Tuesday, May 10, 2016

Glaucoma

Glaucoma






Glaucoma is one of the major causes of blindness that occurs due to optic nerve damage. High level of pressure inside the eye can damage the nerve of your eyes permanently leading to loss of vision. Vision loss will be slow and gradual that many times people may fail to notice it until it reaches advance stage. The only way to prevent this damage is to get your eyes checked regularly if you are above 45 or if you are diabetic. For many people, glaucoma will not show any symptoms except gradual loss of vision. Glaucoma is hereditary and if left untreated it can cause permanent loss of vision.


Symptoms :










There are two main categories of glaucoma namely open angle or primary glaucoma and angle closure glaucoma. Both the types would show symptoms like gradual loss of vision and tunnel vision. Some people may feel eye pain, visual disturbance, blurred vision and formation of halos around light. Advanced stage of diabetes or cataract can also cause glaucoma. Sudden eye injury can cause inflammation of eyes leading to intraocular pressure. If you are diabetic or if you have family history of glaucoma, go for regular eye checkups.


Causes :


Intraocular pressure build-up inside the eyes is the major cause for glaucoma. Under normal condition, eyes are surrounded by special fluid known as aqueous humor. This fluid flows from your eyes through filter like channels. But when these channels are blocked excess of fluid gets build up inside the eyes causing intraocular pressure. What exactly causes this block is not known.


Sometime, the blood vessels of your eye may get blocked causing optical nerve damage. Normally glaucoma develops in both the eyes but extent of damage may differ. In some people, iris would bulge forward which in turn would block the drainage of fluids formed in that area. This causes angle closure glaucoma building up intraocular pressure. For some cases, optic nerve gets damaged without any known cause causing normal tension glaucoma. In rare cases, infants are born with glaucoma and they develop optical nerve damage within few years of birth.


Types :


Open angle glaucoma is the type in which the fluid discharge will not be done properly but the eye structure remains normal. Angle closure glaucoma or chronic angle type is less common. Here the angle or space between the iris and cornea becomes too narrow, blocking the flow of fluids. This builds up internal pressure damaging the optic nerve.


Who are at risk?


People with high level of intraocular pressure are at high risk of developing glaucoma. Elderly people are at risk of getting angle closure glaucoma. People belonging to certain ethnic group like African Americans, Asians and Japanese are likely to develop glaucoma. People with family background of glaucoma have more risk of getting glaucoma than others, since it is believed to run in families.


People living with diabetes for prolonged period, and high Blood Pressure or Hypothyroidism for long are at risk. Intake of certain medications like corticosteroid for long also increases the risk of getting glaucoma. Glaucoma would often slowly reduce your vision causing blind spots and tunnel vision and in final stages total loss of vision.


Tests :


Your eye-doctor would conduct series of test after listening to your symptoms. She would test the extent of optic nerve damage and further conduct visual acuity and visual field test. She would also measure the intraocular pressure in your eyes. She may also use pachymetry test and gonioscopy to get complete picture of glaucoma.


Treatment :


The aim of treating glaucoma is to reduce the intraocular pressure and to restore normal vision. Glaucoma can be cured only if diagnosed in initial stages and the damage caused to the optic nerve is irreversible in the final stages. If the person has already developed vision loss before coming to doctor, she can only help in preventing further loss of vision and cannot restore original vision.


Medicated drops are prescribed to prevent further damage of optic nerve. You need to follow the instructions of your ophthalmologist while using eye drops. Make sure that you are closing your eyes fully for few minutes after applying the eye-drops in it. Drops like latanoprost, bimatoprost are often prescribed for glaucoma. It can cause reddening of eyes and darkened iris.


Beta blockers like timolol or betaxolol are highly effective in reducing the intraocular pressure in your eyes. Alpha adrenergic agonists like lopidine or brimonidine are useful in preventing accumulation of excess of fluid in your eyes. Some doctors use carbonic anhydrase inhibitors and cholinergic agents also. For some people, apart from eye-drops, oral pills are also prescribed.



  • Surgery :


Surgery is done for people whom medications are not effective. Laser surgery like trabeculoplasty is done for treating open angle glaucoma. High energy beam of light is used for opening up the blocked drainage canals so that excess of fluid is drained completely. After the surgery, eye pressure will be checked regularly to prevent any damage. For some people, intraocular pressure will reduce initially following surgery which will continue to rise over time.


Trabeculectomy is another technique in which the eye muscles are relaxed using numbing injection and a small incision is made on the sclera of the eye to remove some part of tissue inside. This would help in draining off the fluid inside the blocked channels. The above two types of surgery will be performed on one eye and after few weeks the other eye will be operated. Drainage implant surgery is done for children affected with glaucoma in which the surgeon will insert tiny tubing into the eye to drain off aqueous humor (fluid) inside.


Prevention Tips :


Glaucoma cannot be fully prevented, but you can always go for regular eye checkups so that you can detect glaucoma in the initial stages. Vision loss caused by glaucoma cannot be reversed and the damage is permanent.











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