Posterior Vitreous Detachment (PVD)

The eye is filled with a clear jelly substance called the vitreous. Light passes through the vitreous to focus on the retina, the inner lining of the eye. When the vitreous comes away from the retina this is called posterior vitreous detachment (PVD).

CAUSES:The vitreous is made from water and collagen and has a stiff, jelly like concistency. As we get older the vitreous becomes more watery and can not keep its usual shape. As a result it starts moving away from the retina.

SYMPTOMS of a vitreous detachment could be floaters, flashes of light and or a cobweb effect. If you experience any of these symptoms you need to have your eyes examined by an ophthalmologists within 24 hours because these may be an indication of a more serious problem such as a retinal tear or retinal detachment.

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Retinal Detachment and Retinal Tear

A retinal detachment is a very serious problem that usually causes blindness unless treated. The appearance of flashing lights, floating objects, or a gray curtain moving across the field of vision are all indications of a retinal detachment. If any of these occur, see Dr Mavrikakis right away. As one gets older, the vitreous (the clear, gel-like substance that fills the inside of the eye) tends to shrink slightly and take on a more watery consistency. Sometimes as the vitreous shrinks, it exerts enough force on the retina to make it tear.

Retinal tears can lead to a retinal detachment. Fluid vitreous, passing through the tear, lifts the retina off the back of the eye like wallpaper peeling off a wall. Laser surgery or cryotherapy (freezing) are often used to seal retinal tears and prevent detachment.

If the retina is detached, it must be reattached before sealing the retinal tear. There are three ways to repair retinal detachments. Pneumatic retinopexy involves injecting a special gas bubble into the eye that pushes on the retina to seal the tear. The scleral buckle procedure requires the fluid to be drained from under the retina before a flexible piece of silicone is sewn on the outer eye wall to give support to the tear while it heals. Vitrectomy surgery removes the vitreous gel from the eye, replacing it with a gas bubble, which is slowly replaced by the body’s fluids.

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Diabetic Retinopathy

Diabetics cannot use or store sugar properly due to lack of endogenous insulin. High blood sugar can damage the blood vessels of the retina (inner lining of the eye) and when they are damaged, they can leak fluid or bleed. This causes the retina to swell and form deposits leading to diabetic retinopathy.
In fact, the longer someone has diabetes, the more likely is to have diabetic retinopathy. Everyone who has diabetes is at risk for developing diabetic retinopathy, but not all diabetics do develop it.

Symptoms
In its early stages, patients may not notice any change in their vision, but it can lead to the later, sight-threatening form of the disease.

Sometimes difficulty reading or doing close work can indicate that fluid is collecting in the macula, the most light- sensitive part of the retina. This fluid build-up is called macular edema. Floaters can be a sign of diabetic retinopathy. Another sign is double vision, which occurs when the nerves controlling the eye muscles are affected.

If you experience any of these signs, you need to see a vitreoretinal specialist immediately. Otherwise, diabetics should see their retina specialist at least once a year for a dilated eye exam.

Types of Diabetic Retinopathy

Non proliferative Diabetic Retinopathy

This early stage of the disease is characterized by leakage of fluid, lipids and blood into the retina causing swelling and deposit formation

Proliferative Diabetic Retinopathy

In this later stage, new blood vessels grow on the surface of the retina. These new blood vessels can lead to serious vision problems because they can break and bleed into the vitreous (vitreous hemorrhage), the clear, jelly-like substance that fills the center of the eye. Proliferative retinopathy is a much more serious form of the disease and can lead to blindness.

Diabetic maculopathy
In some instances the leaking fluid accumulates at the macula, the area responsible for central vision and for recognizing numbers and letters. This is called diabetic macular edema and if not treated promptly may lead to blindness.

Important diagnostic tests in diabetic retinopathy

Fundus fluorescein Angiography
In this test, a yellow dye is injected into the body and then gradually appears within the retina due to blood flow. Special photographs of the retina are taken with the illuminated dye. Evaluating these pictures tells your retina specialist how far the disease has progressed.

