Open angle glaucoma, green cataract

Open-angle glaucoma is an eye disease that causes the optic nerve in the eye to disappear. Increased pressure inside the eye causes retinal damage. The injuries provide a slowly shrinking field of view and without treatment you can become blind. If you have open-angle glaucoma, you will receive treatment and be allowed to go out on life controls.

This text is about open-angle glaucoma. There is another type of glaucoma called acute glaucoma or narrow-angle glaucoma. Read more about acute glaucoma here.

Sometimes open-angle glaucoma is called a “green cataract,” but  cataracts are a completely different disease where the lens of the eye becomes cloudy.

Symptoms of open angle glaucoma

In the case of open-angle glaucoma, the field of vision is slowly shrinking. There are also areas in the field of view where you see nothing. But as it goes slowly, the eye can compensate for the loss of vision. Therefore, most people do not notice the disease until it has been going on for a long time. Then it has often caused damage, for example that the field of view becomes smaller and darker. It does not appear on the outside of the eye that you have open-angle glaucoma even though the spoons may be large.

It is common to first get the disease in one eye and after a while in the other eye.

Often, open-angle glaucoma is detected by chance, for example when you renew glasses at an optician or seek care for something else.

When should I seek care?

If you are concerned or suspect that you have open-angle glaucoma, contact a health care center or eye clinic. You can also contact an optician.

You who have a parent or sibling who has open-angle glaucoma should check your eye pressure regularly after you turn fifty years old. In this way, the disease can be detected early. 

Investigation

In order for the doctor to diagnose open-angle glaucoma , your eye is examined in several ways. Here are some common investigations:

  • Pressure measurement.
  • Examination of field of view.
  • Examination of the optic nerve.

Pressure measurement of the eye

The eye pressure is usually measured with a pressure gauge which is connected to an eye microscope. Then you first get eye drops with stunning and yellow color. The eye drops fade for a few seconds, but do not irritate your eyes and do not blink during the examination. Then the doctor places a plastic cone against the cornea of ​​the eye to measure the pressure. The measurement only takes a few seconds.

The eye pressure can also be measured in several other ways. For example, with an air puff, a special pen that goes against the eye, or a stick that bounces lightly on the eye. The measurement itself goes in a similar way regardless of which pressure measurement method is used.

The survey goes fast regardless of which method is used. Your vision is not affected by the survey.  

Examination of field of view

The field of view is examined by looking at a large, capped screen. Every now and then, lights on the screen will come on which you can confirm if you have seen by pressing a button. The survey usually takes between five and ten minutes.

You do not have to worry because you do not see lit lights all the time. This is normal for everyone in this type of study.

Your vision is not affected by the survey.

You often have to do a field of vision examination at an eye reception. But it can also be done with some opticians.

Examination of the optic nerve

The optic nerve can be examined in several ways. The ophthalmologist examines the optic nerve using an eye microscope. Often, the optic nerve is also imaged by eye photography or an apparatus called OCT. The examinations can also be done by a doctor, a nurse, a nurse or an optician.

Eye Microscope

The eye microscope consists of a magnifier and a lamp. The eye microscope stands on a height-adjustable table. You can sit on one side of the table, with your chin and forehead against a support. You look into the microscope with your eyes completely still, or follow the examiner’s instructions, for the duration of the examination. On the other side of the microscope, the doctor sits and examines the eye by shining a lamp against the eye.

Eyebrow photography and OCT

The optic nerve can also be imaged in several other ways. Sometimes a special camera is used to examine the eyebrow and optic nerve. It’s called an eye-level camera. You then sit in a similar way as when examining a microscope with your chin and forehead against a support when the eye is photographed.

The doctor can also measure the thickness of the nerve fibers coming from the optic nerve with a special device called OCT. It is used to detect the disease and follow the course of the disease over time. Then you have to sit in the same way as with eye-level photography and watch an object for a little while while the device gathers information. It is important that you do not touch the eye when examining OCT.

This is what you can do after examination with an eye microscope, an eyepiece camera and OCT

Prior to an eye microscope, eye camera or OCT examination, you will often receive eye drops that dilate the pupil. The eye drops make it easier for the doctor to see the back of the eye. After the investigation, you may have difficulty reading for a few hours and you should avoid activities where good vision is important for safety. You should not drive a few hours after receiving pupillary drops.

