EYE AILMENTS GUIDE

Causes:

• Aging: Cataract formation is a natural part of the aging process (just like graying of hair or wrinkling of skin).
• Severe Eye Injury: Either injury by mechanical, thermal, chemical, electrical or by radiation.
• Congenital: This may be inherited or may be present at birth, due to infections, like German measles, in the mother during pregnancy.
• Other Systematic Diseases: Like eye inflammation, tumors or general body disorders like diabetes.
• Excessive or Indiscriminate: Use of certain drugs like corticosteroids. Most people regain the vision they had earlier with microsurgery (Cataract Extraction).

Symptoms:

• Painless, gradual, progressive blurring of vision.
• Discomfort or inability to see in bright light.
• Double or multiple images.
• Colours appear dull.
• Change in colour of pupil of the eye to grey or white.

Diagnosis and Treatment

• Cataract cannot be prevented, delayed or stopped with medication.
• Surgery is the only cure, wherein the opaque lens is removed and replaced by intra-ocular lens implant.
• Modern Cataract surgery is done under eye drops (topical anaesthesia). It is performed as a day care surgery and admission is not required. Post-operative recovery is extremely rapid and most of the activities can be resumed within a day.

AMD (AGE RELATED MACULAR DEGENERATION)

What is AMD ?

AMD – age related macular degeneration is a retinal condition which as name indicates is seen increasingly with increasing age. It affects the central retina (The Macula) and causes distortion and loss of vision.

What happens if someone has AMD?

In early stages patients develop bending of lines, mild loss of vision. In late stages they will develop loss of central vision. They may see a dark spot in the field of vision with surrounding clear area. This central area may enlarge with worsening disease.

• Distorted vision (i.e. metamorphosis) – A grid of straight lines appears wavy and parts of the grid may appear blank.
  

  NORMAL

  ABNORMAL
• Trouble in differentiating colours and their intensities.
  

  NORMAL

  ABNORMAL
• Slow recovery of visual function after exposure to bright light.
• Difficulty in reading, watching television, and recognizing faces.

What are the causes for AMD?

• Increasing age
• Genetic predisposition
• Smoking
• Environmental factors

Types of AMD

There are 2 types of AMD – ‘Dry’ and ‘Wet’

• Dry AMD: Here the visual loss tends to be very gradual, over 5-10 years or so. This is the most common form and occurs in 9 out of 10 cases.
• Wet AMD: Occurs when abnormal blood vessels behind the retina start to grow under the macula. These new blood vessels tend to be very fragile and often leak blood and fluid. This occurs in about 1 in 10 cases.

How can AMD be detected?

• Visual acuity
• Dilated fundus examination
• Fundus photography
• Special investigations such as Optical coherence tomography, Fluorescein angiography and Indocyanin green angiography

What treatment options are available for treatment of AMD?

Anti oxidant supplements – large studies have found that supplementing certain dietary components can reduce the progression of dry AMD and reduce the risk of severe visual loss in wet AMD. Your doctor will be able to prescribe the correct antioxidants for you.

1. Anti VEGF injections – Anti VEGF such as Ranibizumab and Bevacizumab can be given as an injection into the vitreous cavity (gel inside the eye) which will help in regression of the New vessels in the wet AMD. These injections need to be repeated every 4-6 weeks.
2. Photodynamic therapy – An sensitizing injection is given to the forearm of the patient and eye is treated with special type of laser. This treatment is used currently in resistant form of AMD.

How can we prevent AMD?

Eating a good portion of fresh fruits and vegetables to provide us necessary antioxidants.
Regular retina check up especially if you have a family history of AMD.
Self examination with Amsler’s grid (your doctor will provide you with one)
These measures can help in delaying the progression of AMD and early detection. Early detection is the key to maintaining good vision in AMD.

REFRACTIVE ERRORS : MYOPIA

Myopia causes distant objects to appear blurred, while close objects can still be seen clearly. Myopia usually appears around puberty, but may appear at any age from early childhood up to the age of 25. In most cases, myopia will stop getting worse when the growth process has been completed.

Causes:
There is a tendency for myopia to run in families.
Children have about 30% chance of developing myopia if one of their parents has myopia and 55% chance if both have it. High degree myopia (pathological myopia) also runs in families.

