Retinal surgery > Treatment

Prof. Koss is the winner of the most decorated award of the German ophthalmological society (Leonhard Klein Prize) for his surgical innovations in the field of vitrectomy.


A number of diseases can only be cured by surgery.

In almost all cases, it is necessary to remove the vitreous in order to be able to carry out surgical measures directly or under the retina. This complex of operations is described by the term “vitrectomy”, which literally means “cutting out the vitreous body”. However, this process alone is only a partial aspect of often complicated interventions.

In the case of eyes that still contain lenses, these procedures are often combined with the removal of the eye lens and simultaneous replacement with a plastic lens.

Surgical access to the vitreous cavity takes place in the area of ​​the so-called pars plana of the ciliary body. The more detailed description of this surgical procedure is referred to as pars-plana vitrectomy (or PPV for short). The accesses are approximately 3.5 to 4 mm from the cornea.

Vitrectomy is performed through minimally invasive approaches to the eye. Depending on the size of the access, we speak of a 20-gauge, 23-gauge, 25-gauge, 27-gauge vitrectomy. The access cuts are only 0.9mm, 0.6mm, 0.5mm or 0.4mm in size.

The surgeons at the Nymphenburger Höfe Eye Center have immense experience in the treatment of all retinal diseases. During surgical procedures, they almost only perform vitrectomies with a 23-gauge or 25-gauge system (0.6 mm or 0.4 mm). The wound trauma is minimal, even if the operation is combined with a lens removal. Only in rare cases must stitches be made. The procedures are designed in such a way that the access routes close by themselves.

Vitrectomy is considered in the following cases:

  • With retinal detachments.
  • With vitreous bleeding for various reasons.
  • In advanced diabetes-induced proliferative retinopathy. The excessive formation of blood vessels in the vitreous and in the retina can lead to bleeding and retinal detachment in this disease.
  • For macular diseases such as a hole in the macula (macular foramen) or for adhesions on the macula (for so-called epiretinal gliosis = macular pucker) or for complicated cases of AMD.
  • With vitreous opacities, for example with chronic or acute inflammation or with massively disruptive other forms of opacification.

The operation is performed under local anesthesia and general sedation. General anesthesia is rarely necessary. The combination of sedation and local anesthesia means that the operation itself is not perceived as bad at all and the patients are happy that they have been spared general anesthesia.

The surgeon uses a microscope and additional special lens systems for the procedure to perform the microsurgical manipulations on the retina.

The following steps are carried out:

  • Our surgeons use the minimally invasive vitrectomy technique so that the eye is strained as little as possible. The surgical instruments are only 23 g (0.6 mm) or 25 g (0.4 mm) in size. This enables tiny openings that heal without stitches.
  • The gel-like substance of the vitreous is carefully removed with a special instrument, the vitrector. Now the necessary interventions on the retina can be carried out, such as the removal of adhesions on the retina, laser treatments, removal of fluid under the retina and others.
  • To stabilize the retina, function-specific fluids are entered if necessary to replace the removed vitreous.
    Temporary stabilization can be achieved by gases that disappear from the eye on their own within a period of a few days or up to 3-4 weeks.
  • In certain situations, long-term stabilization of the retina is necessary. In these cases, only silicone oil can be used as it has been the only substance for long-term vitreous replacement for many years.