What is Glaucoma?
Glaucoma is a disease of the eye that is created by an imbalance in the flow of fluids in and out of the inside of the eye. We are not talking about the tears that bathe the outer portions, but the internal fluids within the globe. The body is constantly producing fluids to bathe our tissues to keep them healthy. In the eye, fluids are produced, but they must also exit to keep a constant flow or the internal pressure of the eye will build up. In the most common form of glaucoma, eye pressure elevates because fluids are produced too fast or they drain too slowly, or both. Other rarer forms of glaucoma can occur in eyes that have lower pressure. An eye with glaucoma experiences damage to the delicate tissue in the back of the eye called the optic nerve, potentially leading to loss of peripheral vision and ultimately all vision. Fortunately, in the United States, going blind from glaucoma is extremely rare, as doctors have extensive testing available to screen for the disease.
Testing for glaucoma by your eye doctor is not what it used to be. Doctors have learned so much about the disease in the past ten years, realizing that an eye pressure test is not enough to make a diagnosis. You will read below about the tools that are used today to screen for and aid in the diagnosis of glaucoma.
Testing Used to Diagnose Glaucoma
Eye Pressure and Glaucoma
Tonometry is the name given to the eye pressure test. There are many types of tonometers. Available since the mid 1970’s, most people have experienced the “air puff”. This type of tonometry is called non-contact, as no instrument touches the eye and no topical eye drops are used for anesthesia. This has historically been a great screening tool but there are more accurate tests available today. Other archaic tests were available for many years prior. One test that has endured since the 70’s is called Goldmann tonometry and is considered the standard of care today. To do Goldmann, the doctor uses a blue light and a small highly polished instrument attached to a microscope (called a slit lamp) to gently touch the front surface of the eye (the cornea). This effectively checks the eye’s pulse and internal pressure. Other instruments used today use a similar philosophy as Goldmann and are usually done by a technician, prior to seeing the doctor. Two of these tonometers are called ICare and Tonopen. They have proven to beextremely accurate and may be the only tonometer that an optometrist office uses.
OCT – Optical Coherence Tomography
OCT, or Ocular Coherence Tomography, is a highly sophisticated device used as both a screening tool for early diagnosis and as a more in depth analytical tool for those that have the disease. In our office, our technicians perform what is called the IWellness exam as part of our preliminary work up, using our OCT. Somewhat like an MRI without the noise and taking only a few seconds, this instrument looks at the optic nerve and other tissues of the retina on a cellular level. This instrument helps doctors spot diseased cells years before they might have otherwise been able to do so in the past.
Visual Field Perimeter
A Visual Field exam is used to check peripheral vision. Since glaucoma affects mid-peripheral and far peripheral vision before affecting central vision, this test can detect signs of damage in those areas. It is now known, however, that once the doctor finds that you have lost any peripheral vision, you have likely had glaucoma for years that has gone undiagnosed. In the past, the OCT and other sophisticated instruments were not available to detect early damage like we can today
Retinal photography is another tool that is used for screening and management of glaucoma. A photo is taken of the internal portion of the eye, making it easier than ever before for the doctor to view and analyze the optic nerve and retina tissues.
A Pachymeter is used to measure the thickness of the cornea. It is known that patients who have thinner corneas are at a high risk of developing glaucoma.
Other risk factors for glaucoma include age, ethnicity, smoking, obesity, hypertension, diabetes, sleep apnea, people with cataracts, and family history. African Americans have a higher risk factor for glaucoma than the general population.
Can Glaucoma Be Treated?
Treatment comes in many forms and is highly individualized. Depending on the risk factors, many doctors choose to examine the eyes periodically, just observing for any changes. If there are no changes, there is no reason to treat. If the choice is to treat, the first line of direct treatment is the use of eye drops, the intent being to lower the pressure in the eye. Different eye drops act in different ways. Some reduce the fluid produced internally and others increase the outflow of fluid. Sometimes, multiple medications are needed to reduce the pressure significantly enough to reduce the chances of damage to the optic nerve. Modern glaucoma medications tend to be very expensive. It is common in our office to have to fight with insurance companies to pay for the more up-to-date glaucoma medications. Surgery is another way to treat glaucoma. There are many different types of glaucoma surgery and as with any procedure there are risks. It is best to consult with your optometrist or ophthalmologist to see which treatment regimen is your best option.
Glaucoma testing and treatment is a forever developing science. For healthy individuals at any age, It is best to have your eyes screened annually with a comprehensive eye examination. For those with glaucoma, every 3 to 6 months is recommended depending on the severity. Our team of professionals at Optix Family Eyecare is always available to answer any questions you may have. You can contact us at 516-931-6330 or email us at firstname.lastname@example.org. Schedule an Eye Exam today. Check us out on Facebook and follow us on Twitter.
Joel Kestenbaum, OD