Long-term results of penetrating keratoplasty with different trephine systems -- a clinical investigation from the university eye hospital of halle/saale and the eye clinic of the helios hospital aue

The results of penetrating keratoplasty in two centres for cornea transplantation were investigated with regard to the following parameters: the trephine system used, the origin of the donor cornea, the influence on the postoperative astigmatism and other aspects. The retrospective clinical investigation reports about the results of 186 patients with penetrating keratoplasty from the University Eye Hospital of Halle and 204 patients from the Eye Clinic of the Helios hospital Aue. Three trephine systems have been used: the Hessburg-Barron trephine, the guided trephine system (GTS) and the Asmotom device. There were no significant differences between them concerning visual acuity after 12 months postoperatively. The results were highly significantly better (p = 0.003 Halle; p = 0.001 Aue) when using larger diameters of the trephine (7.5 mm and 8.0 mm). The origin of the donor cornea ("fresh" cornea from a deceased subject or organ cultivated cornea from a cornea bank) had no influence on visual outcome after twelve months (p > 0.8). There were less wound dehiscences using the double running suture in comparison with other techniques (p = 0.05). The removal of suturing material was not effective in reducing postoperative astigmatism (p > 0.11). There was no increase in astigmatism when leaving the sutures in situ (p > 0.25). Generally, each of the three trephine systems can be recommended for clinical use. The trephination should be done with trephine diameters of 7.5 mm or 8.0 mm. A timely operation guarantees better visual acuity at one year postoperatively.