The C-shaped approach is a combination of the medial and the preseptal or retroseptal transconjunctival approaches with a lateral canthotomy incision. The C-shaped incision permits a periorbital dissection over a 270 degrees panorama, ie, the entire medial wall, the orbital floor, and the lateral wall up to the zygomaticofrontal suture. The C-shaped incision/approach can start from any of the incision lines. It is most convenient to begin with the lateral canthotomy and the inferior cantholysis, because this facilitates the preseptal inferior fornix transconjunctival dissection and its transition into the medial orbit. This is enabled by swinging of the lower eyelid into an anterior and inferior position.
The following anatomic series shows the exposure achievable with the C-shaped incision. It is not possible to view all orbital sites at the same time as shown in the previous illustration. The retractor has to be moved to visualize the individual bony portions.