Retinal and vitreous problems may be an important cause of vision or even blindness. In some cases, surgery may be beneficial when performed at the right time in order to prevent a significant visual loss.

The retina consists of two parts: the peripheral retina and the macula. If you imagine the retina as a circle with a target in the center, the macula is the target. Although it is very small in size, the macula is responsible for 90% of the eye’s ability to discriminate. The larger retinal area surrounding the macula, which accounts for 95% of its surface, is called peripheral retina. This zone provides the so-called “peripheral” or lateral vision and it is the portion of the retina that acts when we see an object located outside the point of central focusing.

Since the peripheral retina is unable to see sharp details, it cannot be used for reading, threading a needle, driving or recognizing a face. We can tell who is sitting by our side because we recognize the person’s silhouette, but we cannot see the person’s facial expression.

The vitreous is very similar to the egg white and is the substance that fills the central cavity of the eye. The vitreous is attached to the retina, mainly in the posterior portion of the eye, to the optic nerve, the macula and the large retinal vessels.

The retina may suffer a wide variety of diseases, some of which are very complex. An adequate diagnosis is the key to design a treatment plan that may stop the progression or cure the disease in order to preserve as much vision as possible.

People with retinal disease experience a wide range of symptoms including light flashes, muscae volantantes, loss of peripheral vision, and even blindness.

Many retinal diseases are associated with underlying conditions, prior ocular trauma or family history. In order to arrive at the correct diagnosis, the ophthalmologist performs a complete eye examination with a dilated pupil, followed in some cases by paraclinical tests designed to confirm the diagnosis or determine the extent of the existing damage.

The primary treatment goal is to preserve vision and reduce the rate of progression of the disease. All possible options must be analyzed on the basis of each individual case.

Why is a retinal detachment considered a serious problem?

When there is a retinal tear, the fluid found in the vitreous cavity may go through the tear and pool under the retina. Slowly, the vitreous fluid settles behind the retina, separating it from the posterior wall of the eye. This separation is called retinal detachment and vision is lost where the detachment occurs.

Considering that the majority of tears occur at the peripheral retina or lateral portion of the retina, the detachment initially causes a loss of lateral or peripheral vision. The patient may perceive a dark shadow or a veil coming from the side, from above or from below. In most cases, after a retinal detachment starts, the entire retina will eventually detach and the eye will lose all of its useful vision.

Who can suffer a retinal detachment?

Some people are more prone than others of suffering a retinal detachment.

• High myopic patients.
• Patients with a family history of detachment.
• Patients who have already had a retinal detachment in one eye.
• Patients with retinal thinning (“reticular degeneration”) or other degenerative changes.
• Patients previously subjected to cataract surgery have a 1-2% probability of developing a retinal detachment.

All people who belong to one of these risk groups should be checked regularly and receive immediate care in the event of sudden light flashes, new muscae volantantes or loss of peripheral vision.

What are the treatment options available?

There are several treatment options. When there is a retinal tear without detachment, photocoagulation (small laser burns) or cryopexy (freezing of small areas) are an option to keep the retina attached and prevent detachment.

When there is a tear plus detachment, the situation if more complex and requires surgical treatments using techniques such as scleral banding, pneumatic retinopexy or vitrectomy.

Diabetic retinopaty is the primary cause of blindness in the Unites States and one of the most important in our country. Twenty-five per cent of all diabetic patients have some for of retinopathy and only 10% do not suffer from it during their lifetime.

Why does diabetic retinopathy occur?

High blood sugar (glucose) levels like those produced in diabetes damage the vascular endothelium (an important component of the blood vesel walls), affecting the entire circulatory system, including the retinal vessels.

How can diabetic retinopathy result in blindness?

The retina is the most important part of the eye. It is there that light is converted into electrical impulses that can be interpreted by the brain. Diabetes may lead to retinal dysfunction mainly as a result of three things:

1. Macular edema or abnormal pooling of fluid between the fine layers of the retina at the macula (the most sensitive point in the retina). Macular thickening prevents its adequate functioning. The fluid accumulation results from the altered function of the blood vessels because of diabetes.

2. Vitreous hemorrhage: In more advanced phases or diabetic retinopathy, new vessels prone to break easily form in the eye. When they break, they release blood into the eye, preventing light from reaching the retina.

3. Retinal detachment: Also during the advanced phases of the disease, the retina may detach mainly due to the traction exerted by the vitreous and the new vessels. When it detaches, the retina loses its source of nutrients and, therefore, its function.

What are the grades of diabetic retinopathy?

