I was curious to see how good or bad these OTC otoscope models are compared to the Welch Allyn otoscope I use. Here are the models I decided to use for comparison (as seen on Amazon.com).
Using a standardized tiny print "C E" sticker, I checked out these models and took a picture of the image as shown below:
|Dr. Mom Slimline Pocket Otoscope (3rd Generation)
|Professional Diagnostic Otoscope Kit|
|Welch Allyn Otoscope|
Overall, the images can be seen clearly and when I tried it out on a human being, the eardrum can also be similarly be assessed.
However, there were two main factors that make the Welch Allyn the superior otoscope compared to the much cheaper OTC models.
The viewing window is MUCH larger on the Welch Allyn allowing one to see into the "corners" of the ear canal that one would have to physically manipulate with the other models. Check out the picture showing the viewing windows side-by-side. #1 is the Dr. Mom, #2 is the Pro Kit, and #3 is the Welch Allyn.
The second factor that makes the Welch Allyn superior is the MUCH greater distance where the image (eardrum) remains in focus. The Welch Allyn can maintain a focus on the eardrum from 3cm away whereas the OTC models is half that (1.5cm). Why is that important?
It's because not all ear canals are the same size and length. So when one inserts the otoscope into the ear, the OTC models MUST be within 1.5cm of the eardrum (you have to stick the otoscope far enough into the ear canal such that the tip is within 1.5cm from the eardrum) otherwise, the image will be blurry. Some patients may not tolerate the otoscope being inserted that far into the ear canal.
With the Welch Allyn, the eardrum can immediately be seen and in focus from 3cm away from the eardrum (you don't have to stick the otoscope as far into the ear canal in order to see the eardrum clearly in focus).
So there you have it...
The OTC models can be used successfully with an image as good as the Welch Allyn model as long as two factors are met.
- You MUST insert the otoscope far enough into the ear such that the tip is at least within 1.5cm from the eardrum.
- Due to the smaller viewing window, you have to have the otoscope precisely over the eardrum.