# Cannot open TopCon OCT (.fda) file on Slicer

**URL:** <https://discourse.slicer.org/t/cannot-open-topcon-oct-fda-file-on-slicer/30718>\
**Category:** Support\
**Tags:** oct\
**Created:** [July 20, 2023, 10:21pm UTC](https://discourse.slicer.org/t/cannot-open-topcon-oct-fda-file-on-slicer/30718 "2023-07-20T22:21:10Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![mburaozkan.mz](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mburaozkan.mz](https://discourse.slicer.org/u/mburaozkan.mz)\
**Post date:** [July 20, 2023, 10:21pm UTC](https://discourse.slicer.org/t/cannot-open-topcon-oct-fda-file-on-slicer/30718/1 "2023-07-20T22:21:10Z")

</div>

I am trying to open Topcon .fda file but I just can’t cause it gives me no error at all just:

…/192784.fda - load failed

Is there anything I need to do before upload the file?  
other than that I just followed the documentation but there was nothing about this problem.

Also slicer works with other image files so there is no problem that I see other than topcon .fda file.

---

<div class="post-metadata">

**Author:** ![mburaozkan.mz](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mburaozkan.mz](https://discourse.slicer.org/u/mburaozkan.mz)\
**Post date:** [July 20, 2023, 10:21pm UTC](https://discourse.slicer.org/t/cannot-open-topcon-oct-fda-file-on-slicer/30718/2 "2023-07-20T22:21:31Z")

</div>

I am trying to use .OCT files and I find one extension for this SlicerOCT extension but when I checked the extension I couldn’t find it. is it removed? And if so is there any extension that I can use for .OCT(A) types of files?

---

<div class="post-metadata">

**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [July 21, 2023, 2:21pm UTC](https://discourse.slicer.org/t/cannot-open-topcon-oct-fda-file-on-slicer/30718/3 "2023-07-21T14:21:06Z")

</div>

According to the [documentation](https://slicer.readthedocs.io/en/latest/user_guide/data_loading_and_saving.html), TopCon .fda files can be read after you install the Sandbox extension.

[SlicerOCT extension](https://iovs.arvojournals.org/article.aspx?articleid=2557818) has never been submitted to the Slicer extension catalog. You can contact the authors of the paper about how to get access to that extension. Let us know what you find out.