Optical Coherence Tomography
This is a new test that uses light waves to provide cross sectional views of the retina without coming in contact with the eye. It is very important in diagnosis and follow up of diabetic patients with macular edema as it can evaluate disease progression

Ultrasound (B scan)
This is an important imaging test that allows evaluation of the retina in cases of vitreous hemorrhage where due to reduced fundus view the retina cannot be examined

Treatment of Diabetic Retinopathy

Pan Retinal Laser Photocoagulation (PRP)
This is the treatment of choice for the early stages of proliferative diabetic retinopathy as it reduces the oxygen demand to the retina by destroying peripheral oxygen – deprived retinal tissue. This has as a result the regression of the new blood vessels and prevention of vitreous hemorrhage.

Focal Laser or Grid Laser
This is the treatment of choice for diabetic patients with clinical significant macular edema (CSME) independent of their level of vision. Studies have shown that this treatment can prevent vision loss by 50%

Vitrectomy
This is the treatment of choice for diabetics with advanced proliferative diabetic retinopathy complicated with vitreous hemorrhage, tractional retinal detachment or iris rubeosis. During vitrectomy the vitreoretinal surgeon removes the vitreous from the eye and replaces it with saline.

Prevention of diabetic retinopathy
Fortunately, the risk of developing diabetic retinopathy can be significantly reduced by using common sense and taking good care of yourself.

• Keep your blood sugar under good control.
• Monitor your blood pressure and keep it under good control, or seek appropriate care.
• Maintain a healthy diet.
• Exercise regularly.
• Avoid smoking
• Keep regular follow up with your retina specialist

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RETINA VASCULAR DISEASES

Branch retina vein occlusion (BRVO)

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Central retina vein occlusion (CRVO)

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Branch retina artery occlusion (BRAO)

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Central retina artery occlusion (CRAO)

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Age Related Macular Degenaration

Dry and Wet forms of Age Related Macular Degeneration

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Dry Age Related Macular Degeneration

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Wet Macular Degeneration

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Treatment of Wet Macular Degeneration
While no current macular degeneration treatment is likely to completely restore vision lost to the eye disease, some drugs — such as Lucentis — may be able to preserve or even improve remaining vision. Lucentis (Ranibizumab). Approved by the FDA in June 2006 for treating the more advanced or "wet" form of macular degeneration. Lucentis is administered through monthly injections into the eye.

Lucentis (Ranibizumab) works by inhibiting proteins called vascular endothelial growth factor (VEGF), which stimulates the growth of new blood vessels in the body. VEGF is thought to contribute to development of macular degeneration by promoting the growth of abnormal blood vessels in the back of the eye (retina).

Avastin (Bevacizumab) An unapproved form of Lucentis, is considerably less expensive and appears to produce similar results in macular degeneration treatment. Avastin is administered through monthly injections into the eye.

The Lucentis vs. Avastin debate continues while an ongoing clinical trial compares outcomes and safety of the two treatments.

Visudyne drug treatment (Photodynamic Therapy or PDT). Visudyne was the first drug therapy approved for treatment of the wet form of macular degeneration. It is only for those patients who have new blood vessel growth (neovascularization) under the retina in a well defined, distinctive pattern known as "predominantly classic."
In this treatment procedure, the doctor injects Visudyne into your arm, then activates the drug as it passes through the retinal blood vessels by shining a low-energy laser beam into your eye. Visudyne is activated by the laser light, which produces a chemical reaction that destroys abnormal blood vessels.
Visudyne sometimes is used in addition to Lucentis or Avastin as a treatment for wet macular degeneration.
Laser treatment. Laser photocoagulation is another treatment for wet Age Macular Degeneration. The procedure uses laser light to destroy or seal off new blood vessels to prevent leakage.

A major drawback of laser photocoagulation, however, is that it produces many small retinal scars, which are perceived as blind spots by the patient. For this reason, the laser procedure is no longer widely used to treat AMD.

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Macular diseases

Macular hole

The macula is the part of the retina responsible for acute central vision, the vision you use for reading, watching television, and recognizing faces. A macular hole is a small, round opening in the macula. The hole causes a blind spot or blurred area directly in the center of your vision.