1. Non-Proliferating Diabetic Retinopathy (NPDR): In healthy individuals, retinal blood vessels only by permitting the outflow of nutrients and oxygen towards the retina (not of fluid or plasma). In people with diabetic retinopathy, the content of the vessels (blood and plasma) flow out abnormally because of the injury to the blood vessel walls caused by high sugar levels. This accumulation of fluid impairs retinal function.

2. Proliferating Diabetic Retinopathy (PDR): Because of the continuous injury to the blood vessels as a result of high glucose levels, many of them finally shut down preventing blood and nutrients from reaching the retina. Those deprived areas of the retina attempt to obtain oxygen and nutrients by producing new blood vessels. Unfortunately, these new vessels (neovessels) do not function normally and they grow not only in the retina but also into the vitreous (towards the middle of the eye, where no blood vessels should be present). These new vessels may bleed and produce vitreous hemorrhage or pull the retina until it detaches.

Which factors increase the risk of developing diabetic retinopathy?

Blood sugar levels: High glucose levels significantly increase the risk of the onset or progression of retinopathy.

Time course of the diabetes: For Type I diabetics (Insulin-dependent or juvenile diabetes mellitus), the onset of diabetic retinopathy is usually five years after the initial diagnosis. For Type II diabetics (non-insulin-dependent diabetes mellitus and the most common form of the disease) the onset of retinopathy is usually 10 years after the initial diagnosis. (It is worth considering that, in many cases, there is a late diagnosis and, therefore, retinopathy manifests itself earlier on.)

Pregnancy: Pregnancy increases the risk of NPDR and accelerates its progression in the event it is already present.

Race: Diabetic retinopathy is more frequent among blacks.

Dislipidemia: The risk of diabetic retinopathy increases with high LDL cholesterol levels.

What are the symptoms of diabetic retinopathy?

Initial symptoms include:

Reduced night vision.

Slow recovery of vision after bright light exposure.

Abnormalities in color vision (mainly blue and yellow).

It is important to not that in order for symptoms to appear, the disease must be in an advanced stage and treatment is not as effective. Hence the importance of controlling retinopathy before the onset of symptoms.

What are care considerations with this disease?

The most important care consideration when the diagnosis of retinopathy is made is to control blood glucose levels. It is important to visit an endocrinologist and an ophthalmologist who will determine the kind of treatment required and request any additional tests. Fluoresceine angiography of the retina will be required periodically in order to observe blood vessel function.

What is the treatment for diabetic retinopathy?

Treatment depends on the stage of the disease. Laser photocoagulation may be used during the initial stages. In more advance stages, a surgical procedure such as vitrectomy is required in order to correct vitreous hemorrhages or retinal detachments.

In most cases, the goal of treatment is to stop the progression of the disease. There are only a few cases in which there is a dramatic improvement. That is why the ideal treatment is prevention in order not to reach advanced stages of the disease. The most important factor in prevention is the adequate control of blood sugar levels.

Do not allow you or a loved one to become blind because of inadequate control of blood sugar levels.

What is the macula?

The macula is that part of the eye that is responsible for central vision and that enables us to see fine details. This is the vision that we need in order to drive, recognize people’s faces and see from near.

What is macular degeneration?

It is the most frequent cause of vision loss after 60 years of age in the Western world. As we age, the macula may begin to degenerate as a result of several factors related to nutrition and blood circulation among others. There are other forms of macular degeneration that may affect young or middle-aged people, in particular myopes.

What are the symptoms of macular degeneration?

The most characteristic symptoms include blurred vision, progressive difficulty for reading, distorted sizes and shapes where straight lines appear wavy, appearance of dark spots in the central visual field that are visible in particular when reading small print. In the long run, macular degeneration affects only central vision and does not cause total blindness. After fifty years of age it is known as age-related macular degeneration.

What is the treatment for age-related macular degeneration?

Treatment is dependent on the type of macular degeneration and the degree of involvement. For the dry type ARMD there is no treatment that can improve vision, and only therapy with multiple vitamins has show to reduce the rate of progression of the disease.

Photodynamic Therapy is an innovative form of treatment used in referral centers for the wet type of ARMD. It combines the use of a laser with an intravenous medication. In some selected cases, it has shown to stop the progression of the disease. That is why patients are requested to “come to a referral center as soon as they see wavy lines in a grid”. Since we have only one pair of eyes, it is important to look for the safety offered by a center with good experience in this form of treatment.

What are epiretinalmembranes and how are they treated?

Also known as macular pucker, these membranes are scar tissue formations on the macula. When they grow, they cause a pull effect, creating distorted and blurred vision. The most appropriate therapy is observation until vision becomes significantly altered. At that point, vitrectomy and peeling of the membranes is performed in order to release the traction.

What are macular holes and how are they treated?

