Common Retinal Diseases


Retinal Detachment


The retina is a thin, light-sensitive layer at the back of the eye. The lens of the eye focuses light on the retina like the light focused on the film or sensor in the camera. The retina then converts this light into signals that are carried to the brain.
The retina has 10 microscopic layers.

What is Retinal Detachment (RD)?
It is a disorder in which retina peels away from underlying layers which may lead to vision loss or blindness. It is a medical emergency.
There are 3 types of RD:-
  • Rhegmatogenous RD
  • Tractional RD
  • Exudative RD


Rhegmatogenous Retinal Detachment
It is the most common type of retinal detachment. ‘Rhegma’ means ‘break’, hence in this type of retinal detachment the cause is a hole or break somewhere in the retina. Any break (tear or hole) in the retina allows the fluid (vitreous) within the eye to pass through the tear and get behind the retina. This fluid pushes the retina forwards, causing it to get detached.

  • Tear or hole in retina
  • Fluid enters through it
  • Fluid separates the retina from the layer providing nutrition and oxygen to retina
  • Retina detaches


Risk Factors
  • Posterior Vitreous Detachment (PVD)
    • Common age-related condition , in which the jelly within the eye (vitreous) gets separated from the retina, pulls on it, and tears it.
  • Pre-existing weak spots in the retina – lattice degeneration, retinal holes, etc.
  • Injury
  • Myopia (short-sightedness, needing minus-power glasses)
  • Complicated cataract surgery


What does a patient experience?
Sudden, painless loss of vision of one eye Feeling a ‘shadow’ or ‘curtain’ coming down in front of the eye Problems in the vitreous jelly can produce ‘floaters’ – cobweb or thread-like shadows which move around within the eye ‘Flashes’ or ‘sparks’ of light due to the vitreous jelly pulling on the retina

What is the treatment for retinal detachment?
There is no medical treatment for retinal detachment, like injections, tablets or eye drops. This problem can only be treated with surgery, and the sooner the better.

In its earliest stages, external laser can be done to seal the retinal tears or holes, or prevent a small detachment from extending.

Scleral Buckling surgery is an external surgery in which the doctor sews a silicone band to the outer layers of eyeball, which pushes the eye-wall inward against the hole and closes it. This reduces the fluid flow through it allowing the retina to reattach.

Vitrectomy surgery is an internal surgery which involves removal of vitreous jelly, attaching the retina, doing laser to seal the holes, and replacing the vitreous with silicone oil or gas.

Important Pearls
Detection and treatment of RD is best done by a specialist vitreo-retinal surgeon.

After surgery, the patient have to keep his/her head in a particular position for a few days, if gas or silicone oil has been injected.

Retinal detachment is a medical emergency, as the earlier it is treated, the better is the outcome.


Retinitis Pigmentosa


Retinitis pigmentosa (RP) refers to a group of inherited diseases that affect the light sensing cells (photoreceptor cells) responsible for capturing images from the visual field. These cells line the back of the eye in the layer known as the retina. People with RP experience a gradual decline in their vision because the two types of photoreceptor cells – rod and cone cells – die.

Rod cells are present throughout the retina, except for the very centre, and they help with night vision. Cone cells are also present throughout the retina, but are concentrated in the central region of the retina (the macula).

They are useful for central (reading) vision and for colour vision. In RP, the rod cells, and eventually the cone cells stop working, causing vision loss; however, many people with RP retain useful central vision well into middle age.

What are the symptoms of RP?
There can be a very variable range in the onset of RP. Some people are diagnosed in childhood while others are not affected until they are adults.
  • Earliest difficulty is seeing in dim light (night-blindness)
  • Tunnel vision
  • Bumping into objects
  • Complete loss of vision only in very severe and advanced cases

What is the cause of RP?
RP is a genetic disease, but cases with no family history also commonly occur. There are various inheritance patterns for RP, including:
  • Autosomal dominant (30-40%),
  • Autosomal recessive (50-60%) and
  • X-linked Recessive (5-15%).

The autosomal dominant form of disease tends to follow a milder course with maintenance of preserved vision well into late middle age. The X-linked form is the most severe and central vision may be lost by the third decade.

If a family member is diagnosed with RP, it is strongly advised that other members of the family also have an eye exam by an eye doctor (ophthalmologist)

What treatments are available for RP?
There are, as of yet, no proven or effective cures for RP, although research in this area has recently accelerated.
A wide range of assistive technologies for people with visual impairments provides plenty of choice for users at all stages of sight loss. Maximizing the remaining vision that an individual has is a crucial first step to take.