Most macular holes occur in the elderly. When the vitreous (the gel-like substance inside the eye) ages and shrinks, it can pull on the thin tissue of the macula, causing a tear that can eventually form a small hole. Sometimes injury or long-term swelling can cause a macular hole. No specific medical problem is known to cause macular holes. Vitrectomy surgery is the only treatment for a macular hole. During vitrectomy Dr Mavrikakis removes the vitreous gel and scar tissue pulling on the macula and keeping the hole open. The eye is then filled with a special gas bubble to push against the macula and close the hole. The gas bubble will gradually dissolve, but the patient must maintain a face- down position for one to two weeks to keep the gas bubble in contact with the macula. Success of the surgery often depends on how well the position is maintained.

The gas bubble gradually goes away over time, and natural eye fluids take its place while the hole is healing.If you have had surgery for a macular hole using a gas bubble, you won't be able to travel by air for several weeks, because the gas can expand with pressure changes, causing eye damage.With treatment, most macular holes shrink, and some or most of the lost central vision can slowly return. The amount of visual improvement typically depends on the length of time the hole was present. People who have had a macular hole in one eye have a higher chance (about 10 percent) of developing a macular hole in their other eye at some time in their life. Therefore, you should have regular eye exams as determined by your eye doctor to catch problems early.

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Epiretinal membrane

The retina is a layer of light-sensing cells lining the back of your eye. As light rays enter your eye, the retina converts the rays into signals that are sent through the optic nerve to your brain, where they are recognized as images.

The macula is the small area at the center of your retina that allows you to see fine details. The macula normally lies flat against the back of the eye, like film lining the back of a camera. As you age, the clear, gel-like substance that fills the middle of your eye begins to shrink and pull away from the retina. In some cases, a thin “scar tissue” or membrane can grow on the surface of the macula. When wrinkles, creases, or bulges form on the macula due to this scar tissue, this is known as an epiretinal membrane or macular pucker. Damage to your macula causes blurred central vision, making it difficult to perform tasks such as reading small print or threading a needle. Peripheral (side) vision is not affected.

Symptoms, which can be mild or severe and affect one or both eyes, may include:

• blurred detail vision;

• distorted or wavy vision;

• gray or cloudy area in central vision; and

• blind spot in central vision.

If your symptoms are mild, no treatment may be necessary. Updating your eyeglass prescription or wearing bifocals may improve your vision sufficiently. If you have more severe symptoms that interfere with your daily routine, Dr Mavrikakis may recommend vitrectomy surgery to peel and remove the abnormal scar tissue. During this procedure, Dr Mavrikakis uses tiny instruments to remove the wrinkled tissue.
After the ERM peeling, vision should improve gradually, though it may take up to three to six months for the best visual results.

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Central serous retinopathy

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Macular edema

Macular edema is the swelling of the macula, the small area of the retina responsible for central vision. The edema is caused by fluid leaking from retinal blood vessels. Central vision, used for reading and other close, detail work, is affected.

Because the macula is surrounded by many tiny blood vessels, anything that affects them, such as a medical condition affecting blood vessels elsewhere in the body or an abnormal condition originating in the eye, can cause macular edema. Retinal blood vessel occlusion, eye inflammation, diabetes and age-related macular degeneration have all been associated with macular edema. The macula may also be affected by swelling following cataract extraction, although typically this resolves itself naturally.

The most common symptom of macular edema is blurred or distorted vision.

Treatment seeks to remedy the underlying cause of the edema. Eyedrops, injections of steroids or other, newer medicines in or around the eye, or laser surgery can be used to treat macular edema. Recovery depends on the severity of the condition causing the edema.

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Trauma

Intraocular Foreign Bodies and Sharp Trauma

Sports Eye Injuries

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Management of complications of cataract surgery

Cataract surgery is extremely safe and effective. However occasionally complications occur and it is the skills of the vitreoretinal surgeon which are called to remedy the situation. It is important to realize that these complications are rare but the vitreoretinal surgeon encounters them from time to time due to the high volume of cataract operations being performed.

Rarely the cataract surgeon will drop fragments of the cataract into the back of the eye. These must be removed by vitrectomy surgery to restore the vision.
Bacteria can enter the eye during the operation and cause infection inside the eye (endophthalmitis). This must be treated by injection of antibiotic into the eye and sometimes vitrectomy.

The risk of retinal detachment is slightly increased after cataract surgery. If you experience increased floaters or flashing lights after cataract surgery you must have your retina examined as soon as possible to rule out retinal detachment.

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