Keratoconus I + II
Details on Circular Keratotomy
Circular Keratotomy (CKT) is a trephine cut into he patient's own cornea with the Guided Trephine System (GTS). Prerequisite for the use of this technique is a thickness of >450µm at the site of the incision of a 7mm trephine around the optical axis. With the instrument the cornea is fixated with a special suction ring and the inner surface is rounded within the trephine. The cut is then performed to 90% of the depth of the cornea as measured with Orbscan.(Fig.1) Aim of the procedure is to create a circular scar that creates millions of connecting tissue fibres. We have noted in 91% a complete stop of any steepening of the corneal radii (K-Readings), which would occur typically with the progression of Keratoconus. In 70% visual acuity improved. To date we have 366 cases 71 of which are consecutive cases over a period of seven years. (Fig.2) Also topographies - surface images of the cornea 6 years apart - show stability (Fig.3)In many cases not only stability, but improvement of the central area can be observed. (Fig. 4). The procedures described are procedures for Stage I or II. If the cone is progressed further, the scar generated is not strong enough to stop the progression of the disease.