  1. Spectacles
    RP patients usually have short sightedness (myopia), thus correction by spectacles not only improves vision but also enlarges the visual field.
  2. Low Vision Aids
    There are many new low vision aids including telescopic and magnifying lenses. The full-fledged Low Vision Clinic at Laxmi is one of only a handful in the entire region.
  3. Medications
    Its effectiveness is variable and generally limited. Vitamin A has only modest benefit, and can have significant side effects
  4. Cataract Surgery
    RP patients tend to develop cataracts at an earlier age and can do very well from cataract surgery, although the visual outcome obviously depends on the severity of the retinal degeneration. Laxmi Eye Institute is a world-renowned centre of excellence in cataract surgery.
  5. Glaucoma management
    RP patients can have associated Glaucoma (3%). Treating it can preserve vision to some extent. At Laxmi Eye Institute we have dedicated glaucoma specialists and the most sophisticated diagnostic equipment and treatment strategies.
  6. Macular edema management
    Drug therapy and injections can enhance vision. These are administered by our highly qualified retina specialists at Laxmi Eye Institute.
  7. Gene therapy
    Therapy to replace defective genes is being explored in clinical trials for a small number of RP genes.
  8. Newer Technologies
    For individuals who may have lost a significant portion or all of their vision, there are other technologies that are currently being investigated, such as stem cell therapy and retinal chip implant technologies (e.g. Argus).


Prognosis
The disorder generally continues to progress, although very slowly in most cases. However complete loss of vision is very uncommon. There are many means by which vision can be maximized. Laxmi Eye Institute is a centre where multiple eye specialists and technologies are available for this purpose.



Diabetic Retinopathy


Diabetes affects the blood vessels of the entire body, but damage is mostly seen in the blood vessels of the eye (retina), kidneys, heart, and brain.

Diabetic retinopathy is a condition in which blood vessel damage leads to their blockage, bleeding, leakage of blood proteins and water, and formation of new blood vessels.

Diabetic Retinopathy (DR) is an important cause of permanent vision loss, and can even lead to blindness.

Who is at risk of developing diabetic retinopathy?
Patients who are diabetics with fluctuating blood sugar levels, long-term diabetes, and diabetic who also have high blood pressure (hypertension), high cholesterol, kidney disease (nephropathy), and who smoke, are at a higher risk of developing retinopathy.

Can diabetic retinopathy be prevented?
Yes, it can be prevented by keeping the blood sugar levels under tight control. Adequate control of other parameters like blood pressure, cholesterol levels, nephropathy is also essential to prevent and or delay progression of diabetic retinopathy.

What are the signs and symptoms of Diabetic Retinopathy?
In the early stages diabetic retinopathy may not have any symptoms at all and serious retinal changes may co-exist with normal vision.

In advanced stages, the patient may experience:
  • Sudden drop in vision, due to internal bleeding or retinal detachment
  • Gradual decrease in vision or blurring, due to retinal swelling (edema)
  • ‘Floaters’ or black or red-coloured spots, due to internal bleeding


What are the types of Diabetic Retinopathy?
DR proceeds through various stages. In the early stages of the disease, the patient most often does not have any vision-related complaints. If such a stage is reached, treatment can be initiated to preserve vision for the rest of one's life.

Two main retinal problems are seen in DR
  1. New blood vessel formation (Proliferative Diabetic Retinopathy, PDR) – which can lead to internal bleeding and retinal detachment
  2. Leakage in the central retina (Macular Edema) – which causes retinal swelling and drop in vision

Both these problems need to be tackled simultaneously.

How does one diagnose DR?
The best method is by dilated fundus examination by a qualified retina specialist. Eye drops are used to dilate the pupils of the eyes, which allow the retina to be seen in full detail.

Your retina specialist may advise certain tests:
  1. Fundus Photography: This test serves as a record of the present status, which is useful for comparing any changes that may occur with time.
  2. OCT (Retinal scanning): This test can confirm retinal swelling (macular edema) and also measure the actual retinal thickness
  3. FFA (Angiography): In this test, a dye is injected in the hand veins and photographs of the retina are taken. Specific areas of leakage, abnormal blood vessels, and blockages can be visualized.


Laxmi Eye Institute is proud of its full-fledged diagnostic centre, equipped with the latest and most sophisticated equipment, including the Avanti OCT by Optovue.

