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Vitreo-Retinal Services |
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| Which parts of the eye are the Retina and Vitreous? |
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 The eye is like a camera with a lens in front and a film (retina) at the back. The cornea and lens in the front of the eye focus the rays of light onto the retina which then converts the image into electrical signals that are sent to the brain through the optic nerve.
The retina is a thin sheet of tissue which lines 2/3rds of the back of the eye. Fibers from all over the retina join to form the optic nerve which is in the centre of the retina. A little to one side of the optic nerve is the main part of the retina called the macula. The macula is a very small area but is responsible for the detailed, central vision that we have (i.e. reading, writing, recognizing faces, seeing the watch, mobile numbers etc). The rest of the retina gives us peripheral vision essential for walking and driving.
A photograph of the central retina showing the optic nerve head (disc), macula and the major blood vessels.
The vitreous is the clear jelly like substance that fills the eye- from the lens in the front to the retina at the back. Its function is not well defined. With age it undergoes degeneration, liquefies and shrinks in size. As it occupies less space it cannot fill the entire eye and detaches from the retina posteriorly.
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| What are common Vitreo-Retinal diseases? |
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The common Vitreo-retinal diseases seen are:
- Diabetic Retinopathy
- Occlusions of the Retinal Veins
- Age Related Macular Degeneration
- Retinal Detachment
- Myopic Retinal Degeneration
- Floaters/Posterior Vitreous Detachment
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| What is Diabetic Retinopathy? |
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Diabetic retinopathy (DR) is a disorder of the small blood vessels of the retina (angiopathy) as a result of prolonged high blood sugars. It is part of the angiopathy occurring in the entire body that results in the other complications of diabetes such as kidney problems (nephropathy), nerve problems (neuropathy) and several others. When severe it can result in blindness.
The diseased blood vessels are not able to function well and either ’leak’ blood substances into the retina or get ‘blocked’ resulting in ischemia (lack of blood supply) to parts of the retina.
Leak of blood constituents causes swelling of the retina (arrow), retinal hemorrhages (arrows) and deposition of fats (arrows). These leaks are usually at the macula and result in blurred vision.
When the blood vessels get blocked the ischemic retina liberates chemicals that cause the growth of new vessels. These vessels however do not supply the ischemic retina but grow on its surface. They may grow around the ischemic retina or when there is widespread ischemia they grow on the optic nerve. These blood vessels are very fragile and tend to bleed easily. This can cause a sudden loss of vision as the eye fills up with blood (vitreous hemorrhage). In more advanced cases blood vessels can grow in the front part of the eye causing a severe form of glaucoma (called neovascular glaucoma) which can be extremely painful.
The blood vessels are associated with fibrous tissue which can contract. This, then pulls the retina leading to a retinal detachment.
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| When should I get my eyes examined? |
All diabetics must undergo a thorough eye examination once a year.
| Age of onset |
Recommended time of First examination |
Minimum follow up |
| 0-30 years |
After 5 years/attainment of puberty-whichever is earlier |
Once a year |
| Above 30 years |
At time of diagnosis |
Once a year |
| Pregnancy |
Prior to pregnancy/First trimester |
Every trimester |
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| Do I need to get myself examined even if I have perfect vision? |
Yes, all diabetics must be examined even if they have perfect vision as there can be a Diabetic Retinopathy without loss of vision. Also it is easier to prevent loss of vision rather than to restore it.
The examination must include a check of the vision, eye pressures and examination of the retina after dilation with eye drops.
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| What Investigations may be required? |
The following investigations may be ordered by your doctor to understand your disease better and to plan the treatment.
- Fluorescein Angiography(FFA)
- Optical Coherence Tomography (OCT)
- Ultrasonography (USG) in patients with vitreous hemorrhage.
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| What are the treatment options? |
Depending on the type of retinopathy that you have the following treatment options may be recommended. One or more may be advised at the same time.
