (the nerve of the eye), thus giving us vision.

Retina has two parts: The Peripheral retina and Central Macula. Macula being the central part, is capable of producing sharp and clear image. This clear images enable us to read , write and do all fine work.

Conditions like Diabetes, Age related Macular degeneration and Macular holes can damage retina.

In VISION CARE we treat the diabetic retinopathy ,age related macular degeneration , macular edema, hyper tensive retinopathy , retinal detachment under the guidance from the retinal specialist Dr. Sachin V. Mahuli

	Vision with Macular Degeneration	Macular Degeneration

In VISION CARE we offer the following facilities

• detail fundus check up with dilation ,
• laser treatment for diabetic patients,hyeypertensive changes in the eye
• vein and artery occlusion
• age related macular degeneration
• retinal detachment

Laser Treatment
Laser is a highly concentrated light that is beamed onto the retina to treat the desired area. It is a painless Out Patient procedure, lasting about 10-30 minutes that does not require admission. It may require more than one sitting to complete the treatment. In majority of cases, the aim of laser treatment is to try to prevent further loss of vision. It can not regain the vision already lost due to retinal disease. After the laser treatment, the patient may require to undergo repeat Fluorescein Angiography at a later date to monitor the response, and may require more laser if indicated.

Lasers are commonly used in the following conditions:

Diabetic Retinopathy – the damaged small vessels of the retina leak fluid and blood, causing swelling of the retina. These changes decrease vision if the central part is affected. Laser is done to seal these leaks. However laser is done to prevent or retard further loss of vision and not to improve vision. In severe changes when new blood vessels have grown (Proliferative Diabetic Retinopathy), multiple sittings of laser are needed to regress these vessels. This is called Pan Retinal Photocoagulation and is highly effective in preventing severe visual loss due to recurrent bleeding in vitreous.

Retinal tears and holes – In a retinal tear or a hole without a retinal detachment, laser is done prophylactically to seal the hole and prevent or limit the detachment.

Age Related Macular Degeneration – In patients with wet type of AMD not involving the central part, laser can be done to close the Choroidal Neovascular Membrane. This can prevent severe visual loss. However in patients with central involvement, other specific lasers are used like- Photo Dynamic Therapy (PDT) with verteporfin and Transpupillary Thermo Therapy (TTT) with Diode laser.

Other Retinal vascular disorders – like retinal vein occlusions and Eales disease also require laser at times. In venous occlusions, the central retina may swell up due to fluid collection leading to reduced vision. Such cases require laser to decrease the swelling, which may help in improving the vision. Venous occlusions may also lead to new vessel formation, which needs laser to regress these vessels. Similarly in Eales disease, laser is required to reduce recurrent vitreous hemorrhages. Laser is also useful in selected cases with Central Serous Retinopathy (CSR).

How can diabetes affect eye?

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.

What is diabetic retinopathy?
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).

What are the risk factors for diabetic retinopathy?
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.

Can something be done to prevent diabetic retinopathy?
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.

How do I know if I have diabetic retinopathy?
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.

How frequently should I get my eye examined?
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.

What are the tests done for diabetic retinopathy?
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.

What is 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.

What is the treatment for diabetic retinopathy?
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.

What is Laser treatment?
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.

How is the laser performed?
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.

What are the side effects of laser?
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.

What are Anti VEGF agents, and what is their role in managing diabetic retinopathy?
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.

What surgery is done for diabetic retinopathy?
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.

Why are regular eye tests so important?
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.

Would eye checks prevent diabetic retinopathy?
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.

Can I get back my vision after laser surgery?
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.

The power of my glasses keeps changing very frequently. Does it have something to do with diabetes?
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.

What are the warning symptoms to contact my ophthalmologist early, if I have diabetic retinopathy?
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

What precautions should I take if I notice blood (red floaters) in my vision?
Do not bend down or do any strenuous activity. Contact your ophthalmologist at the earliest.