What are the treatment options for diabetic retinopathy?
Prevention is better than cure. By keeping one’s diabetes under control, sight-threatening problems can be prevented. Damage that has already occurred cannot be reversed, but further damage can be delayed or averted.

  1. Retinal Laser can be used to close the new blood vessels that develop in PDR. Once these blood vessels close, the risk of future bleeding or retinal detachment is minimized
  2. Eye injections (Accentrix™ or Lucentis™, Avastin™, Ozurdex™, triamcinolone) are helpful in reducing the retinal swelling and improving vision.
  3. Vitrectomy surgery may be required to remove blood within the eye that does not dissolve on its own, or to restore the retina to its normal position.

All these treatments are available at Laxmi Eye Institute and are administered by our highly qualified retina specialists. This is one of the only centres in the region equipped with the latest Multi-spot Retinal Laser by Carl Zeiss, Germany.

Protect Your Eyes
You can protect your eyes from losing vision due to diabetic retinopathy. Meet your retina specialist every year for a retina check-up. Early diagnosis and treatment can preserve vision for the rest of your life.


Age-related Macular Degeneration


As the name suggests, this is a disease that occurs due to ageing. It is seen in people above the age of 50 years. In this disease, it is the ‘macula’, the central area of the retina, that gets damaged.

AMD is one of the leading causes of irreversible low vision in the world. It is very common in the western world, principally because of a longer life-span, but is now being recognized more and more in India.

Who is at risk of developing AMD?
This disease can occur in anybody after the age of 50 years. Studies have shown a few other risk factors:
  • Hypertension
  • Smoking
  • Family history
  • Specific genetic mutations


What are the signs and symptoms of AMD?
The earliest and sometimes only symptom in painless loss in vision. The patient may experience difficulty in reading, or looking at far-off objects clearly, or recognizing people’s faces. Sometimes this may be noticed suddenly by the patient when they close one eye, as the disease can occasionally affect one eye more than the other.

Another important symptom is ‘waviness’ of objects that should be straight. This distortion is called metamorphopsia.

AMD affects only the central vision. Patients may notice a central black spot wherever they try to focus, but it never causes total blindness.

What are the types of AMD?
In general there are two types of AMD – Dry and Wet.

Dry AMD is significantly more common than the wet form. However it can slowly progress to the wet stage. This stage is characterized by slowly progressive damage to the photoreceptor and retinal pigment epithelial cells.

Wet AMD is less common, but 90 percent of patients with vision loss due to AMD have this type of disease. In this stage, new blood vessels begin to develop underneath the retina (‘neovascularization’), which lead to bleeding and leakage of water into and below the retina.

How does one diagnose AMD?
The best method is by dilated fundus examination by a qualified retina specialist. Eye drops are used to dilate the pupils of the eyes, which allow the retina to be seen in full detail.

Your retina specialist may then advise certain tests:
  1. Fundus Photography: This test serves as a record of the present status, which is useful for comparing any changes that may occur with time.
  2. Fundus Autofluorescence: A special type of photograph, it can clearly delineate the extent of damage in patients with dry AMD.
  3. OCT (Retinal scanning): This test can detect retinal swelling (macular edema) and also measure the actual retinal thickness for future reference.
  4. FFA (Angiography): In this test, a dye is injected in the hand veins and photographs of the retina are taken. Specific areas of leakage, abnormal blood vessels, and blockages can be visualized.


Laxmi Eye Institute is proud of its full-fledged diagnostic centre, equipped with the latest and most sophisticated equipment, including the Avanti OCT by Optovue.

What are the treatment options for AMD?
This disease cannot be entirely cured or reversed.

In the dry stage, treatment is aimed at stabilizing or slowing the speed at which worsening occurs. This is the rationale behind prescribing antioxidant and vitamin supplements.

In the wet stage, treatment tries to halt further damage, and in early cases vision can improve significantly. The medication required is administered directly into the eye in the form of injections. A number of drugs are available – namely Avastin™, Accentrix™ (formerly called Lucentis™), and Eylea™. All of these are regularly administered at Laxmi Eye Institute.

Occasionally, a highly specialized type of ‘cold’ laser called PDT (photodynamic therapy) is useful. In this procedure, a dye Verteporfin™ is injected in the arm, and laser light is applied to the abnormal retina blood vessels.

Remember, early treatment can help to stabilize vision and can even improve vision.