- Laser Therapy
- Injections of drugs into the eye
Bevacizumab (Avastin)
Ranibizumab (Lucentis)
Pegaptanib Sodium (Macugen)
Triamcinolone (Tricort/Kenacort)
- Vitreoretinal Surgery
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| Is the treatment of diabetic retinopathy required again and again? |
| Yes. Since the disease is never ending the retinopathy can recur. All patients need regular follow up throughout their lives. Further investigations and treatment are required from time to time as decided by the doctor. |
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| Age Related Macular Degeneration (ARMD) |
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| Retinal Vein Occlusion |
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| Floaters/Posterior Vitreous Detachment (PVD) |
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| Floaters |
| Floaters are opacities that appear and ‘float’ about in the field of vision. They are of myriad shapes and are often described as ‘cob webs’ ‘flies or mosquitoes’. When the eye is moved the floaters move too. They are better visible against a white background or sunlight. They are due to opacities within the clear vitreous jelly. Most commonly they are because of ‘muscae volitantes’ found in normal people especially myopes (short sighted). They are also often due to posterior vitreous detachment (see below). Other causes are vitreous hemorrhage, inflammations. |
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| Posterior Vitreous Detachment (PVD) |
 The back of the eye is filled with a jelly like substance called vitreous. This is normally transparent. A natural ageing process causes the vitreous shrink and collapse in some individuals. When this occurs it is usually quite sudden causing ‘floaters’ or ‘cobwebs’ to appear in the vision. The patient will often notice an associated flashing light at the side of the vision. The light may be quite dim so that it is seen most easily in the dusk or dark. Some patients do not notice the flashing light.
When the vitreous has separated from the retina it is known as a posterior vitreous detachment.
 A large ‘floater’ in the vitreous cavity due to posterior vitreous detachment (PVD) |
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| Will it affect my vision? |
| The floater can be annoying but they are harmless. They usually persist but become less noticeable with time as they sink within the eye under gravity and move further away from the retina. The flashing light will usually subside over 4 to 12 weeks, but in some patients it may take a little longer. |
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| What shall I do if I start seeing floaters? |
| You should be have your retina examined after dilating the pupils because in some patients a PVD may cause a little tear in the retina which can then progress to a retinal detachment. Also sometimes a floater can be because of hemorrhage. |
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| Retinal Detachment |
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| What is a Retinal Detachment? |
Retinal Detachment is a condition where the retina separates from its proper position at the back of the eye. In most cases this is because a hole or tear has formed in the retina allowing the fluid to pass behind the retina.
 Superior half of the retina |
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| What are the Symptoms? |
| Most commonly, a patient with retinal detachment presents with a sudden, painless loss of vision like a curtain rising or falling in front of the eye. It may be preceded by floaters and flashes. |
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| How is it Treated? |
| A retinal detachment is treated surgically. The aim of surgery is to repair the tear(s) using biological ‘adhesive’ in the form of cryotherapy or laser. The ‘biological glue’ takes several weeks to be effective so some form of splint is required to help the retina during this critical period. |
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| Varieties of Splint |
External Splint or Scleral Buckling
In many patients the tear in the retina can be repaired using a piece of silicone sewn directly to the wall of the back of the eye producing an indent or ‘buckle’. This maintains closure of the retinal tear as healing takes place. |
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Internal Splint or Vitrectomy
In some patients, closure of the retinal tears using an external approach is not possible or appropriate. Using ‘key-hole’ instruments, the vitreous gel filling the space in front of the retina is replaced with gas or silicone oil which seal the retinal tears from the inside. If a gas is used it slowly disappears over the weeks following surgery. If the silicone oil splint is required then a second operation (Stage II) may be planned to remove the silicone oil once the retina is stable. |
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Mixed
In some patients a combination of internal and external splints are required. |
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Post Operative Posturing
If an ‘internal’ splint of gas or silicone oil is used, you may be asked to posture in the early postoperative period so that your head is in a particular position. This allows the internal splint to float and support that particular part of the retina which was torn. You will be given instructions regarding the posturing position (if required) after your operation. Although it is perfectly safe to move, walk, visit the bathroom, have a meal etc, it is helpful if the posturing can be continued at home after your discharge for approximately 10 days. |
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| Fundus Fluorescein Angiography (FFA) |
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| What is Fundus Fluorescein Angiography (FFA) |
Fluorescein angiography is a diagnostic procedure which uses a special camera to take a series of photographs of the retina. A special water-soluble fluorescein dye is injected into a vein in the arm. The dye travels through the veins and into the arteries as it circulates throughout the body. As the dye passes through the blood vessels of the retina, the special camera flashes a blue light into the eye and takes multiple photographs of the retina. If the blood vessels are abnormal, the dye may leak into the retina. If there is damage to the lining underneath the retina, or the appearance of abnormal new blood vessels growing beneath the retina, their precise location will be revealed. Ischemic areas will show an absence of dye.
 Fluorescein angiography being performed
 FFA of a patient with diabetic retinopathy showing fuzzy white leaks of dye from new vessels |
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| Why is FFA done? |
- To help the doctor confirm a diagnosis.
- To provide guidelines for treatment.
- To keep a permanent record of the vessels at the back of the eye
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| What is the Procedure? |
- Your pupils will be dilated with eye drops.
- An injection of yellow dye is given into a vein in your arm.
