Glaucoma


What is glaucoma?

Glaucoma is the second leading cause of blindness. Glaucoma is a complicated group of eye diseases in which damage to the optic nerve leads to progressive, irreversible vision loss. The optic nerve, located at the back of the eye, carries visual information to the brain. As the fibers that make up the optic nerve are damaged by glaucoma, the amount and quality of information sent to the brain decreases and a loss of vision occurs. 

 

There are many different types of glaucoma, but the main two include: 

  • Primary Open-Angle Glaucoma (POAG)

    • By far the most common type, primary open-angle glaucoma develops gradually and painlessly. Since there are no early warning signs, it can slowly destroy your vision without your knowing it. The first indication may only occur after some considerable vision loss.

  • Acute Angle-Closure Glaucoma (ACG) or Narrow Angle Glaucoma (NAG)

    • This results from a sudden blockage of the drainage channels within your eye, causing a rapid build-up of pressure inside your eye. This is a true eye emergency. 

  • Low Tesntion Glaucoma

    • This is optic nerve damage and peripheral vision loss wven with normal eye pressure. There may be circulation disorders affecting the optic nerve. ​

  • Secondary Glaucomas

    • These types of glaucomas may occur from eye surgery, eye injuries r swelling, cataracts, diabetesm or some medications. The eye's drainage meshwork can also become blocked by scar tissue, abnormal blood vessels, or foreiign objects, leading to increased pressure and optic nerve daage. ​


What are the symptoms of glaucoma?

The scariest thing about glaucoma is that this disease can steal your vision gradually and painlessly, without your noticing. The average patient needs to lose at least 50% of the nerve fibers before any problems are even noticed. And once these nerve fibers are destroyed, they can be be rehabilitated. 

Some people with glaucoma, especially acute angle closure glaucoma, do experience symptoms, but symptoms vary depending on the type and severity of the glaucoma. These patients can experience blurred vision, the appearance of colored rings around lights, extreme pain or redness in the eyes, and even nausea and vomiting. If not treated within 24 hours, ACG can cause blindness. Immediate medical care is required to preserve vision. This is a true eye emergency. If you have any of these symptoms, call our office immediately. 

As glaucoma remains untreated, people may miss objects to the side and out of the corner of their eyes. Without treatment, people with glaucoma will slowly lose their peripheral (side) vision. They seem to be looking through a tunnel. ver time, straight ahead vision may decrease until no vision remains. 

What causes glaucoma?
Some causes of glaucoma are known, others are not. Causes differ depending on the type of glaucoma. What we do know is that it generally cannot be prevented. 

 

The exact cause of open-angle glaucoma, where the drainage channels for the aqueous appear to be open and clear, is not known.

 

Closed-angle glaucoma can occur when the pupil dilates or gets bigger, blocking the drainage channel. An injury, infection or tumor in or around the eye can also cause internal eye pressure to rise either by blocking drainage or displacing tissues and liquid within the eye. A mature cataract also can push the iris forward to block the drainage 'angle' between the iris and the cornea. Nearsighted. 

 

Glaucoma can occur secondarily to a number of other conditions, such as diabetes, ocular injuries, or as a result of some medications like steroids.

For ACG, immediate drops may be adminisatered. The optometrist will keep you in the office until the pressures have semi-normalized. Oftentimes a laser prcoedure is required to sprevent this from occurring again. 


Who develops glaucoma?
It is estimated that over 2 millions Americans are being treated for glaucoma and millions more are unaware that they have the disorder. These numbers are expected to rise as the population gets older. 

Glaucoma most frequently occurs after age 40, but can occur at any age.

If you are of African or Hispanic heritage, you are more likely to develop open-angle glaucoma, and at an earlier age, than if you are Caucasian. Asians are more likely to develop narrow-angle glaucoma.

You have a higher risk of developing glaucoma if a close family member has it or if you have high blood pressure or high blood sugar (diabetes). There is also a greater tendency for glaucoma to develop in individuals who are nearsighted. Pts with thinner corneas. Increased IOP. 


How is glaucoma diagnosed?
Tests for glaucoma are part of a comprehensive eye examination at Visualeyes Optometry. A simple and painless procedure called tonometry measures the internal pressure of your eye. No puff of air here at Visualeyes! Ophthalmoscopy examines the back of the eye to observe the health of the optic nerve. A visual field test, a very sensitive test that checks for the development of abnormal blind spots, will also be performed here. If glaucoma is suspected, patients will be brought back to the clinic to have further testing performed. Once diagnosed, patients retunr to our clinic 2-4 times a year to have it monitored. 

Not all optometrists can treat glaucoma in the state of California, but ours can!  