Symptoms:

• Seeing distant objects such as the blackboard at school may become difficult, while near objects can still be seen clearly and they may think this is ‘normal’ and not tell anyone.
• Schoolwork may suffer for a while before the condition is identified and treatment is provided.
• Other symptoms can include headache and tired eyes.

Myopia that starts in early childhood often gets worse in adult life and may become very severe. It is known as high degree myopia (or sometimes as pathological myopia). It can create problems in later because of its association with changes at the back of the eye.

Complications:
High degree myopes (pathological myopes) are more likely to develop eye disorders in later life, which includes –

• Degenerative changes in the peripheral retina including thinning that can easily develop into tears, holes and retinal detachments.
• Retinal detachment
• Glaucoma
• Cataracts

Signs of Retinal Detachment:
Every patient with myopia must know the signs of retinal detachment.

• Sudden appearance of flashes of lights, like lightening flashes, floaters, little shadowy dots, cobwebs or strands could be the first sign of an impending retinal detachment or a tear of the retina.
• If a person experiences the sudden onset of both flashes and floaters at the same time, the risk of detachment is extremely high.

In retinal detachment, the person may notice impairment in one area of his vision described like a curtain coming down. This can occur from any direction including the right or left side or from the top or bottom of the vision.

Management for short sightedness:

• Spectacles: These are the common treatment. They have a concave lens which bends the light rays slightly outwards. Therefore the light rays have a greater angle to bend back to focus when going through the cornea and lens. This means they focus further back – on the retina.
• Contact Lenses: These are an option and do the same job as glasses.
• Simple Procedure: Various types of operations have been developed to ‘cure’ short sight. The most popular at present is Laser correction of refractive errors in which computer guided laser ablation of Cornea is done. In higher power Phakic ICL is another modality of treatment.

Regular Retinal Monitoring:
The best way to reduce the risk of vision loss is to have regular dilated retinal examinations, rather than a casual change of glasses at an optical shop and to seek immediate eye care if one has any flashes, floaters or decrease in one’s vision.

REFRACTIVE ERRORS: UVEITIS

Uveitis is an inflammatory disease of one or both eyes that occurs in the middle layer of the eye.
It can also lead to inflammation in the adjacent areas, like the retina and fluid in the back of the eye (called vitreous). Uveitis will in severe cases lead to permanent loss of vision/blindness on the affected eye.

Causes:
Uveitis can be caused by autoimmune disease, infections and rarely trauma, but 50 % of the cases remain of unknown origin.
Intraocular infections are from previous studies, known to be responsible for approximately 40 % of the cases of severe forms of uveitis. Most infectious causes of uveitis have the potential to be treated with antibiotic. Most infectious causes of uveitis are under normal condition only possible to detect by using very specific detection methods. Further more it is often necessary to study a sample from with-in the eye (vitrectomy to get a proper diagnosis.

It can result from allergy, bacteria, viruses, fungi, chemicals, trauma, or surgery; or it may be associated with systemic diseases, such as rheumatoid arthritis, ankylosing spondylitis, and toxoplasmosis. Uveitis occurs in 15 of every 100,000 people.
Symptoms:

• Hazy vision
• Vision disturbance
• Deep eye pain
• Photophobia
• Eye redness
• Eye pain
• Light sensitivity
• Blurred vision
• Dark, floating spots in your field of vision (floaters)
• Decreased vision
• Sudden appearance and rapid worsening of symptoms
• Effects noticeable in one or both eyes
• Variable site of inflammation – sometimes only the front of your eye (anterior uveitis, iritis) or the back of your eye (posterior uveitis), and sometimes all three layers of the uvea (panuveitis)

Diagnosis
Confirming diagnosis, a slit-lamp examination shows a “flare and cell” pattern, which looks like particles dancing in a sunbeam. With a special lens, slit-lamp and ophthalmoscopic examination can also identify active inflammatory fundus lesions involving the retina and choroid, although a hazy vitreous may obscure the view.

DIABETIC RETINOPATHY

What is diabetic retinopathy ?

It is a disease that occurs in the eye as a result of long standing and uncontrolled diabetes.

What happens if one has diabetic retinopathy?

Early stages will not cause any symptoms to the patient. But in later stages patient can develop blurring of vision due to swelling of the center of the eye ( Macula) , severe loss of vision due to bleeding inside the eye (vitreous hemorrhage) , retinal detachment due to pull on the retina by the new vessels (Tractional retinal detachment).