- A series of photographs is taken as the dye enters the eye.
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| What are the special instructions? |
| It is best not to eat something 2 hours before the test. All medications must be taken as usual. The procedure can be performed even of the sugars are not controlled. As the pupils will be dilated you may have blurred vision for 3-4 hours and may need to arrange your schedule and arrange for a driver. |
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| What are the Risks? |
| After the fluorescein dye is injected, your skin may turn yellowish for several hours. This color disappears as the kidneys filter the dye from your body. Because the dye is removed by the kidneys, your urine will turn dark orange for up to 24 hours following fluorescein angiography. Some individuals may experience slight nausea during the procedure, but this usually passes within a few seconds. If the dye leaks out of a fragile vein during the injection, some localized burning and yellow staining of the skin may occur. This burning usually lasts only a few minutes and the staining will go away in a few days. Allergic reactions to fluorescein dye are rare. If they occur, they may cause a skin rash and itching. This is usually treated with oral or injectable antihistamines/steroids, depending on the severity of the symptoms. Even more rarely, severe allergic reactions (anaphylaxis) can occur and be life threatening. Please notify the doctor if you have a tendency of allergies. FFA must be avoided in pregnant women and those with severe allergy to the dye. |
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| Optical Coherence Tomography (OCT)? |
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| Ultrasonography (USG)/(B Scan)? |
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| What is Ultrasonography (USG)/(B Scan)? |
It is a test performed when the inner parts of the eye are not visible due to opacities such as a dense cataract, vitreous hemorrhage. Ophthalmic ultrasonography uses high-frequency sound waves, which are transmitted from a probe into the eye. As the sound waves strike intraocular structures, they are reflected back to the probe and converted into an electric signal. The signal is subsequently reconstructed as an image on a monitor, which can be used to make a dynamic evaluation of the eye or can be photographed to document pathology.
B-scan ultrasonography is most useful when direct visualization of intraocular structures is difficult or impossible. It tells us about the state of the vitreous. The ultrasound can detect retinal detachment, traction on the retina, retinal tears and tumors. It can be used to study the choroid to look for choroidal thickening, choroidal detachment and masses and the optic nerve for swelling or gross glaucomatous cupping.
In some situations ultrasound is used even when the pathology is visible as it highlights the intrinsic features of the lesion. These are in case of retinal and choroidal tumors, to differentiate types of choroidal detachments, to look for choroidal thickening in uveitis, differentiate different types of retinal detachment, disc drusens, osteomas and others.
Ultrasonography is also useful for orbital lesions and is used to look for orbital tumors, cysticercus, and foreign bodies. It is used to measure the thickness of the ocular muscles in thyroid eye disease.
 USG being performed
 USG image showing choroidal detachment |
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| How is USG performed? |
| The procedure does not need any preparation. An USG probe is placed on the eye after some jelly has been put. The procedure takes a few minutes and the results are immediately seen. |
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| Laser Therapy |
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| What is a Laser? |
| A laser is an instrument that produces a pure, high-intensity beam of light energy. The laser light can be focused onto the retina, selectively treating the desired area while leaving the surrounding tissues untouched. The absorbed energy creates a microscopic spot to destroy lesions or weld tissues together. It is usually advised for diabetic retinopathy, retinal vein occlusions, retinal tears and holes. |
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| What happens during laser treatment? |
Laser therapy is not a surgery. There are no special preparations before eye laser treatment. You should eat normally and take your regularly prescribed medications before surgery.
Retinal laser surgery is performed in the OPD. Eye drops will be given to dilate the pupil and numb the eye. The treatment is performed while you are seated in a chair, similar to the one used for regular eye examinations. You will remain awake and comfortable. Treatment is usually painless, although rarely some patients may require a numbing injection for discomfort or sensitivity to the laser light.
The laser treatment usually takes 5-30 minutes to complete, and you can go home immediately following surgery. Arrangements for transportation should be made in advance since you may not be able to drive right away.
 Fresh laser spots seen in a part of the retina |
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| What are the restrictions and side effects after laser? |
There are virtually no restrictions following retinal laser surgery, and you should be able to resume your normal activities and work schedule the following day.
Most patients notice no vision changes following their laser surgery, although there may be some temporary blurring for several weeks to months. In addition, depending on the condition being treated, some may notice a permanent blind spot or decrease in peripheral and night vision.
