THE PARAOPTOMETRIC – MAY 2016

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The Konan Amsler app from Konan Medical USA, Inc.
helps patients with AMD track any changes to their eyesight.

Amsler Grid: What it is, What it Shows, and How to Perform the Test. Plus, additional ways doctors detect age-related macular degeneration

The Amsler Grid is a vision-monitoring tool made up of black vertical and horizontal lines on a white background with a central fixation dot. The test, developed by Swiss ophthalmologist Marc Amsler, identifies retinal pathology in the central portion of vision in each eye due to age-related macular degeneration (AMD).

There are two types of AMD, wet and dry. Most patients who are diagnosed with AMD have dry AMD, the early stage of the disease.

HOW THE TEST SHOWS AMD
The patient looks at the grid pattern and records whether any of the lines appear crooked, bent or distorted. Abnormal results are indicative of AMD.

PERFORMING THE AMSLER GRID
Here are six steps to perform the Amsler Grid test.
1. The Amsler Grid test should be performed in a room with good lighting.

2. The patient should be instructed to put on current correction. If the patient is wearing bifocals, the patient should be instructed to look through the bottom portion of their glasses.

3. The patient should cover one eye and hold the grid test card approximately 14 to 16 inches from their face.

4. As the patient looks at the central dot, they should be instructed to identify any area on the grid where the pattern is missing, looks wavy, blurred or distorted. Ask the patient:
•”While staring at the dot, are you able to see the entire box? Are any corners missing?
•”Are there any wavy lines and missing areas of the grid?”

5. If patient indicates “Yes” to any of the above questions, have them mark or highlight the abnormal areas.

FOUR MORE WAYS AMD IS DETECTED
The doctor may also perform these tests:

•Dilated Fundus Exam. Dilation of the pupil will allow better view of the retina, so the doctor can better assess the patient’s retina for damage.
•OCT (Optical Coherence
Tomography).
This test captures a high resolution cross section of the retinal layers and can provide detail of the damage caused by macular degeneration.
•Fluorescein Angiography. Fluorescent dye injected in the vein travels through the blood vessels of the eye while still photographs are captured of the fluid flow. Any areas of swelling or leaking vessels are easily seen through the camera’s specialized filters.
•Dark Adaptation. This test measures how long it takes the retina to adjust from bright to dim light. A slower response time may indicate early AMD.

6. Repeat the test on the other eye.

The patient can also be instructed to self-test at home, either using a test card or an app. The frequency of testing is recommended by the doctor, and the patient should be instructed to make an eye appointment if they experience any visual changes. Patients already diagnosed with advanced wet AMD should be instructed to check the grid every day for changes. Upon first use of the Amsler Grid, the patient should note and document all current areas of distortion, wavy or missing lines. For each subsequent day of testing, the patient should compare each new test to the baseline test. If any new areas of distortion, wavy or missing lines appear, the patient should contact their eye doctor for an appointment.

Janet Hunter, COMT, president of Eye Source, LLC, specializes in ophthalmic technician training.

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