1Hugger P., 1,2Jonas J. B.

1Department of Ophthalmology, Faculty of Clinical Medicine Mannheim, Ruprecht-Karls- University Heidelberg; 2Department of Ophthalmology, Friedrich-Alexander-University rlangen-Nürnberg

Purpose: Penetrating keratoplasty has become the treatment of first choice for several corneal diseases including advanced keratokonus, Fuchs endothelial dystrophy, and herpetic corneal scars. To preoperatively determine the postoperative refractive error, it is useful to know how the keratometric power changes due to surgery. It was the purpose of the present study to study how the spherical equivalent of the corneal refractive power changes by keratoplasty and which factors influence the outcome.
Patients and Methods: The retrospective clinical interventionel single-surgeon case series study included 245 patients undergoing homologous central penetrating keratoplasty for keratoconus (n=77), herpetic corneal scars (n=29), non-herpetic corneal scars (n=46), Fuchs´ endothelial dystrophy (n=24), and pseudophakic/aphakic bullous keratopathy (n=69). Mean follow-up time was 30.4 ± 18.7 months. All patients were operated on by the same surgeon.
Results: Taking the whole study group, the spherical equivalent of the corneal refractive power changed significantly (P=0.02) from 46.42 ± 6.34 D preoperatively to 44.13 ± 5.20 D postoperatively. The changes were significantly (P<0.05) most marked for the keratokonus group, in which the change was significantly and positively correlated with the preoperative keratometric readings. In the study groups except the keratokonus group, the preoperative readings and the postoperative readings did not vary significantly (43.33 ± 2.80 D versus 43.74 ± 2.96 D; P>0.10). The surgically induced change in the spherical equivalent of the corneal refraction did not vary significantly between the study groups except the keratokonus group. The diameter of the graft and its oversize did not significantly (P>0,10) influence the surgerically induced change.
Conclusions: In patients with keratokonus, penetrating keratoplasty leads to a marked reduction in the corneal refractive power. These changes are positvely correlated with the preoperative corneal refractive power. For the other reasons of penetrating keratoplasty examined in the present study, keratoplasty did not markedly change the spherical equivalent of the corneal refractive power. These results may have importance for the preoperative biometry.

Copyright © Deutsche Ophthalmologische Gesellschaft, 2001. All rights reserved.

Last updated: 

Webdesign: SPALLEK.COM