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| What are the post laser instructions? |
| You can eat, drink and move about as you did before the laser. You can watch television and use the computer immediately when the vision returns after the effects of dilation ends. |
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| Will I need more than one laser treatment? |
| It will take several weeks to months before we can tell whether the laser surgery has been successful. Many patients, however, will need more than one treatment to control their eye problem and prevent further loss of vision. |
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| Intraocular Injections |
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| Why are Intraocular Injections given? |
| Intraocular injections are used to deliver a high dose of medicine into the eye to treat retinal diseases. They may be given to dry up new vessels so that they do not bleed. They may be given to decrease swelling of the macula. Hence they are commonly given for diabetic retinopathy, age related macular degeneration, retinal vein occlusions, macular edema, uveitis, retinitis. |
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| Which injections are given? |
| The commonly given injections are Bevacizumab (Avastin), Ranibizumab (Lucentis), Pegaptanib sodium (Macugen) and Triamcinolone (Tricort/Kenacort), Ganciclovir, Cidofovir. |
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| What is the procedure and does the injection hurt? |
The injections are given in the operation theatre after preparing the eye like for other eye surgeries. It is best to have the blood sugars and blood pressure well controlled before the injection. Blood thinning medication does not need to be stopped. The pupils are dilated and numbing drops are put. The injection is given using the operating microscope. A very fine needle is used and hence there is little discomfort. The entire procedure takes a few minutes. The eye is patched for a few hours and if triamcinolone has been injected it is advised to remain seated for 4 hours after the injection and not to lie flat.
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| What are the possible side effects? |
| The side effects are minimal. There can be a small hemorrhage at the site of injection which clears up in a few days. You may see some floaters that may be due to seeing the drug itself or on seeing an air bubble that may have been injected. They will disappear after some time. Mild pain may be there but significant pain must be reported to the doctor and could result from an abrasion of the cornea, rise in the eye pressure or rarely due to an infection. |
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| How do I prepare for the procedure? |
- Make sure you understand the indication along with the potential risks of the procedure
- Do not wear eye makeup on the day of the procedure
- Do not wear eye makeup on the day of the procedure
- Notify your doctor of any infection or inflammation in or around your eyes or if you have a cold or flu
- Notify your doctor if you have allergies to iodine or xylocaine
- Arrange for someone to drive you to and from your appointment
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| Do injections need to be repeated? |
| The effect of the commonly injected medications lasts for 1-3 months. If the disease needs further management then the medication needs to be injected again. It is common for these injections to be given several times. |
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Patient Information
INSTRUCTIONS FOLLOWING VITREORETINAL SURGERY |
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| Will I have pain? |
| Some discomfort is normal and expected following surgery. The first few days after surgery you may need to use prescription pain pills. If the pain worsens, call the doctor. |
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| Do I need to wear sunglasses? |
| You do not need to wear sunglasses at home. However, you may be more comfortable wearing a patch outside in the sun or in a dusty, windy environment. You can put an eye patch when sleeping or napping in the first 4-5 days. |
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| How do I clean my eyes? |
| You may expect a moderate amount of drainage for a week. Gradually, the drainage should decrease. The lids can be cleaned with surgical cotton wool boiled for 10 minutes. Wipe the eyelids gently from the nose outward. |
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| Will there be swelling? |
| Some swelling is normal for about a week after which it will gradually decrease. Applying a cool compress, using a clean washcloth, for 5-10 minutes several times a day may reduce the swelling and make you more comfortable. |
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| Will I need to use eye drops? |
You will be given several different kinds of eye drops or ointment when you leave the hospital. The directions will be on each bottle. You will be using drops from four to eight weeks. Bring all eye medications (drops, ointments, or pills) with you to each visit.
Always wash your hands before putting in the eye drops. You may wish to have someone else help you. Pull down on the lower lid and squeeze one drop from the bottle, being careful not to touch the dropper to your eye or eyelid. One drop is sufficient, but another may be used if the first did not go into the eye. It is often easier to put in the drops if you are reclining or lying down. Wait 2-5 minutes after the first drop before using the second drop to allow the medications to absorb into the eye. |
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| How long will it take for my vision to improve? |
| Your vision should gradually improve, but it may take up to six months to regain your best vision. Frequently, air or gas bubbles are injected into the eye at the time of surgery. This will blur your vision significantly at first. As the bubble becomes smaller it will cause a black line in your vision that moves as you move your head. As the bubble becomes smaller you may notice that it looks more like a bubble or that it will break up. |
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| Post operative posturing |
| If an ‘internal’ splint of gas or silicone oil is used, you may be asked to posture in the early postoperative period so that your head is in a particular position. This allows the internal splint to float and support that particular part of the retina which was torn. You will be given instructions regarding the posturing position (if required) after your operation. Although it is perfectly safe to move, walk, visit the bathroom, have a meal etc, it is helpful if the posturing can be continued at home after your discharge for approximately 10 days. |
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