CISIS stands for Corneal IntraStromal Improvement Surgery, also referred to as MyoRing Keratoplasty. It is the the currently most effective treatment of keratoconus. The treatment permits both, improvement of vision and stop of the progression of the disease.
CISIS is therefore the first available treatment which is able to achieve something like "healing" of keratoconus.
The procedure is minimally-invasive and performed under topical anesthesia (eye drops) only. It lasts in total some 10 - 15 minutes and is free of pain. The wound is self-sealing and heals within a few hours. No suture and no patching of the eye is required. The MyoRing can be removed at any time (reversibility) - the eye is then as before the surgery. The MyoRing cannot move by itself inside the cornea and even eye-rubbing cannot displace its position.
CISIS is a 2 step procedure:
1st step: Preparation of the cornea for MyoRing implantation by creating a virtual slit in the cornea 300 microns underneath the corneal surface either by means of a Femtosecondlaser or by means of the PocketMaker Ultrakeratome, a devices of unrivaled precision and safety designed especially for MyoRing keratoplasty. Our centre has both devices available. In most of the cases the PocketMaker is the best choice because it is extremely precise at 300 microns depth and the preparation of the tissue is perfectly smooth. The Femtosecondlaser in comparison rather disrupts the tissue instead of smoothly preparing it and will therefore be used as an alternative if the PocketMaker is not applyable for any reason. The final decision, however, which device will be used in a particular case is made after the preoperative examination. This step, the preparation of the cornea last some 20 - 30 seconds.
2nd step: Inserting the MyoRing into the cornea via a narrow entrance. At the end of the procedure the MyoRing has to be aligned with the optical axis. The tiny lamellar would is self-sealing and no suture is required.