To think about before the visits to the ophthalmologist

It may be helpful to think through what questions you have, before a visit to the ophthalmologist. If you use eye drops, it is good if you bring them with you. Then you can avoid misunderstandings regarding drugs and dosage.

Here are some examples of questions you can ask:

  • How far is the disease progressing?
  • Will vision get worse or has the worsening of the disease stopped?
  • Which type of drug or treatment is most appropriate?

In order for you to be able to  participate in your care and make decisions  , it is important that you understand the information you receive from the healthcare staff. Ask questions if you don’t understand. You can also ask to have the information printed so that you can read it peacefully.

Treatment of open angle glaucoma

The treatment of open angle glaucoma you receive usually prevents your eyesight from getting worse. But it cannot restore vision if it has already been damaged by the disease.

It is most common to get treatment with eye drops but if they do not help you can get treatment with laser. Sometimes an operation is needed.  

The only treatment for open-angle glaucoma is to lower the pressure in the eye. This also applies when the pressure is normal from the beginning. Depending on what the doctor thinks is best for you, you can lower the pressure with either eye drops, laser treatment or surgery.

Eye drops

Eye drops  work by lowering the pressure in the eye . The eye drops can reduce the production of ventricular fluid, increase the drainage of it or both. Chamber fluid is a fluid that forms in the eye and regulates the pressure of the eye.

You can use multiple eye drops

The eye drops can be combined in different ways, for example you can be treated with two different types of eye drops. If you are going to drop several types of eye drops in the same eye, it should usually be at least five minutes in between. This is because the eye holds only one drop at a time and therefore needs some time to be able to take advantage of the drug.  

Eye drops can cause side effects

Eye drops can cause side effects just like other medicines. They may also react with other medicines that you take. Contact your doctor if you get any side effects from the eye drops, then the treatment of open angle glaucoma may need to be changed.

The eye drops can contain different active substances and can be divided into different groups according to how they work.

prostaglandin analogues

Prostaglandin analogues are the most common group of drugs. They increase the flow of chamber fluid and provide the strongest pressure reduction.

Some examples of medicines within the group:

  • Monoprost and Xalatan, which contains the active substance latanoprost.
  • Travatan, which contains the active substance travoprost.
  • Lumigan, which contains the active substance bimatoprost.
  • Taflotan, which contains the active substance tafloprost.

beta blockers

Beta blockers are called a group of eye drops that reduce the formation of ventricular fluid. Some examples of medicines containing timolol are, for example, Timosan and Optimol.

Carbonic anhydrase inhibitors

Carbohydrate inhibitors reduce the flow of chamber fluid to the eye by inhibiting the formation of a particular enzyme.

Some examples of medicines within the group:

  • Azopt, which contains the active substance brinzolamide.
  • Trusopt, which contains the active substance dorzolamide.

Sometimes carbohydrate inhibitors are used as a supplement to beta blockers.

sympathomimetics

Sympathomimetics especially reduce the formation of ventricular fluid in the eye and make it easier for it to drain away.

Some examples of medicines within the group:

  • Alphagan, Glaudin and Brimoratio, which contains the active substance brimonidine.
  • Iopidine, which contains the active substance apraclonidine.

parasympathomimetics

Parasympathomimetics make it easier for the vascular fluid in the eye to drain away. An example is the drug Pilokarpine.

combination Treatments

Sometimes so-called combination treatments are used. Then there are several active substances in the eye drops.

Some examples of medicines containing several active substances:

  • Cosopt and Duocopt containing dorzolamide and timolol.
  • Fotil, which contains timolol and pilocarpine.
  • Xalcom, which contains timolol and latanoprost.
  • Duotrav, which contains timolol and travoprost.
  • Ganfort, which contains timolol and bimatoprost.
  • Taptiqom containing timolol and tafloprost.
  • Combigan containing timolol and brimonidine.
  • Simbrinza containing brinzolamide and brimonidine.

It is important that you take the eye drops as prescribed

Even if you receive treatment, the disease can worsen and become serious. It is important that you remember to take the eye drops and that you take them as prescribed. Every time you forget to take them, the eye pressure rises and then the optic nerve can be damaged.

Laser treatment

Eye pressure can also be reduced with a laser treatment. This is usually done if treatment with eye drops has not helped enough. You can also get laser treatment instead of eye drops.

