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HFDS glaucoma surgery

IOP Reduction.
Zero implants.

With High Frequency Deep Sclerotomy (HFDS), OS 4 Up™ offers an implant-free, ab interno procedure for micro-invasive glaucoma surgery (MIGS) to treat primary open-angle glaucoma.

Cross-sectional illustration of the eye showing an HFDS probe creating controlled openings in the trabecular meshwork with arrows indicating enhanced aqueous humour outflow
Micro-invasive glaucoma treatment

What is HFDS?

ophthalmologist while eye surgery with the instrument hfds glaucoma tip
Cross-sectional medical illustration of the eye showing HFDS creating outflow pockets in the trabecular meshwork with a probe inserted into Schlemm’s canal

High Frequency Deep Sclerotomy (HFDS) is an implant-free micro-invasive glaucoma procedure that aims to lower intraocular pressure by reducing the outflow resistance of aqueous humour.

HFDS glaucoma surgery

Why treating primary open-angle glaucoma with HFDS

Implant-free and micro-invasive:
HFDS aims to improve natural aqueous humour outflow and lower IOP, entirely without the need for permanent implants.

Improved outflow: HFDS provides direct access from the anterior chamber to Schlemm’s canal and further into the sclera, supporting improved aqueous humour outflow and sustained IOP reduction.

Long-term IOP reduction: Clinical studies have confirmed a long-term and significant reduction in IOP over a 4-year period, together with a reduction in anti-glaucoma medications (AGMs) (4).

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Stand-alone or combined surgery: HFDS can be combined with cataract surgery or utilised as a stand-alone application (3).

Cross-sectional medical illustration of the eye showing HFDS creating outflow pockets in the trabecular meshwork with a probe inserted into Schlemm’s canal
Cross-sectional medical illustration of the eye showing HFDS creating outflow pockets in the trabecular meshwork with a probe inserted into Schlemm’s canal
Medical illustration showing improved aqueous outflow through the trabecular meshwork with arrows indicating fluid movement from the anterior chamber into the drainage pathway
diagram of the iop in mmhg from day 1 to 48 months with hfds
Simplified cross-sectional diagram of the eye highlighting the anterior chamber and cataract application field for phaco surgery
Open-angle glaucoma treatment

Lower IOP with High Frequency Deep Sclerotomy

The HFDS glaucoma tip is inserted through a 1.2 mm paracentesis and uses high-frequency diathermy to create six small pockets in the iridocorneal angle. This technique aims to improve natural aqueous humour outflow and lower IOP, entirely without the need for permanent implants.

Illustration explaining HFDS, high frequency deep sclerectomy, in glaucoma treatment showing aqueous humour outflow pathway
Oertli community

How HFDS fits into glaucoma treatment

«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». (D)

Dr. Lutz Blomberg
Eye Centre Hildesheim-Alfeld, Germany

Portrait of ophthalmologist in clinical setting, wearing white coat and glasses, smiling against softly blurred background
Surgical steps of HFDS procedure

HFDS step-by-step

  • Patient head tilted at 35 degrees with arrow indicating positioning angle for HFDS procedure

    1. Tilt patients head and microscope

    Tilt the patient’s head by 35° and tilt the microscope to ensure optimal visibility of the iridocorneal angle.

  • human eye with instument in action

    2. Anaesthesia & moistening of the cornea

    The HFDS procedure can be carried out under local anaesthesia. A viscoelastic substance is applied to the cornea to ensure constant moistening.

  • human eye with hfds incision

    3. Incision

    For nasal access, perform a 1.2 mm temporal or bitemporal incision.

  • human eye before hfds incision

    4. Induction of miosis

    Narrow the pupil using drops or an intracameral injection to protect the lens and improve visualisation of the angle.

  • human eye visualisation with hfds incision

    5. OVD application

    Fill the anterior chamber with a high-viscosity viscoelastic substance (OVD) to maintain space and stabilise the target area.

  • Close-up of a human eye during ophthalmic surgery, showing a surgical instrument inserted through the cornea towards the pupil

    6. Insertion of the HFDS tip

    The HFDS glaucoma tip is inserted through the incision and positioned at the desired point of application.

  • human eye visualisation with hfds positioning

    7. Visualisation of the iridocorneal angle

    Apply viscoelastic substance to the cornea. Place a direct or indirect goniolens. This allows for a clear view of the Schalbe's line and the pigmented trabecular meshwork.

  • graphic of the application with hfds

    8. Positioning of the HFDS tip

    Position the HFDS tip in the iridocorneal angle below Schwalbe's line and above the scleral spur at the level of the pigmented trabecular meshwork.

  • graphic of the procedure with hfds and the foot pedal

    9. HFDS pockets creation

    Press the pedal and simultaneously push the HFDS tip forward to create a 1 mm pocket. Using high-frequency energy, six small pockets are formed.

  • medical products after the op

    10. Postoperative medication

    According to the recommendation of Prof. Bojan Pajic, it is advised to use Tobramycin/Dexamethasone, either as a fixed combination or separately, four times daily for four weeks, supplemented by Pilocarpine 2 % eye drops for two weeks.

Illustration of HFDS glaucoma treatment showing surgical steps and aqueous humour outflow pathways
Oertli community

How HFDS supports drop-free outcomes

«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». (D)

Dr. Hans-Joachim Hettlich
Eye Practice Clinic Minden, Germany

ophthalmologist with a smile
Clinical evidence

HFDS long-term results

In the treatment of primary open-angle glaucoma, Oertli’s HFDS ab interno MIGS technology delivers promising long-term results in reducing IOP. Clinical studies have confirmed a long-term and significant reduction in IOP over a 4-year period, together with a reduction in anti-glaucoma medications (AGMs).

Illustration of HFDS glaucoma treatment showing surgical steps and aqueous humour outflow pathways
Clinical evidence

Significant reduction of IOP and AGM

Graphic showing an average intraocular pressure reduction of 53.4 percent after 1.5 years
Graph showing change in intraocular pressure over nine months with mean IOP decreasing from preoperative baseline and stabilising during follow up
Bar chart showing reduction in the mean number of anti glaucoma medications over time from preoperative baseline to long term follow up
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HFDS key visual with human eye visualisation
FAQ

In a nutshell about HFDS in glaucoma surgery

In focus

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