Macular Degeneration

Macular degeneration is the leading cause of legal blindness, affecting more Americans than cataracts and glaucoma combined. Macular degeneration occurs most often in people over 60 years old, in which case it is called Age-Related Macular Degeneration (ARMD).

Macular degeneration is caused by the deterioration of the central portion of the retina, the inside back layer of the eye that records the images we see and sends them from the eye to the brain. The retina's central portion is the macula and is responsible for fine vision tasks. It controls our ability to read, drive a car, recognize faces or colors, and see objects in detail. Because only the center of your vision is affected, people will not go completely blind from the disease.Peripheral vision is maintained allowing relatively normal movement and activities aside from those requiring fine detail such as reading.

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There are two forms of ARMD. The 'dry' type affects about 90 percent of those with the disease. It progresses more slowly. 'Wet' ARMD is the second type. Although only 10 percent of all people with ARMD have this type, it accounts for 90 percent of all severe vision loss from the disease. Damage in the wet type is caused by new blood vessels behind the retina that leak blood and fluid under the macula.

Age, family history, smoking, poorly controlled diabetes, and high blood pressure are significant risk factors in ARMD.

People in their 50's have about a two percent chance of getting ARMD, while people over 75 have a 30 percent chance.

Neither dry or wet ARMD causes any pain. The most common early symptom of dry ARMD is slightly blurred vision. The first sign of wet ARMD is that straight lines appear wavy, though at this point there may already be significant damage. Maintaining regular eye examinations is the best way to detect ARMD. The eye care professional can use visual acuity tests, field screenings, and dilated fundus examinations to look for ARMD. Those at high risk for ARMD related vision loss can control some of the risk factors mentioned above. Nutritional supplements for ARMD vary greatly and only a few are high quality such as the Science based Health products. For those who have experienced vision loss, high powered glasses, separate magnification devices and even electronic aids can restore reading vision. Dr Tronnes is Southern Oregon’s leading expert in these technologies and has helped many of our ARMD patients regain significant visual function.


Weston Eye Center is a pioneer in developing technologies for early detection of Wet AMD such as the PHP (Peripheral Hyperacuity Perimetry test). Along with our retinal consultants we can provide increased likelihood that vision can be preserved.

For more information on ARMD, there are several other web sites available. These include the American Macular Degeneration Foundation at, the Macular Degeneration Foundation at, and the National Eye Institute at


New Home Monitor for AMD Patients

 In keeping up with the latest technological advances and in striving to deliver better patient care, we are very excited to offer the ForeseeHome AMD Monitoring Program. This is the home version of the PHP test described above which our office helped develop.

The ForeseeHome AMD Monitoring Program provides frequent monitoring of patients at risk of developing wet AMD.  By providing monitoring from a patient’s home, the program links patients and doctors between eye exams.  Moreover, the ForeseeHome Monitoring program provides live, ongoing monitoring and alerts of significant changes in vision.


If you have been diagnosed with age-related macular degeneration, call 541-672-2020 and schedule a doctor consultation to determine if you are a candidate for the ForeseeHome AMD Monitoring Program.


For more information about the ForeseeHome AMD Monitoring Program, visit

Amsler Grid Home Test

This test is an indicator of wet macular degeneration where damage to the macula has already begun. Those at high risk for the development of wet AMD should not rely on the amsler grid, rather they should be examined more frequently and have preferential Hyperacidity perimetry (PHP) testing to increase the chances that treatment to preserve vision will be successful.


  • Wear your reading glasses
  • Hold the Amsler grid at a normal reading distance
  • Cover one eye
  • Look at the dot in the center of the grid
  • Note how the lines and squares appear
  • Test the other eye in the same manner


All of the lines should be straight and the squares of a uniform size.

If you note any changes in the appearance of the grid, such as distortion, blurring, discoloration, dark or missing areas of the grid, or any other changes, call and see your eye doctor immediately. Do not wait to see if the changes will clear on their own. Timely treatment is vital to safeguarding your vision.