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Summary of Use


     MacDx® measures the recovery time of the photoreceptors after light exposure, an estimate of retinal health. The app fulfills the need for early discovery of macular disease by using one’s own device, iPhone, iPad, or iMac, the first step for seeking professional eye care for macular disease. MacDx® complements tests given by eye care professionals and does not replace any part of their usual eye examination. MacDx® does not diagnose or treat eye diseases, it identifies those with delayed recovery of the macula to light, a sign of possible disease.  MacDx® can be used remotely by individuals or in the office by eye care professionals. 

    White-light Dark Adaptation is the screening test of the app. After viewing a light on the screen an iPhone, iPad, or iMac, a dark spot appears in the central of vision, the moment this dark spot fades to become whiter or brighter than a surrounding annulus of a bullseye is the recovery time, recovery time is known to increases with age and some diseases. The length of the recovery time can help the eye care professional in diagnosing disease. Endpoint consistency is critical and is measured by CV% (coefficient of variation), a value appearing in the results. It is recommended to repeat testing until acceptable consistency is achieved (CV% less than 20% in a series of 4 tests). If consistency is not initially achieved, retest. Self-referral to an eye care professional is recommended when the recovery time is consistently greater than 20 seconds in one or both eyes. When the recovery time is greater than 20 seconds, retest at a different time to confirm the result. The eye care professional will determine if macular disease is present. The app is automated which allows local or remote testing with immediate analysis of the results. Instructional audio in English and Spanish is embed in the app. In addition to White Dark Adaptation, Color Light Adaptation and Dark Adaptation Curve are included for in-depth analysis (See updates at for more information).

     Special features: (1) Entering and archiving visual acuities, general diseases and eye diseases during registration or prior to “Finish & Save”, (2) Terminating false starts by tapping the “Stop” link on the left of the screen and then tap “Restart”, (3) Previewing a test result by observing the seconds appearing in the lower right corner near the hand following each endpoint, (4) Recalculating results to eliminating outliers and erroneous endpoint, tap QR icon on home page to access “Updates page” of, download Numbers calculator, then manually enter the acceptable endpoints from the test results and (5) Sending results by email, tap the envelope at the top of Results.

     The testing time for White-light Dark Adaptation Test is about 5 minutes. Test in a semi-dark room: the room should be sufficiently dark such that you should not be able to see the reflection of your face in the screen. The normal recovery range is reported to be up to 20 seconds.  Results are only valid if the test is performed consistently as measured the CV%, which needs to be less than 20%.  If the recovery time is 12 seconds and CV% is 5% the result accepted and is within normal limits.  However, if the recovery time is 12 seconds and the CV is 30%, the result is inconsistent and rejected, testing needs to be repeated.  For example, a result qualifying for referral to an eye care professional would be recovery time greater than 20seconds in one or both eyes and the CV% of less than 20%, which means the test was accurately performed but the recovery time is over the normal limit. Not all recovery times over 20 seconds will be abnormal, this will be determined by the eye care professional. The QR logo on the home page links to where the latest updates are available.

     For Color Light Dark Adaptation Test there are 2 options.  A: Test with the same color light repeatedly or B: Test with white, red, green, and blue light sequentially.  Clinical data is being collected and the normal range will be posted on the update page at

     For Dark Adaptation Curve Test white light is used and the exposure times are 15, 30, 60 and 90 seconds.  Clinical data is being collected and the normal range will be posted on the update page at

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