Background: The results of penetrating keratoplasty in two centres for cornea transplantation were investigated with regard to the following parameters: the t rephine system used, the origin of the donor cornea, the i...Background: The results of penetrating keratoplasty in two centres for cornea transplantation were investigated with regard to the following parameters: the t rephine system used, the origin of the donor cornea, the influence on the postop erative astigmatism and other aspects. Patients and Methods: The retrospective c linical investigation reports about the results of 186 patients with penetrating keratoplasty from the University Eye Hospital of Halle and 204 patients from th e Eye Clinic of the Helios hospital Aue. Results: Three trephine systems have be en used: the Hessburg-Barron trephine, the guided trephine system (GTS) and the Asmotom device. There were no significant differences between them concerning v isual acuity after 12 months postoperatively. The results were highly significan tly better (P=0.003 Halle; P=0.001 Aue) when using larger diameters of the treph ine (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 dehiscen ces using the double running suture in comparison with other techniques (P=0.05) . The removal of suturing material was not effective in reducing postoperative a stigmatism (P > 0.11). There was no increase in astigmatism when leaving the sut ures in situ (P > 0.25). Conclusions: Generally, each of the three trephine syst ems can be recommended for clinical use. The trephination should be done with tr ephine diameters of 7.5 mm or 8.0 mm. A timely operation guarantees better visua l acuity at one year postoperatively.展开更多
Background:Wavefront-guided LASIK-treatments should reduce high-order aberrations(HOA).However,both the microkeratome cut as well as the ablation itself induce HOA.The purpose of this study was to investigate the amou...Background:Wavefront-guided LASIK-treatments should reduce high-order aberrations(HOA).However,both the microkeratome cut as well as the ablation itself induce HOA.The purpose of this study was to investigate the amount of corrected preoperative measured HOA and induction of new HOA.Methods:In this retrospective study 67 eyes of 45 myopic patients(-2 to-8.1 D SE;spherical equivalent)were treated by standard and wavefront-guided LASIK(Keracor 217z).Pre-and postoperative measurements of total aberrations and contrast sensitivity were performed.The follow-up time was 5.7± 0.9 months.Results:Patients with preoperative increased aberrations of 3rd and 4th order and myopia up to 5D showed a slightly reduction of wavefront deformation.Cases of higher myopic corrections and lower preoperative spherical aberrations developed an increase of spherical aberrations after LASIK.The changes of other HOA showed no correlation with the amount of corrected myopia.Up to-5 D patients showed the trend to better postoperative contrast sensitivity under 3 and 85 cd/m2 after wavefront-guided LASIK than after standard LASIK.A significant advantage of wavefront-guided LASIK can be detected under a spatial frequency of 3 CPD(cycles per degree)and 85 cd/m2.No advantages of any treatment procedure were shown after higher myopic corrections.Conclusion:If preoperative aberrations of 3rd and 4th order were increased and the myopia is< 5D(SE)wavefront-guided LASIK can reduce total ocular HOA.Aberrometric findings after wavefront-guided LASIK in patients with lower preoperative HOA and myopia > 5 D(SE)are comparable with the results after standard treatment.展开更多
文摘Background: The results of penetrating keratoplasty in two centres for cornea transplantation were investigated with regard to the following parameters: the t rephine system used, the origin of the donor cornea, the influence on the postop erative astigmatism and other aspects. Patients and Methods: The retrospective c linical investigation reports about the results of 186 patients with penetrating keratoplasty from the University Eye Hospital of Halle and 204 patients from th e Eye Clinic of the Helios hospital Aue. Results: Three trephine systems have be en used: the Hessburg-Barron trephine, the guided trephine system (GTS) and the Asmotom device. There were no significant differences between them concerning v isual acuity after 12 months postoperatively. The results were highly significan tly better (P=0.003 Halle; P=0.001 Aue) when using larger diameters of the treph ine (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 dehiscen ces using the double running suture in comparison with other techniques (P=0.05) . The removal of suturing material was not effective in reducing postoperative a stigmatism (P > 0.11). There was no increase in astigmatism when leaving the sut ures in situ (P > 0.25). Conclusions: Generally, each of the three trephine syst ems can be recommended for clinical use. The trephination should be done with tr ephine diameters of 7.5 mm or 8.0 mm. A timely operation guarantees better visua l acuity at one year postoperatively.
文摘Background:Wavefront-guided LASIK-treatments should reduce high-order aberrations(HOA).However,both the microkeratome cut as well as the ablation itself induce HOA.The purpose of this study was to investigate the amount of corrected preoperative measured HOA and induction of new HOA.Methods:In this retrospective study 67 eyes of 45 myopic patients(-2 to-8.1 D SE;spherical equivalent)were treated by standard and wavefront-guided LASIK(Keracor 217z).Pre-and postoperative measurements of total aberrations and contrast sensitivity were performed.The follow-up time was 5.7± 0.9 months.Results:Patients with preoperative increased aberrations of 3rd and 4th order and myopia up to 5D showed a slightly reduction of wavefront deformation.Cases of higher myopic corrections and lower preoperative spherical aberrations developed an increase of spherical aberrations after LASIK.The changes of other HOA showed no correlation with the amount of corrected myopia.Up to-5 D patients showed the trend to better postoperative contrast sensitivity under 3 and 85 cd/m2 after wavefront-guided LASIK than after standard LASIK.A significant advantage of wavefront-guided LASIK can be detected under a spatial frequency of 3 CPD(cycles per degree)and 85 cd/m2.No advantages of any treatment procedure were shown after higher myopic corrections.Conclusion:If preoperative aberrations of 3rd and 4th order were increased and the myopia is< 5D(SE)wavefront-guided LASIK can reduce total ocular HOA.Aberrometric findings after wavefront-guided LASIK in patients with lower preoperative HOA and myopia > 5 D(SE)are comparable with the results after standard treatment.
