HFDS® for modern MIGS surgery

In operative treatment of glaucoma, the mobile surgical platform CataRhex 3 allows for even greater safety and efficiency in micro-invasive glaucoma surgery (MIGS). HFDS creates direct access from the anterior chamber to the Schlemm’s canal, thereby avoiding the resistance of the trabecular meshwork. This leads to excellent long-term results and a low complication rate despite the short intervention time.


    «HFDS offers three unique advantages in glaucoma surgery.
    First, in about 70% of cases no postoperative treatment with medication is required. The second and biggest advantage in my opinion is that trabeculotomy and trabeculoplasty can be replaced by HFDS. Third, HFDS and phaco act additively and thus an IOP reduction of up to 13 mmHg can be achieved.»

    Dr. Gonzalo Murillo Azcarraga
    Instituto Privado de Oftalmología La Paz, Bolivia

    «Thanks to the modern HFDS method from Oertli, I am able to work quick and safe with little effort. It is also a good alternative to implants or filter surgery. The result speaks for itself - many patients are well regulated even after months without glaucoma drops.»

    PD Dr. med. Hans-Joachim Hettlich
    Augen Praxisklinik Minden, Germany

    «HFDS convinces me because the procedure is very easy to perform, highly controllable and with few complications. Thanks to HFDS, excellent long-term results are achieved, resulting in fewer follow-up treatments for patients.»

    Dr. med., F.E.B.O. Lutz Blomberg
    Augenzentrum Hildesheim-Alfeld, Germany

    «For me, HFDS is an easy to apply MIGS solution, which convinces not only because of the fast rehabilitation post-op. High frequency diathermy is used to reduce the outflow resistance and shows excellent eye pressure reduction. HFDS can be excellently combined with cataract surgery.»

    Prof. Bojan Pajic
    Eye Clinic Orasis, Reinach, Switzerland


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 HFDS 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

What is HFDS®?

HFDS (High Frequency Deep Sclerotomy) is the implant-free MIGS solution for glaucoma treatment. But what exactly is HFDS? This video explains in which cases the HFDS procedure is used and which instruments are applied.

The HFDS® procedure

The HFDS (High Frequency Deep Sclerotomy) procedure is an implant-free MIGS procedure to lower intraocular pressure by reducing the outflow resistance of the aqueous humour. In this animation, all surgical steps of the HFDS procedure are explained.

See HFDS® in application now


Clinical studies confirm a long-term significant reduction in the IOP with a considerable reduction in the number of antiglaucoma medication (AGM) [1]. Together with the low complication rates, HFDS is a safe and efficient glaucoma procedure [1, 2, 3].

[1] B. Pajic, B. Pajic-Eggspuehler, and I. Haefliger, “New minimally invasive, deep sclerotomy ab-interno surgical procedure for glaucoma, six years of follow-up,” Journal of glaucoma, vol. 20, no. 2, pp. 109–114, 2011, doi: 10.1097/IJG.0b013e3181dddf31.

[2] B. Pajic, Z. Cvejic, K. Mansouri, M. Resan, and R. Allemann, “High-Frequency Deep Sclerotomy, A Minimal Invasive Ab-interno Glaucoma Procedure Combined with Cataract Surgery: Physical Properties and Clinical Outcome,” Applied Sciences, vol. 10, no. 1, p. 218, 2020, doi: 10.3390/app10010218.

[3] Kaweh Mansouri, M.D., M.P.H., A Multicenter Prospective Study of High-Frequency Deep Sclerotomy (HFDS) in Open-Angle Glaucoma: 3-Year Outcomes: Manuskript; UNPUBLISHED DATA.


Recent studies & postoperative treatment

With HFDS, a reduction in intraocular pressure is already noticeable in the first few days after the operation. In the following video you will learn why you do not need pressure-reducing eye drops and how the reduction in intraocular pressure is measured using the latest studies.

What do experts say about HFDS®?

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HFDS in glaucoma surgery

Learn more about about the instruments for glaucoma surgery.

More about HFDS


With the compact, mobile and flexible training tool, we provide a more impactful introduction into HFDS than ever before.

More about the HFDS DryLab KIT

The complete animation of HFDS

Watch the animation for HFDS in full length here.

Watch here

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.

More about Cataract