In operative treatment of glaucoma, the OS 4 has created significant added value in micro-invasive glaucoma surgery (MIGS). High Frequency Deep Sclerotomy (HFDS) ensures excellent long-term results and has an extremely low complication rate, and short intervention time.


HFDS stands for High Frequency Deep Sclerotomy. In micro-invasive glaucoma surgery (MIGS), HFDS creates direct access from the anterior chamber to the Schlemm’s canal and further into the sclera. The resistance of the trabecular meshwork is thus bypassed. The abee glaucoma tip is inserted through 1.2 mm paracentesis and, by means of diathermy output, it creates six small sclerotomy pockets in the iridocorneal angle, ensuring improved outflow of aqueous fluid.

HFDS can be used individually and can also be ideally combined with cataract surgery. HFDS is characterised by a very short intervention time. Bleb formation is prevented, and so is fibroblast movement to the sclerotomy. Moreover, there are no corneal scars. Oertli’s High Frequency Deep Sclerotomy boasts excellent long-term results. If required, a further HFDS intervention can be made to optimise results.

Advantages of HFDS

  • Ideal in combination with cataract surgery or as individual application
  • Very short intervention time
  • Excellent long-term results
  • No bleb-formation, no corneal scars
  • Surgery can be repeated
  • Very low complication rate

Instruments and accessories


Diathermie hand piece, reusable
VE201710 Hand piece long, „plug-on“ diathermy, cable 3 m, floating connector (black)
VE201712 Hand piece short, "plug-on" diathermy, cable 3m, floating connector


HFDS Glaukom-Plug-On-Tip, reusable
VE201751 abee® glaucoma tip, ab interno, High Frequency Deep Sclerotomy



Do you want to find out more about it?

Cataract surgery

Thanks to Oertli innovations such as easyPhaco and HF capsulotomy, cataract surgery can be performed more quickly, safely and calmly than ever before.


Vitreoretinal surgery

In vitrectomy surgery, the OS 4 brings about superb results thanks to the well-thought-out fluidics concept and innovative instruments.

MORE about vitrectomy