Consultation

  • Case History

    • youroptometrist will weight all of the factors before deciding whether or not you need treatment for glaucoma. or whether you should be monitored closely as a glaucoma suspect. ​

  • Visual Acuity

    • This eye chart test measures how well you see at various distances. ​

  • OCT

    • This provides a computer-generated measurements of the retinal nerve fibers that join together to form the optic nerve. Damage to these fibers is extremely sensitive marker for glaucoma. This test allows a very accurate comparison of our retinal nerve fibers from year to year. 

  • Stereoscopic Photographs of the Optic Nerve

    • This provides three-dimensional photographs of the surface of your optic nerves to look for signs of damage from glacoma. ​

  • Ophthalmoscopy

    • this is a microscopic examination technique used to evaluate the optic nerves to look for signs of damage from glaucoma. Thisis best performed after pupil dilation. ​

  • Tonometry

    • An instruments measures the pressure inside the eye. ​

  • Gonioscopy

    • This is an inspection of the drainage area of your eye to determine if it is open, narrow, or closed. A special mirrored lens is used to view this structure. ​

  • Visual Field

    • This test uses white flashes of light on a white background to evaluate the peripheral vision in each eye. this allows detection of subtle changes to the vision of which you may not be aware and allows for monitoring of changes over time. ​

  • Short Wavelength Visual Field (SWAP)

    • This test uses blue flashes of light on a yellow background to evaluate the peripheral vision in each eye. in certain patients, this test may be more sensitive than a standard visual field test. ​

  • Pachymetry

    • This is a measurement of your corneal thickness. This test allows further interpretation of your intraocular pressure measurement. ​


How is glaucoma treated?
Left undetected and untreated, glaucoma can lead to permanent vision loss. The goal of the treatment is to prevent loss of vision by lowering the pressure in the eye. Immediate treatment for early stage, open-angle glaucoma can delay progression of the disease. That is why early diagnosis is very important. 

 

Prescription eye drops are the most common firsyt line of treatment. Thse must be taken regularly. Glaucoma is usually treated with prescription eye drops and medicines. The medications will either decrease the production of fluid in the eyes or work on the eyes structure to increase the outflow. Glaucoma medications can preserve your vision, but they may also produce side effects. You should notify our optometris if you thini you may be experiencing side effects. Side effects can include a stinging or itching sensations, red eyes or redness around the skin, a change in pulse and heartbeat, changes in energy levels, changes in breathing, dry mouth, changes in the sense of taste, headches, blurred vision, changes in eye color and eye dryness. In rare cases pills are used as well. If you have trouble with one medicine, tell our optometrists. Treatment with a different dose or a new drug may be possible. 

Never change or stop taking your medications wihtout consulting your optometrist. If you are about to run out of medication, ask your optokmetrist if you shouod have your prescription refilled. 

In some cases, surgery may be required to improve drainage. Laser treatments are applied to the area of the eye in which fluid drains out, increasing the ability for the fluid to flow out. Only one eye is treated at a time. While this surgery often works well, it is possible that uo will need more treatments.As you sit facing the laser machine, an ophthalmologist will hold a special lens to the eye. A high-intensity beam of light is aimed a the lens and reflected onto the meshwork inside your eye/. You may see flashes of bright green and red light. The laser makes several evenly spaced burns that stretch the drainage holes in the meshwork. This allows the fluid to drian better. Side effects can include inflamamtion. Drops will be needed after the surgery until the eye has healed. 

Conventioanl surgery makes a new opening for the fluid to leave the eye. This is usually performed after medicines and laser surgery have failed to control pressure. Surgery in operating rooms may also be required to create new channels for the aqueous fluid to leave the eye. This is anywhere between 60-80% chance of lowering pressure. This works best if you have not had any prior eye sirgeries, such as cataract surgery. Side effects with this include cataracts, problems with the cornea, and inflammation or infection inside of the eye. The buildip of fluid in the back of th eye may cause some patients to see shadows in their vision. If you have any side effects or problems, tell our office immediately. 

Stents are an option for patients with mild to moderate glaucoma. These are the world's tiniest medical devices that help in the drainage of the fluid in the eye, reducing the pressure without the use of drops in many cases. The stents are implanted at the time of cataract surgery. 

In some cases, low vision rehabilitation servies, which include the use of specialized optical devices and training, may benefit people with severe vision loss. 

 

What is the prognosis for glaucoma?
Unfortunately, any vision loss as a result of glaucoma is permanent and cannot be restored. This is why regular eye examinations are important.

Glaucoma cannot be prevented, but early detection and treatment can control glaucoma and reduce the chances 
of damage to the eye and a loss of sight!

If diagnosed at an early stage, glaucoma can often be controlled and further vision loss may beminimized. If left untreated, first peripheral cision and then central vision will be afected and blindness may result. 

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