The first in Tuebingen developed Placido-Topometer was the C-Scan. It was commercialized by TechnoMed, Germany. After the company was shut down a newly developed "Tübinger Placido Topometer" named OphthaSTAR has been introduced and produced in cooperation with a new industrial partner (Hummel AG, Germany).

The main feature of the new Topometer is the integration of the individual calculation of intra ocular lenses based on Real Ray-Tracing (RRT). Therefore it has to be proven that the technology is capable to be as good as the common calculations. This was shown in several studies. For the Real Ray-Tracing based calculation of Intra ocular lenses it is necessary to get access of information from the lens companies which are normally top secret. To include those data in the software special studies has to be performed to show that the new technology has advantage compared to the actual used formulas. This was done in several studies.

During the development of the new combination system (Placido-Topometer an optical biometer) several setup has been built and tested. The results of those attempts have been presented.

Actually, a combined system of Placido-Topometer and optical length measurement by interferometry will be presented. This device allows the calculation of any kind of Intra Ocular Lenses by just pushing one button. The advantage is the calculation for every human eye, even if the surface is irregular. This allows IOL calculation for eyes after refractive surgery, for extreme eye lengths, for eyes with high corneal astigmatism and all other eyes after corneal treatments.