Changes in Corneal Power After Descemet Stripping Automated Endothelial Keratoplasty.

ABSTRACT

PURPOSE: To examine the optical effects of Descemet stripping automated endothelial keratoplasty (DSAEK) by evaluating changes in anterior and posterior corneal curvatures and aberrations. METHODS: Eighty-three eyes treated using DSAEK combined with cataract surgery (the DSAEK group) and 41 control eyes of healthy patients (the control group) were included. Patients were examined before and 1 year after surgery with autokeratometry and Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany). The preoperative posterior corneal curvature was estimated from the anterior corneal curvature. RESULTS: The mean intended postoperative refraction in the DSAEK group was -0.75 ± 0.62 diopters (D), which was statistically different from the achieved refraction of +0.50 ± 0.93 D at the 1-year follow-up (P < .001). The average biometry prediction error was a hyperopic shift of +1.27 ± 0.80 D. Anterior corneal power was significantly higher before than after DSAEK with a difference of -0.63 ± 0.68 D (P = .03) correlating significantly with the hyperopic change (r(2) = 0.23, P < .01). The posterior corneal power after DSAEK showed a significant steepening of -0.69 ± 0.38 D (P < .01) from the estimated preoperative power and a difference of -0.64 ± 0.38 D (P < .01) from the posterior corneal power in the control group. The change correlated significantly with the hyperopic change (r(2) = 0.10, P < .01). The combined changes in anterior and posterior keratometry increased the correlation coefficient to r(2) = 0.34 (P < .01). Significant differences were observed for total higher-order aberrations root mean square and coma root mean square after DSAEK compared to controls. No significant changes were observed in spherical aberration. CONCLUSIONS: The hyperopic shift in the DSAEK group can be explained by changes in anterior and posterior corneal surfaces. Spherical aberration was not changed by DSAEK, suggesting that aspherical intraocular lenses may be implanted on the same indications as in normal cataract surgery.