Does pregnancy have any effect on diabetic retinopathy?
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.

If someone loses his/her vision due to diabetic retinopathy, what are the other helps available?
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.

Is there any association of cataract with diabetes?
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.

Is there any association of glaucoma with diabetes?
Yes. Diabetics are a higher risk of having glaucoma.

Is there any association between diabetic retinopathy and other complications of diabetes?
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.

FLASHES AND FLOATERS
Flashes and Floaters are symptoms experienced by many people. Flashes are experienced as a lighting streak, originating within the eye, in the field of vision. Flashes are most often noticed at night or in a dark room. Floaters are perceived as freely mobile single or multiple black spots in the line of vision. Majority of times these flashes and floaters are harmless. However, these may also point towards more serious conditions of retina like retinal breaks, retinal detachment, vitreous hemorrhage etc., which if not treated promptly, may lead to severe loss of vision. Hence it is important not to ignore these symptoms and get a detailed retinal checkup to prevent serious complications.

What causes Flashes and Floaters?
The interior portion of the human eye is filled with a gelatinous substance called vitreous. With time, the vitreous gel liquefies and eventually pulls away or separates from the back of the eye where it is attached to the retina. This process is called Posterior Vitreous Detachment (PVD) and is a normal event occurring in most people somewhere between the ages of 40-70 years.

During this separation of PVD, the pull on the retina is perceived by some people as a Flash of light. These may occur anywhere in the field of vision. If the gel is abnormally adherent to the retina, or the retina is weak in a certain area, a retinal tear can occur. Once a retinal tear develops there is a significant risk of the liquid vitreous going through the break and causing retinal detachment.

Any opacity in the vitreous, which comes in the line of vision is perceived as Floaters. Even normal vitreous may contain some opacities which are perceived as floaters. During PVD, the debris generated in the vitreous may lead to sudden increase in floaters. Also sometimes, during the separation a blood vessel of the retina may rupture with or without retinal tear and can cause vitreous hemorrhage (bleeding in the vitreous) which is perceived as shower of floaters. Large hemorrhages can cause large dark blobs in the visual field or an overall decrease in vision.

What to do once Flashes or Floaters are noticed?
If you have symptoms of a PVD (floaters, flashes, shower of spots or gray areas approaching from the side) it is importantto have a prompt and thorough examination of the retina so a search can be made for any retinal break or other pathology. Fortunately the great majority of PVDs do not cause a retinal tear and not all tears will lead to detachment.

How is retinal break or tear treated?
A retinal break or tear can be treated by a simple preventive procedure of Laser or Cryopexy, as an outpatient procedure. These procedures create an adhesion between the retina and the underlying tissue by forming a scar tissue. This scar tissue prevents the seepage of liquid vitreous under the retina and thus prevents retinal detachment. These preventive procedures are virtually harmless and are very effective (95%) in preventing the more serious retinal detachment.

What happens to the Flashes or Floaters?
Following a PVD, it is expected that the floaters and flashes slowly diminish over a 3 month period. Once it has been determined there is no underlying retinal tear or detachment, the floaters may be considered irritating but harmless. With time most floaters tend to become less bothersome and often disappear. If new floaters appear in future, they need to be examined again to determine if they are harmless or a symptom of the more serious retinal tear or detachment.

What are the warning symptoms for Retinal Detachment or Retinal Tear?

• Flashes
• Floaters, especially sudden onset
• Loss of field of vision
• Loss of central vision
• If one experiences any of these symptoms, he/she must consult an ophthalmologist, preferably a retinal surgeon immediately.

What to do if one has Retinal Detachment?
Once the retina detaches, it must be operated upon on an urgent basis to reattach the retina. If operated early, the results are generally quite good with significant gain in vision. A delay in surgery decreases the chances of success and the vision gained is also limited.