How do I know if I have a diabetic retinopathy?

Dilated examination of the retina by a retina specialist can detect diabetic retinopathy at the earliest stage.

My diabetes is under very good control , can I still have diabetic retinopathy?

Yes. There are other contributing factors for development of diabetic retinopathy such as duration of diabetes, assosiated hypertension , lipid levels in the blood , genetic predisposition. Hence there is chance that one can develop diabetic retinopathy dispite having good control of diabetes. How ever good control of diabetes can significantly reduce the chances of progression of diabetic retinopathy to severe forms.

What are the types of diabetic retinopathy?

There are two main types of diabetic retinopathy:
1. Non – proliferative( not assosiated with growth of blood vessels) and
2. Proliferative (assosiated with growth of new blood vessels)

Either of these can be associated with swelling of the center of retina – macular edema.

What treatment options are available for complications of diabetic retinopathy?

1. Lasers – This is the main stay of treatment proliferative diabetic retinopathy( where new blood vessels have grown in the eye). Eye will be anesthetized and laser spots are given through a lens that is placed on the eye. 3-5 sittings of laser may be required depending on the severity of condition. Some times one may require more laser if the response to initial treatment is not adequate.
2. Intravitreal injections – drugs such as Ranibizumab , Bevacizumab are given inside the eye for treatment of macular edema ( swelling in the eye) or before a surgery to reduce bleeding.
3. Surgery – surgical intervention may be required to remove the blood accumulated in the eye or to relieve the tractional retinal detachment.

GLAUCOMA

What is Glaucoma?

It is a progressive disease of the optic nerve due to the high pressure in the eye called intraocular pressure (IOP). It can also occur at normal intraocular pressures. The optic nerve carries
information regarding vision from the eye to the brain.

Initially the patient loses the peripheral field of vision and if left untreated it can result in blindness.

It is the second most common cause of preventable blindness after cataract.

What are the risk factors for Glaucoma?

• Those with raised intraocular pressure
• People with a family history of glaucoma
• Extremes of refractive errors like myopia and hypermetropia
• Patients having a previous history of eye trauma
• Those who have been using steroids for prolonged periods in the form of eye drops ,nasal sprays, inhalers ,ointments and tablets
• Diabetes Mellitus
• High Blood Pressure or Low Blood Pressure

Early detection through regular and complete eye examinations is the key to protecting your vision from damage caused by glaucoma.

What are the types of Glaucoma?

It is of two main types: OPEN ANGLE GLAUCOMA and CLOSED ANGLE GLAUCOMA.
This usually affects adults.
Glaucoma also can affect children. It is called CONGENITAL GLAUCOMA.

What are the symptoms of Glaucoma?

Glaucoma is called the “silent thief of sight”. It rarely causes any symptoms until an advanced stage. When the peripheral field of vision is lost to such an extent that he is left only with a “tunnel vision”.
In the closed angle glaucoma the symptoms are due to the sudden increase in the pressure in the eye.
The symptoms include :

• Severe eye pain
• Redness
• Blurred vision
• Headache
• Nausea and vomiting
• Seeing colored haloes

What should I do next?

Early detection through regular and complete eye examinations is the key to protecting your vision from damage caused by glaucoma.

Detecting Glaucoma

It involves a complete and systematic examination of the eye.

• Thorough slit lamp evaluation of the front part of the eye
• Tometry: IOP measurement
• Gonioscopy : To evaluate the drainage angle of the eye
• Optic nerve head examination
• Computerised Perimetry (Visual Field Analyzer): To assess the field of vision
• RNFL Analyzer: To detect the thickness of the retinal nerve fiber layer

Is there a cure?

With early diagnosis and proper medications the disease can be controlled. The damage which has occurred is irreversible.
Once disease is confirmed it requires a long term and ongoing treatment, hence the need for regular follow ups.

What are the treatment options for Glaucoma?

The aim of all modalities is reduction in eye pressure.
The main options include :

• Medical management
• Laser treatment
• Surgical treatment

The treatment options are tailor made according to the stage and severity of the disease. With proper and timely management vision damage can be minimized and the rate of the disease progression can be slowed down.
Few lifestyle modifications and strict adherence to the treatment protocol can go a long way in reducing the morbidity and maintaining the quality of life for a longer period.