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GLAUCOMA Surgery |
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| What is Glaucoma?
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Glaucoma is a diseases of the optic nerve--the part of the eye that carries the images we see to the brain.The optic nerve is made up of many nerve fibres,like an electric cable containing numerous wires.When damage occurs to theoptic nerve fibres,blind spots develop.These blind spots usually go undetected uuntil the optic nerve is significantly damaged.If the entire nerve is destroyed,blindness results.
Early detection and treatment by opthalmologist are the keys to preventing optic nerve damage and blindness from glaucoma.
Glaucoma is a leading casuse of blindness in India,especially for older people.But loss of sight from glaucoma can often be prevented with early treatment.
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What causes Glaucoma?
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Clear liquid callled aqueous humor circulates inside the front portion of the eye.To maintain a healthy level of pressure within the eye,a small amount of this fluid is produced constantly while an equal amount flows out of the eye through a microscopic drainage system.
Because the eye is a closed stucture,if the drainage area for the aqueous humor--called the drainage angle--is blocked,the excess fluid cannot flow out of the eye.Fluid pressure within the eye increases,pushingagainst the optic nerve ad causing damage.
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What are the differant types of Glaucoma?
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| Chronic open angle GlaucomaCOAG : This is the most common form of glaucoma.The risk of developing COAG increases with age.The drainage angle of the eye becomes less efficient over time, and pressure within the eye gradually increases,which can damage the optic nerve.In some patients, the optic nerve becomes sernsitive even to normal eye pressure and is at risk for damage.Traetment is necessary to prevent further vision loss. Typically,COAG has no symptoms in its early stages,and vision remains normal.As the optic nerve becomes more damaged,blind spots begin to appear in the visual field and increase in size as damage progreses.If all nerve fibrews are damaged, blindness results.
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Closed angle Glaucoma : Some eyesare formed with the iris[brown part of the eye]too close to the drainage angle.In these eyes,which areoften small and farsighted,the iris can block the drainage angle completely.Since the fluid inside the eye cannot exit the eye,pressure within the eye rises rapidly and causes acute angle closure glaucoma.
Symptoms may include:
- Blurred vision
- Severe eye pain
- Headache
- Rainbow coloured haloes around lights
- Nausea and vomiting.
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| This is true eye emergency if left untreated can lead to blindness.Unfortunately, many with closed angle glaucoma develop it slowly without any symptoms prior to an attack.
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| Who are at risk for Glaucoma?
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The most important risk factors are:
- Age more than 40
- Elevated eye pressure
- Family history of glaucoma
- Past eye injuries
- Thinner central corneal thickness
- Systemic problems like diabetes,migrain headaches
If you fall in these factors then it means that you are at risk of developing glaucoma.You need to have regular examinations to detect the early signs of damage to the optic nerve.
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| How is Glaucoma detected?
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Regular eye examinations by an opthalmologists are the best way to detect glaucoma.A glaucoma screening that checks only the pressure of the eye is not sufficient to determine glaucoma.
During evaluation,opthalmologist will:
- Meausre your intraocular pressure [TONOMETRY]
- Inspect the drainage angle [GONIOSCOPY]
- Evaluate for any optic nerve damage [OPTHALMOSCOPY]
- Test the peripheral vision of eye [PERIMETRY]
Photography of the optic nerve or computarised imaging[OCT] may be recommened for permanent records.
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| How is Glaucoma treated?
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| As a rule ,damage caused by glaucoma cannot be reversed.Eyedrops,laser treatment and surgery can prevent further damage.In some cases oral medicines may also be prescribed.
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| Medications
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Glaucoma is usually controlled by eyedrops taken daily.These medicines lower the eye pressure by decreasing the amount of fluid being produced in the eye or by increasingthe flow through the drainage angle.
Patients should never stop or change medicines unless adviced.Glaucoma medicines can give rise to some side effects like:red eye ,stinging ,itching,blurred vision,dry mouth,headaches,change in eye colour,changes in pulse rate and haert beats.
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| Laser treatment
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In open angle glaucoma lasers are used to modify the drainage angle--trabeculoplasty
In closed angle glaucoma lasers are used to create a hole in the iris--iridotomy.
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| Surgery
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| Creates a new drainage channel for the fluid to flow out of the eye--trabeculectomy with or without mitomycin, viscocanulostomy.
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