Frequently Asked Questions
Find the answers to frequently asked questions about age-related macular degeneration, dark adaptation and AdaptDx® testing. If you don’t see the answer you need below, contact us here.
AMD and Dark Adaptation
What is dark adaptation?
Dark adaptation is the ability of our eyes to adjust from light to darkness. Learn more about dark adaptation here.
What is Rod Intercept (RI)?
Rod Intercept is the amount of time it takes for eyes to adapt to darkness. It is measured in minutes using the AdaptDx automated dark adaptometer. If a patient’s RI is below 6.5 minutes, the patient has normal dark adaptation function. If the RI is equal to or above 6.5 minutes, the patient has impaired dark adaptation.
What is the connection between AMD and dark adaptation?
Research has shown that impaired dark adaptation is the first biomarker of AMD and indicates subclinical AMD at least three years before structural changes are visible with imaging or clinical exam. Learn more about the science behind dark adaptation testing here.
What is subclinical AMD?
Subclinical AMD is the earliest stage of the disease. Even though no structural changes can be observed at this point, AMD has already impaired the function of the macula, specifically the dark adaptation function. Learn more about subclinical AMD here.
What is the value in detecting AMD at a subclinical stage?
AMD has an extended subclinical phase lasting five years or more. During this time there is little or no loss of vision, but it is followed by a precipitous loss of vision if a patient transitions to an advanced stage of the disease. Detecting AMD at a subclinical stage will allow eye care physicians to help patients take proactive measures that can slow progression of the disease.
How accurate is dark adaptation testing using the AdaptDx?
AdaptDx is 90.6% sensitive in identifying AMD cases and 90.5% specific in identifying normal cases. The overall accuracy of 90.6% makes AdaptDx more accurate than a visual field test. Read more about the sensitivity and specificity research here.
Compare AdaptDx to Other AMD Tests
How is AdaptDx different from other AMD testing tools?
Other devices and tests look at structure of the macula (OCT, fundus photography, etc.) or risk factors of AMD (contrast sensitivity, macular pigment optical density, genetics, etc.). AdaptDx is the only device that measures the function of the macula and provides objective and easy-to-interpret results. Learn more about AMD testing here.
What is the difference between AdaptDx and the MPOD?
MPOD (macular pigment optical density) devices measure a risk factor for AMD, not a physiological indicator of the disease. The AdaptDx dark adaptometer measures a biomarker of the disease with 90% specificity and sensitivity. Impaired dark adaptation results from an AdaptDx test signal that AMD is already present. Research has shown that there is no correlation between low MPOD levels and impaired dark adaptation.
Unlike MPOD devices, AdaptDx testing is reimbursable under CPT code 92284 at a national average of $64.08.
Testing with AdaptDx
Is the AdaptDx testing reimbursable?
Yes. The CPT code for dark adaptation testing is CPT 92284 and reimburses at a national average of $64.08. There are also numerous applicable ICD-10 codes, including H53.62 for acquired night blindness.
Who should take the AdaptDx test?
The AdaptDx test is indicated for patients with symptoms or risk factors. It is also used to monitor disease progression.
Patients with issues seeing or driving at night:
Since a night vision problem is the first symptom of AMD, all patients who have issues seeing or driving at night should be tested for dark adaptation impairments. Acquired night blindness (ICD-10 H53.62) is a billable reason for performing a dark adaptation test (CPT 92284)
Patients who are at risk of AMD:
Patients over 50 who are at high risk of developing AMD should be tested on an annual basis, even if they do not experience night vision problems. Risk factors include age, family history, smoking, obesity and overall cardiovascular health (heart disease, high blood pressure or high cholesterol).
Patients with AMD to monitor disease progression:
Patients with diagnosed AMD should take the AdaptDx Extended Test every six months or more to monitor disease progression. There are several ICD-10 codes that can be used to justify an extended dark adaptation test.
Are there any risks in taking the dark adaptation test?
No. The test is non-invasive, which means that nothing touches the patient’s eye. The lights used are very dim. Even the conditioning flash at the beginning of the test is milder than a normal camera flash.
How do I phase the AdaptDx testing into my practice workflow?
Every eye care practice is different and the way you’ll incorporate the AdaptDx testing into your workflow depends on your current practice for specialty testing. As part of the AMD Excellence Program, our team of experienced Practice Management Consultants will work with you to integrate the AdaptDx test into your existing flow and optimize it to reach your goals.
Should I use trial lenses to perform a test with the AdaptDx?
You may use trial lenses, but it is not required. The use of trial lenses may aid patient comfort. If you have software version number 4.4.0 or later, enter the distance correction into the trial lens field on the test screen and the AdaptDx will calculate the suggested trial lenses.
Should I test both eyes?
Since AMD is a bilateral disease and there is a 92% concordance of dark adaptation status between eyes, the AdaptDx can be used unilaterally in both the Rapid Test (for disease detection) and Extended Test (for disease staging and monitoring) protocols. Some eye care professionals alternate eyes from test to test. For reimbursement, CPT 92284 can be used whether one or both eyes are tested, without the use of code modifiers for laterality.
Interpreting AdaptDx Results
How do you interpret AdaptDx results?
The AdaptDx test results are objective and very easy to interpret. By looking at a single number on the test report (the Rod Intercept or RI), you will be able to determine whether the patient has impaired dark adaptation.
- An RI below 6.5 minutes indicates normal dark adaptation function, consistent with normal retinal function.
- An RI equal to or above 6.5 minutes indicates impaired dark adaptation, consistent with AMD.
Do cataracts affect the AdaptDx test results?
No. Dark adaptation measured by AdaptDx is not affected by cataracts.
Does amblyopia affect the AdaptDx test results?
Amblyopia does not affect the test results because it is not correlated with AMD. The results will not be affected as long as the patient is capable of fixating on the light and can concentrate.
Does color vision deficiency influence the results of an AdaptDx test?
Color vision deficiency has no impact on dark adaptation test results. The only special consideration would be to precisely explain the test without reference to the color of the fixation target and stimulus light.
The AdaptDx has been a great addition to my office. This device allows me to find patients with AMD much sooner than we've ever been able to do. We know that 1 out of 3 Americans over the age of 75 has some form of AMD. But why wait until it's obvious to start therapy?