Line Segmentation Errors on Heidelberg OCT

Wed, 3 Apr 2024 22:03:12 GMT

We've been having issues with the line segmentation being incorrect on our Heidelberg OCTs. The issue persists across multiple cameras, is not do to low quality scans or thinning that makes the BM almost impossible to determine. We've contacted Heidelberg Engineering and they aren't familiar with that issue:

Pre-correction (ART 19 Q:21)

Post "Automatic" correction in "Segmentation Editor"

Second Example:

Pre-correction (ART 17 Q:22)

Post "Automatic" correction in "Segmentation Editor"

Also, sometimes our main OCT's standard focus distance is off, either too near or far. I'll need adjust the focus point to L or even XL to get the image lined up properly, then sometimes I need to drop down to S. We've had the internal fixation light straightened but that just fixed where patients were looking and not this focus issue.

Has anyone run into either of these issues?

Thu, 4 Apr 2024 14:32:20 GMT

Yes, please post some images if you can.

Did you have any instances of this happening on the same patient and on the same day taken using more than one of your Spectrali?

Thu, 4 Apr 2024 17:08:19 GMT

By the time the images have loaded the patient is usually with the tech that preps them for the MD, at that point we've been using the auto segment editor or I'll manually edit before creating reports. No, we haven't redone images on a different or the same Spectralis. We will try to capture a second image when have a chance.

Thu, 4 Apr 2024 17:46:02 GMT

In my opinion, these are minimally acceptable scans due to a weaker than ideal signal strength. That weaker signal can throw off the software's ability to place segmentation lines.

Also, do you typically place your b scans that high in the window, or are these images just cropped that way?

My hunch is the signal strength need to be improved, once you determine what's weakening the signal.

Thu, 4 Apr 2024 18:37:53 GMT

What signal strength would you say is acceptable? The issue became noticiably worse over the last 6mo and we hadn't changed anything as far as how we take images leading up to that point.

For the most part the diminished signal is patient related (cataracts, corneal issues, vitreous haze). Is it possible or have you observed anything internally with spectralis that causes a low signal? Can I manually increase that signal without increasing the ART for our MAC standard (49 line, 20x20,ART 16 frames)?

The images are cropped, I place my images with the BM just above the middle of the center of the B Scan live image and try to keep them there.

Fri, 5 Apr 2024 15:15:20 GMT

Are you using an OCT 1 or OCT 2? To me that looks like OCT 1, which has less detail than OCT 2, but those quality numbers on OCT 1 are doing fine. An OCT 2 giving that view would be a different story.

Is the lens clean? When I say clean, I mean, turn off the lights, turn on a small flash light, hold the flash light almost perpendicular to the lens and inch or two away from it, and see if there are smudges. Oil from hands and noses are hard to see otherwise, but if you have smudges that appear while doing this, cleaning the lens will improve your signal and clarity.

What version of software are you using? Are you on HEYEX or HEYEX 2? Some older versions of the original HEYEX software didn't perform segmentation as judiciously as newer versions, so that can be a factor sometimes.

There can be rare things that impact scan quality, but usually if it's internal to the camera it pulls up an error of some kind letting you know the signal quality has dropped. We have had that issue with one device due to a thunderbolt adapter that was causing issues. After getting the thunderbolt cable replaced from needing the adapter to not needing the adapted that issue stopped. It was a dramatic issue, to the point the camera wouldn't provide a view in the OCT, then the Fundus would drop out.

Fri, 5 Apr 2024 15:25:48 GMT

Thanks for your suggestions!

We are using OCT 2's and are running HEYEX 2. We had some issues with the thunderbolt cable that caused our computer to crash, we replaced the PC and haven't had that issue since. Likely I'm expecting perfection where I can't attain it.

We regularly clean the lenses and they are clear right now. What do you use to clean your lenses? I've requested our admin budget for a lens cleaning kit but didn't get approved, I might just get my own kit. Any recommendations?