Aims: To describe the fitting of patients with high or irregular astigmatism following penetrating keratoplasty with contact lenses and to answer the question whether or not contact lenses with special back surface design can improve visual acuity in complex cases after penetrating keratoplasty. Methods: 28 eyes were included. They were fitted with contact lenses with a special back surface that was designed for optical rehabilitation after penetrating keratoplasty. Four different types of these lenses (tricurve, keratoconus, reverse, oblong) were used selectively depending on abnormal eccentricity determined by videokeratoscope. The patients were followed up for an average period of 15.5 months. Lens tolerance and corrected visual acuity were evaluated and compared with that corrected with spectacles. Results: The visual acuity was significantly improved in nearly all eyes with an average increase of 3.6 lines (maximal nine lines) accompanied by good contact lens tolerance and satisfactory contact lens fit. No noticeable complications were observed. Conclusion: Contact lenses with special back surface design can improve visual results and lens tolerance, and minimise problems in contact lens fitting. This is in favour of contact lenses as an alternative to surgical procedures for correction of high or irregular astigmatism after penetrating keratoplasty. This procedure is recommended especially in cases of patients who decline further operative interventions. P ostoperative astigmatism is the main reason for unsatisfactory visual results after grafting. Various studies have shown that the number of grafts with (3D of astigmatism 2 years after transplantation ranges between 27% and 34%, depending on the indication for corneal grafting.1 2 To achieve visual benefit and binocularity there is a strong necessity for optical or operative correction of the postoperative high astigmatism. A number of surgical and non-surgical approaches have been taken to reduce postoperative irregular astigmatism.Surgical options for dealing with cylindrical error were already developed 40 years ago. Suture adjustment or selective suture removal are the first option to reduce the postoperative astigmatism. [5][6][7][8][9]

We could reach a satisfactory improvement of visual acuity in more than 90 % of the patients fitted for the far and the reading distance. Especially in elderly, vision impaired patients significant improvements in overall quality of life and specific areas of daily living are possible.

Irregular astigmatism and the aberration coefficient are useful parameters in detecting ectatic corneal disease using a computerized videokeratoscope. The calculation of the spherical equivalent (Fourier series harmonic analysis: no decrease of spherical equivalent in PMCD subjects) and of quadrant eccentricities are useful tools in distinguishing PMCD and keratoconus.

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