Vitreo Retinal
Retina and related services at Ratan Jyoti Netralaya are headed by our eminent specialists Dr. Priyamvada Bhasin, Pioneer in the field of Anterior Segment Microsurgery and Retina & Vitreous Surgery. Dr Moolchand has been working with us as a visiting Consultant- Vitreo Retina Clinic. He did M.B.B.S. from University College of Medical Sciences, Delhi and post graduated from All India Institute of Medical Sciences, New Delhi.
Retina is the inner most layer of the eye. A healthy retina is necessary to transfer the image formed by the eye to the brain. It can be affected by various diseases. The most common of them are:
a) Diabetic Retinopathy
b) Age Related Macular Degeneration
c) Retinal Detachment |
| DIABETIC RETINOPATHY |
4.5% of India’s population is suffering from Diabetes Mellitus and by year 2025 around 57 million people will have this disease. At present diabetic retinopathy is the leading cause of blindness in United States and is becoming an important cause of blindness in the developing countries also. In India, it was the seventeenth cause of blindness twenty years ago. But today diabetes related blindness has rapidly ascended to the sixth position.
Early detection and timely treatment of diabetes can substantially reduce the risk of vision loss or blindness from diabetic eye disease. However most diabetic patients are not aware of the fact that their eyes will be affected due to diabetes and this is especially true for people who have had diabetes for five years or more. |
| Frequently asked questions :- |
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| Are the eyes of all diabetics affected ? |
| Eyes of about 80% of the diabetic patients are affected over time. The longer the duration of diabetes greater are the chances of developing retinopathy. |
| What are all the ways? In which diabetes can affect the eye? |
Eye can be affected in many ways; important among these are:
a)Diabetic Retinopathy
b)Early Cataract formation (i.e. clouding of the lens)
c)Glaucoma (i.e. Increase pressure inside the eye) |
| What is diabetic retinopathy? |
| Diabetic retinopathy is a disorder of retinal blood vessels resulting from diabetes mellitus. In this condition, the retinal blood vessels are affected causing insufficient supply of oxygen and nutrients needed by the retina to remain healthy. There are bleeding spots and deposits of fatty material with swelling of the retina. Thus the retina is unable to transmit visual messages to the brain resulting in low vision or blindness. |
| How does it cause low vision or blindness ? |
| In moderate cases, the visual loss is due to swelling and bleeding within the retina. But in many cases vision is lost due to severe bleeding inside the eye from the abnormal blood vessels in the retina, leading to blindness. In advanced cases it may be because of tractional retinal detachment. |
| What are the symptoms by which diabetic retinopathy can be identified? |
| Usually diabetic retinopathy is symptomless . Some people have slight decrease of vision or foggy vision. Some may have normal vision till they develop sudden blindness due to bleeding. As there are no symptoms in early stages of diabetic retinopathy, it is essential that diabetic patients undergo a routine checkup by an eye specialist every six months. |
| How is diabetic retinopathy diagnosed? |
1. Retinal Examination: Under dilatation by an ophthalmologist will help to detect diabetic retinopathy in early stages.
2. Fundus Fluorescein Angiography: In FFA, we take photographs of the Retina after injecting a dye in the arm. It helps us to diagnose the stage of Diabetic Retinopathy in selected cases and localizing leaking new vessels which can be lasered later. |
| How is diabetic retinopathy treated? |
1. Early diagnosis of Diabetes Mellitus and effective control of blood sugar through diet, exercise and medication can help reduce your risk of developing these eye problems associated with Diabetes Mellitus.
2. Laser photocoagulation is the main treatment of diabetic retinopathy.
a) Laser (Light Amplification by Simulated Emission of Radiation) is low energy and highly concentrated light. Each Laser has a specific wavelength. Wavelength generally used for retinopathy is 532 nm.
b) Laser treatment is an OPD procedure. After putting anesthetic (numbing drops) in the affected eye, the patient is comfortably seated on a stool/chair with chin and forehead stabilized. A contact lens is then inserted in the eye and laser beam is focused onto the retina.
c) The light is absorbed by pigment layer of the retina, where it is converted into heat.
Laser photocoagulation helps to preserve vision by preventing new blood vessel formation. It may also help in reducing the swelling of thickened retina in some cases and prevent further deterioration of vision.