HYPERTENSION AND EYE

How can high blood pressure affect the eyes?
Hypertension or high blood pressure leads to many changes in the blood vessels of the body. These same changes in blood vessels affect the eyes in many ways.

It can cause the following problems in the eye:

• Hypertensive retinopathy
• Macroaneurysms
• Branch retinal vein occlusion (BRVO) and vitreous hemorrhage
• Optic nerve involvement (Optic neuropathy)
• Involvement of the nerves supplying the eye muscles, leading to temporary paralysis or weakness of these muscles

What are the symptoms of these conditions?
Many of these conditions may not have any symptoms in the initial stages. Therefore it is important to have a periodic eye checkup to detect these.

Branch retinal vein occlusion (BRVO) may lead to a blurring of vision especially for fine work. A vitreous hemorrhage may lead to a more severe loss of vision associated with a shower of red floaters.

Optic neuropathy may also lead to a loss of vision, which is painless and not associated with any floaters.

Paralysis or weakness of the muscles of the eye leads to restriction of movement of the eye and double vision.

What is the role of laser in treatment of eye disease because of high blood pressure?
Branch retinal vein occlusion (BRVO) is a condition that is commonly associated with high blood pressure and changes of hypertensive retinopathy.

This condition may lead to loss of vision by two mechanisms:

• Macular edema (swelling of the region of macula): Macula is the central region of the retina and is important for seeing fine details. A swelling in this region leads to a decrease in vision. This condition can be treated by doing laser therapy and intravitreal antiVEGF agents.
• Vitreous hemorrhage: Sometimes the BRVO may lead to formation of new vessels in the retina. These vessels are abnormal and are very fragile. These may bleed and may cause vitreous hemorrhage and thus loss of vision. A timely detection of these new vessels can be treated by doing laser therapy as well as injections of anti VEGF agents in the eye and thus causing these new vessels to disappear.

Macroaneurysm: This is an uncommon manifestation of hypertension. Untreated, this may cause bleeding into vitreous and thus loss of vision. This condition can be treated by laser therapy.

Why is eye checkup important if one has hypertension?
Eye is the only organ of the body where one can observe the blood vessels directly. Seeing the retina by using ophthalmoscope, we can see the blood vessels. Thus examination of the eyes help the physician or ophthalmologist to observe the changes in blood vessels because of hypertension. This gives an idea about the severity of the disease elsewhere in the body.

Moreover, presence of swelling of the disc (grade 4 hypertensive retinopathy) is an indicator of a very severe, life threatening rise in blood pressure, which warrants emergency treatment to control the blood pressure.

If the patient has both hypertension and diabetes, can both these diseases affect his/her eyes?
Yes. The patient can have changes of both diabetic retinopathy as well as hypertensive retinopathy. In fact, presence of hypertension may lead to exacerbation of the changes due to diabetic retinopathy. Therefore it is important to control the blood pressure in a patient with diabetic retinopathy.

AGE RELATED MACULAR DEGENERATION

The macula is the part of the retina, which provides us with central vision and allows us to see fine detail, such as recognizing a face, reading, or watching television. Macular Degeneration is a condition in which the macula gets damaged. It is often related to aging, and is commonly referred to as Age-related Macular Degeneration (AMD). The late stage, associated with vision loss, is the most common cause of irreversible blindness in people over the age of 50. It affects the central vision, especially while reading.

Most often vision loss starts in one eye. Because the healthy eye compensates for the loss of vision in the damaged eye, macular degeneration may initially go unnoticed. In many cases it will ultimately affect vision in the other eye as well.

What are the types of Age-related Macular Degeneration (AMD)?
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.

Why is Early Detection important?
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.

How is Macular Degeneration or AMD detected?
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.

What are the Treatments available?
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.

The detail fundus check up with dilation is also done by the Dr. Sachin V. Mahuli.

FOR MORE DETAILS YOU CAN CONTACT US AT  (0832) 2256788 , 2256188