Having an objective lab test to assist in the diagnosis and management of Dry Eye Disease (DED) can make clinicians’ as well as patients’ lives a lot more enjoyable. Imagine trying to manage diabetes without a test! Here are a few tips that can help in implementing the TearLab Osmolarity System into your practice.
TearLab Osmolarity System has one of the lowest Coefficient of Variation (CV) values of any point-of-care in vitro diagnostic device having FDA clearance. It is more than twice as accurate as instruments used at point-of-care for glucose and cholesterol. Partly because of this achievement, the TearLab was awarded a Medical Device Excellence Award for its superior in vitro diagnostic design.
The TearLab Osmolarity System is extremely accurate and precise. Each of the three components listed below is highly sophisticated and integrated to produce an accurate osmolarity reading.
1-Disposable Microchip
2-Pen
3-Reader
Disposable Microchips: TearLab tests each batch of cards three times before they leave the factory and again just prior to shipping them out to the field.
Despite this level of quality control, the TearLab Test Cards are sensitive medical devices and can get damaged during shipping. To ensure your osmolarity results are reliable and accurate when you receive shipped product, TearLab has developed the following steps to insure that your cards have not been damaged during shipping.
The glass saline Control Solutions determine if the test cards are functioning within specifications following shipment. Running control solutions on a new shipment of cards verifies the test cards have NOT been damaged in transit between our factory and the end user – they are constructed out of medical grade gold layered on soft plastic, which are susceptible to melting under significant heat. (Note: The only time the test cards are outside of a controlled environment and could be damaged is during shipment to the end user. The company provides two free cards in each box for this quality control step).
In research settings, most run control solutions each day that patient samples are taken however the frequency of control solution testing is determined by the study protocol and not the manufacturer.
Pen+ Reader Accuracy: To further insure confidence of the operating efficacy of the TearLab system, the Electronic Check Cards (ECC) test insures that the pen and reader are operating properly. The Blue Electronic Check Cards (ECC) are to be used each day prior to the first patient is tested. The ECC verifies the Pen and Reader are within exact specifications. This is a similar to calibrating a Tonopen, for example. If you leave the system turned on 24/7, this is the only requirement on a daily basis. (Note: never use the Blue ECCs with control solution or patients.)
When initially testing patients, it is important the patient has had no therapeutic drops instilled for at least 2 hrs prior to testing as this may result in a lower osmolarity finding. Many users have found scheduling a dedicated dry eye workup to insure no drops have been used and ensuring an accurate osmolarity test result.
When using TearLab in managing treatment efficacy, we have found that changes in osmolarity typically precede changes in symptoms, and if you see a patient’s number come down with treatment, in a few months they typically report feeling much better. Conversely, we have seen that if their number is unchanged or even goes up with treatment, either it’s time to modify the treatment or inquire if they are compliant with therapy e.g. drops or oral meds.
Interestingly, in a recent 12-month Phase IV study across 25 practices consisting of both ophthalmologists and optometrists, the TearLab was shown to have a remarkable impact on improving patient education and compliance 97.9% of the time. Because dry eye can be a variable and frustrating experience in the clinic, it’s quite a luxury to have a number you can rely upon.
If users follow these guidelines, they can comfortably rely in their osmolarity reading. TearLab is a valuable laboratory device that gives an objective measure of osmolarity that has been proven to be nearly 90% predictable of dry eye disease. This is especially helpful when patients have symptoms mimicking DED and helps clinicians consider other potential diagnoses. This can reduce a “default diagnosis” of dry eye, which occurs rather frequently without having an objective test such as TearLab.