Photocoagulation may not be appropriate for every body. If the condition is too advanced laser treatment is not possible. In such cases, vitrectomy may be required.
d) Laser is not a one time treatment. Doing laser once will take care of present retinal leakages. Diabetes is an ongoing disease and it may affect retina again and so regular follow-ups are mandatory. Multiple laser treatments over time are sometimes necessary.
3. Vitrectomy: Vitreous surgery is a time consuming (generally takes 2-3 hrs) surgical procedure in which the blood and scar tissue is removed from the vitreous cavity and from the surface of retina. Sometimes silicone oil or gas is required to stabilize the retina. Following vitrectomy, vision improves to a variable level in most patients. |
| Age Related Macular Degeneration |
What is ARMD?
Age related Macular Degeneration (ARMD) is a disease that causes progressive degeneration of the macula. Macula is the central part of the retina that allows us to see fine details. Many people develop Macular Degeneration as part of body’s natural ageing process. This condition, which is the commonest cause of blindness in the Western World after the age of 65, is now becoming common in our country too. In the past, treatment for ARMD was limited but extensive research on the subject has made its management possible, thereby helping the elderly retain their vision and improve their quality of life.
With improvements in socio-economic conditions, comes longevity and with longevity incidence of Age Related Macular Degeneration increase.
Forms of ARMD
The two most common types of age related macular degeneration are:
Dry Macular Degeneration (atrophic): This type is the more common form of the disease and accounts for 90% of all ARMD. It is caused by ageing and thinning of the tissues of the macula. Vision loss is usually gradual and may take years. Low vision aids may help the patient to do reading and near vision work.
Wet Macular Degeneration (exudative): This form is characterized by development of abnormal blood vessels beneath the retina. These vessels can bleed and eventually cause scarring, leading to profound loss of central vision. The progression of Wet ARMD is generally fast and causes profound loss of central vision in weeks to months. Hence, Wet ARMD needs to be treated as early as possible.
This form is characterized by choroidal neovascularization (CNV), the development of abnormal blood vessels beneath the retinal pigment epithelium (RPE) layer of the retina. These vessels can bleed and eventually cause macular scarring which can result in profound loss of central vision (disciform scar).
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| Fundus Photography showing Dry AMD |
Fundus Photography showing Wet AMD |
What Are the Symptoms of Macular Degeneration?
Early stages of Macular Degeneration may not cause decrease in vision. Sometimes only one eye loses vision while the other eye continues to see well for many years. The condition may be hardly noticeable in its early stages. But when both eyes are affected reading and close work can become difficult. You may experience one or more of the following symptoms.
- Straight lines look distorted, especially at the centre of vision
- Colors look dim
- Words on a page look blurred
- A dark or empty area appears in the centre of vision
Progression of Macular Degeneration
If there is macular degeneration in one eye, then the fellow eye is at high risk of developing macular degeneration as well. The risk of the fellow eye developing macular degeneration is reported to be 38% - 55%.
Treatments for ARMD :
LASER SURGERY and PDT
Although accounting for 10% of all cases of ARMD, Wet ARMD causes severe vision loss. Recent studies have proven that selected patients have much less chance of significant visual loss if they are treated by Laser photocoagulation (Hot Lasers) than if they are not treated. Only 20% of the patients of Wet ARMD can be treated with Laser photocoagulation.
PDT is a type of cold laser which is used in patients on whom the neo vascular membrane is below the centre point of the eye (fovea i.e. sub foveal). The aim of this treatment is to stabilize the existing vision, but vision improvement occurs in less than 5% of the patients following the treatment.
ANTI – VEGF TREATMENT
The latest development for treating Exudative ARMD are specific drugs which target a specific chemical that is critical for causing abnormal blood vessels to grow under the retina. This chemical is called vascular endothelial growth factor (VEGF). Anti - VEGF drugs block the factors causing VEGF, reducing the growth of abnormal vessels and slowing their leakage.
These drugs can even partially reverse the process of deterioration in up to 30 – 40 % of patients.