Then the laser treatment goes on

You may sit under a microscope during treatment. You get anesthetic drops that can burn for a few seconds in the eye to be treated. Then the doctor puts a contact lens on the eye to perform the laser. The treatment takes a few minutes.

Then you do afterwards

The treatment usually does not hurt. You can go home or work afterwards. However, you should not drive a car immediately afterwards as you can see foggy the next hour after treatment.

Operation

You may sometimes need surgery if treatment with eye drops and laser has not helped. There are several different types of glaucoma surgery. They all make the chamber water easier to drain away from the eye and thereby lower the pressure.

The operations take a variety of time but usually take no longer than one hour. You can go home afterwards. You may take eye drops with cortisone for a few months afterwards to suppress inflammation.

You get to go on post checks for the rest of your life

Eye pressure can change over time. You who have open-angle glaucoma may go for regular check-ups at an eye reception. How often depends on how the disease progresses, but most people go under control once or twice a year.

At the check-in, the doctor or nurse can examine the pressure in the eye, your field of vision and your eyebrow. In conjunction with the checks, they can also do a survey of your visual acuity to see if your vision has changed. You can go on the controls for the rest of your life.

What happens in the body?

The eye largely consists of a jelly-like liquid called a glass body. The wall of the eye consists of three layers:

  • The retina and the cornea.
  • Varicose veins, radiators and iris.
  • The retina.

The eye is also divided into three rooms or chambers:

  • The front chamber.
  • Rear chamber.
  • Vitreous.

In the middle of the rainbow is a hole, called a pupil. The pupil regulates how much light is to be let into the inside of the eye. Together with the cornea and the lens, the pupil creates a picture of what you see on the retina. The image is passed on through the optic nerve to the brain.

In order for the eye to retain its shape and function, the eye has a certain pressure. The pressure is regulated by a fluid that forms in the eye called chamber water. The chamber water transports nourishment to the lens and cornea and removes slag products. The fluid is formed in the posterior chamber and flows around the lens and out into the anterior chamber through the pupil. From the anterior chamber, the chamber water flows out through the chamber angle to the blood. 

The optic nerve slowly disappears in open-angle glaucoma

In case of open-angle glaucoma, the optic nerve disappears, causing damage to the optic nerve papilla. This leads to a gradual loss of vision. Open-angle glaucoma causes the field of vision to slowly shrink and areas in the field of vision are formed where you see nothing. The eye compensates for loss of vision because the course of the disease is so slow. Therefore, many people do not notice the disease until it has gone a long way and the vision is greatly affected.

Excessive eye pressure can be a cause

The cause of the disease is not entirely known. One reason may be that circulation in the vessels of the optic nerve has become worse, which leads to the optic nerve disappearing.

Another reason may be that the pressure in the eye is too high in relation to what the optic nerve can withstand.

A high pressure in the eye can increase the risk of getting damage to the optic nerve and visual field, but you can also have a high pressure without causing any damage to the optic nerve. You may also have normal eye pressure but still have glaucoma.

Open-angle glaucoma can be hereditary

The disease can be hereditary. If you have a sibling or a parent who has open-angle glaucoma, you should regularly check yourself from the age of 50.

Mainly the elderly who get the disease

It is mainly older people who get the disease. It is uncommon to have it before the age of 50. 

There are two forms of glaucoma

Open-angle glaucoma is the most common form of glaucoma. There is also a more unusual form called acute glaucoma or narrow-angle glaucoma. Then you usually only get symptoms from one eye. The symptoms of acute glaucoma often come quickly and the eye hurts, runs and turns red. You can also get foggy eyesight and see colored rings around bright spots. It is also common to feel nauseous and vomit.

It is important that you receive treatment quickly in both forms of glaucoma so that you do not get a permanent visual impairment.

Both forms of glaucoma are serious eye diseases that can lead to impaired vision or blindness.

Getting a sick message

It can be overwhelming to be told that you have a serious eye disease. It is important that you have time to process the message. Get help and talk to your loved ones about what is worrying you. You can also talk to your doctor about wanting to see a curator.

It is common to be worried about being blind. Talk to your doctor if you feel worried about it. You can also get information from the doctor about where you can get help with visual aids and you can get a referral to a vision center if you need it. It is important to remember that most people with open-angle glaucoma do not become blind.

There is a well-developed organization at the vision center that can be helped. Here you can read about how it is possible to get visual aids , and find out which ones are available where you live.

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