instrumental focus

Data in a Flash

Device aids in retinal disease detection through photo-stress testing.

Joseph J. Pizzimenti, O.D., F.A.A.O.

A 34 year-old white male presented with sudden central vision loss OD that he said began one day prior. His best-corrected visual acuity was 20/60 OD, 20/15 OS. Suspecting macular disease, I turned to my diagnostic devices, starting with the latest addition, the MDD-2 (Macular Degeneration Detection) Macular Adaptometer, from Health Research Sciences.

Here, I explain why you should consider adding this device to your practice.

Overview

Research has revealed that measuring macular light flash vision recovery time can serve as an early indicator of macular pathology, or disease.¹

The MDD-2 Macular Adaptometer is a portable and handheld device that identifies the photo stress of the photoreceptors via a quantifiable measurement of the function of the macula. (Quantifiable measurements replace the need to re-examine images of macular tissue while looking for pathology.) The result: an objective, repeatable and reliable measure of macular pathologies and their progression through time, enabling you to gauge the success of a chosen therapy.

The MDD-2 Macular Adaptometer measures macular light flash vision recovery time, which has been shown as an early indicator of macular pathology, or disease.

Given the device's attributes, I use it on any patient I suspect has macular disease, such as age-related macular degeneration, macular holes, epiretinal membrane, diabetic macular edema, etc. In addition, the device is especially useful if your patient base is predominately age 50 or older or if you see a high volume of patients who have type 2 diabetes, as both patient populations are at high risk for macular disease.

Test procedure

To start, you or your technician lines the MDD-2 Macular Adaptometer's viewing aperture up to one of the patient's undilated eyes — the test is performed monocularly. (In my practice, we test the healthy eye first, as this is the “control” eye for comparison purposes.) Next, the operator instructs the patient to look into the viewing aperture and to align the “zero” image displayed to the center of their vision by adjusting the device's position accordingly. Then, the operator tells the patient to let him/her know once the patient has accomplished this. Now, the operator informs the patient that a bright flash is forthcoming, after which he'll see a digital numeral that he is immediately to announce to the operator. Once the patient tells the operator the number, the operator presses a button on the MDD-2 Macular Adaptometer, which displays a photo-stress measurement. The test takes a total of about five minutes.

A recovery time of approximately 12 seconds or less is considered normal. An increase of recovery time on successive visits or disparity between the two eyes may be an early indication of macular disease. That said, additional retinal disease diagnostic devices, such as optical coherence tomography, are needed to guide the practitioner to a definitive diagnosis.

Staff training

Health Research Sciences provides staff training in one of two ways: A sales representative visits with the doctor, or the company does a training call with the doctor's staff. In both cases, training lasts roughly 15 minutes, and then doctor and staff are invited to ask questions. Most of the training is focused on how to communicate with the patient to ensure a valid test. For example, sometimes, older patients have a hard time finding the “zero” in the back of the device and/or the new number post-flash. As a result, Health Research Sciences instructs new operators to constantly remind the patient to look straight into the back of the device.

Return on investment

With a start-up cost of $3,000 and a fee of $15 per test, you could expect to reach a return at 200 uses or after about three months if you see roughly four maculopathy suspects or patients a day. (Medicare and most major medical insurers do not reimburse for MDD-2 testing.)

Yet, the return on investment on the MDD-2 Macular Adaptometer goes beyond the immediate financial return for its purchase. Because the device aids in the early identification, timely treatment and, ultimately, less vision loss for patients, it easily leads to referrals from patients who are both grateful for and impressed by the device.

Outcome

The MDD-2 Macular Adaptometer measured a recovery time of 20 seconds OD and nine seconds OS in the patient mentioned above. This indicated a high suspicion for maculopathy. In addition, dilated fundus exam revealed central serous chorioretinopathy OD, and OCT showed localized serous detachment of the sensory retina.

I monitored the patient's condition with the device during monthly visits for the subsequent six months. Due to minimal improvement through this time, he received photodynamic therapy (PDT) with medication. Following treatment, the patient improved to 20/20 OD and demonstrated an MDD-2 Macular Adaptometer result of 11 seconds OD.

Because of the MDD-2 Macular Adaptometer, I was able to narrow the possible diagnosis very early in the eye exam. It also gave me a way to document visual function before and after treatment, validating the success of PDT. This situation — and others like it — is why I rely on and highly recommend this device for the early detection and monitoring of prevalent macular diseases. OM

1. Newsome, DA. Negreiro M. (2009). Reproducible measurement of macular light flash recovery time using novel device can indicate the presence and worsening of macular diseases. Curr Eye Res. 2009 Feb;34(2):162-70.