Fact about ARMD
However, despite advanced medical treatment, some patients with Macular Degeneration will still experience vision loss because the problem in these therapies is that they need to be repeated at monthly or two monthly intervals depending on response. Further research is on to develop treatments to help such patients.
COMBINATION THERAPY
Lot of patients of ARMD requires combination treatment which includes treatment with laser/PDT and VEGF Inhibitors. Let your ophthalmologist decide what is best for your eye.
LOW VISION AIDS
In advanced stages of ARMD low visual devices like stand or handheld magnifiers help in making the day to day activities easier.
- Dry ARMD causes gradual vision loss.
- Wet ARMD causes severe, painless, irreversible vision loss.
- If detected early, Wet ARMD is treatable.
- Regular eye check ups and early detection can prevent blindness due to ARMD.
- Nutritional supplements with Vitamin C, E, beta carotene and zinc can lower the risk of developing advanced stage ARMD.
- PDT can stabilise vision in majority.
- Anti-VEGF therapy helps salvage and improve vision.
- Repeat Injections may be required to arrest the disease.
Check your Central Vision with the Amsler Grid
The Amsler Grid is used to test the macula, the central part of the retina responsible for vision. It consists of a grid made of evenly spaced horizontal and vertical lines with a small dot in the center for fixation. To perform the test, follow the instructions given below.
- Hold the grid 30 cm from the eye
- Close one eye
- Focus on the dot in the center of the grid
Answer the following questions:
- Can you see the corners and sides of the square?
- Do you see any wavy lines?
- Are there any dark or missing areas?
If the lines of grid do not look straight or areas appear missing or distorted, please get your eyes checked by a retina specialist. |
| RETINAL DETACHMENT |
| When a retinal detachment develops a separation occurs between the neurosensory retina and the pigment epithelium. |
| What are the symptoms of a retinal detachment? |
Retinal detachment is generally preceded by the formation of holes(s) or tears in the retina; symptoms of which may include sudden onset of flashes and floaters-(multiple black spots or cobweb like floating objects in front of the affected eye).
When detachment occurs, further symptoms may include-shadow in front of eye, curtain like thing in front of eye, decreased vision or total obscuration of vision. |
| What causes a retinal detachment? |
Nearly all retinal detachments develop because of a hole or tear in the retina. This usually occurs when the retina becomes 'thin', which can occur in short sighted people (Myopia) or if the vitreous (the jelly-like substance that fills the eye) separates from the retina. Previous eye surgery and any ocular trauma can occasionally be the cause of a retinal detachment.
The other causes for detachment include:
1. Exudative detachment- in choroiditis/tumors/inflammation of eye
2. Tractional detachment-in diabetic patients. |
| Examination & Diagnosis |
You will have a sight test and a full eye examination. Eye drops are put into both your eyes to make the pupils bigger, which helps the ophthalmologist to examine the back of the eye fully. The effect of these drops will wear off after a few hours, but your vision will be blurred temporarily preventing you from reading and driving.
Avoid driving yourself to hospital or to the local railway station whenever you come to have your retinas examined because your pupils will always need to be dilated.
If you are diagnosed with a retinal detachment, you will be advised to have surgery as soon as possible to reattach the retina.
Depending on the causes and condition of your retinal detachment, there are a number of different treatment options: |
| TREATMENT |
A retinal hole or tear
To seal the retina around the tear and prevent the retina peeling off you may be asked to have:
Laser - the retinal hole can be heat sealed (like spot welding) by directing a laser beam of light through the pupil of the eye. The scar produced seals the hole
OR
Cryotherapy - a freezing treatment applied by a pen shaped probe to the outside of the eye. This freezes through to the retinal hole and promotes scar tissues as a seal.
These procedures may be a little uncomfortable but not painful, and are usually performed under a local anaesthetic as an outpatient procedure. However, they are only effective for retinal holes or tears, without any detachment. |
| A detached retina |
In addition to the above treatment a detached retina will need a surgical procedure such as application of an encircling band or sponge to support the detached retina with or without drainage of sub-retinal fluid.
In patients with old detachment where retina is fixed and immobile, complicated vitreous surgery is generally required to put the retina back to its normal position. This is a time consuming surgery and takes 2-3 hrs. Usually silicone oil or gas is injected inside the eye to stabilize the retina. |