The Macula is the retinal tissue responsible for central vision, and the vitreous is firmly attached to it. With age, the vitreous contracts, separating from the retina and in so doing it may lift the macula and even create holes in it. De novo holes are less frequent. Macular holes cause distortion and loss of central vision.

It is important to see an ophthalmologist at the slightest change in vision, because prognosis improves with early detection. The treatment for advanced cases is the surgical removal of the vitreous gel and the membrane that lines the hole (vitrectomy). This procedure requires introduction of intraocular gas.

How do arterial obstruction and venous thrombosis affect vision?

With the obstruction of the central retinal artery (the main artery of the retina) there is a severe vision loss that is irreversible in many cases.

Retinal venous occlusions are the second most significant vascular disease affecting the retina after diabetes mellitus, and it appears usually in people over 60. In many cases there is a significant loss of vision in the affected eye. The most common treatment is Argon laser photocoagulation. New techniques have been developed in recent years in an attempt to improve vision.

What is uveitis?

Uveitis is the term used to designate the inflammation of the uvea (one of the layers of the eye that lies between the retina and the sclera. The uvea contains many blood vessels that supply nutrients to the eye. Uveal inflammation may affect the cornea, the retina, the sclera and other vital ocular components, affecting vision.

There are many causes of uveitis: it may occur as a result of surgery, trauma, viral infections (egg. Herpes, measles, rubella), fungal infections (e.g. Hystoplasmosis) or parasites (like toxoplasmosis), although in most cases the cause remains unknown.

Uveitis may be associated with autoimmune conditions or even a severe inflammation in one eye may cause a severe inflammation of the other eye (sympathetic ophthalmia).

What are the symptoms of uveitis?

Inflammation may produce pain of varying degree, blurred vision, red eye, muscae volantantes and hypersensitivity to light.

How is uveitis diagnosed?

The diagnosis is made with a routine clinical examination. However, in order to determine the cause, several additional paraclinical test and diagnostic methods may be required. The condition is treated with anti-inflammatory agents and immunomodulators in the form of eye drops, injections or tablets, with the subsequent treatment of the underlying cause.

What is retinopathy of prematurity?

Retinopathy of prematurity (ROP) is the most important cause of blindness in childhood in developed countries. Multidisciplinary monitoring is required in order to ensure detection and early treatment.

Pre-term babies or low birth weight babies usually require oxygen to help the immature lungs to develop. The exposure to high oxygen levels during long periods of time may promote the proliferation and disorganized growth of small vessels that produce scars. In some children, the retina is capable of recovering with small residual damage, but other cases progress to retinal detachment and blindness.

What is the treatment for retinopathy of prematurity?

Early detection is of paramount importance in order to institute an effective therapy for the baby who has been exposed to high oxygen levels as a way to preserve its life. Once the disease is identified, treatment varies according to the degree of severity, ranging from observation to laser photocoagulation and vitrectomy.

What is a retinoblastoma?

Retinoblastoma (RB) is a rare form of cancer affecting the photosensitive cells of the retina. Although it is rare, it is the most frequent malignancy in children and the third most common form of cancer in children under 5.

There are two types of retinoblastoma: The first is an inherited form that affects both eyes (10% of cases). The second form is not hereditary, it affects only one eye and it does not carry an increased risk for the development of a second tumor.

The first form carries a lifetime risk of developing other cancers due to the abnormal RB gene on chromosome 13 that is an important tumor suppressor gene. Genetic counseling is important in all these cases.

What are the treatment options for Retinoblastoma?

Early detection significantly improves therapeutic outcomes and the best preservation of vision because treatment depends on the size and location of the tumor. When untreated, the tumor forms nodules and grows rapidly extending through the eyeball into the orbit, finally causing death. Treatment depends on the stage and location of the disease and there are several options such as cryotherapy, transpupillary thermal treatment, brachitherapy and even surgical resection.

What is pigment retinosis?

Pigment retinosis (PR) is a group of diseases that tend to run in families and cause progressive retinal degeneration of both eyes. It starts as night blindness and progresses towards a loss of the peripheral visual field. Symptoms appear in the teenage years or in young adulthood, but they may occur at any age and progress over many years until there is tunnel vision or total blindness.

What are the symptoms?

Symptoms vary and include night blindness (inability to adjust vision in the dark, or a very slow adaptation). In later stages, there is tunnel vision (loss of peripheral vision where the patient can see only through a small central circle).

What are the current treatment options for pigment retinosis?

Unfortunately, there is no effective curative treatment. The best options reduce the rate of progression of the disease and of the visual loss, and they include vitamin therapy. Many patients manage to lead normal lives with training in low vision clinics and require visual aids such as telescopes, loupes, magnification lenses and others in order to improve their quality of life.