RESUMO
PURPOSE: To investigate changes of corneal power after descemet stripping automated endothelial keratoplasty (DSAEK). METHODS: Anterior, posterior, and true-net (anterior + posterior) power of post-DSAEK and contralateral transparent corneas were measured, using the Pentacam rotating Scheimpflug camera (Oculus Wetzlar, Germany), 6 months after surgery in 23 consecutive patients who had undergone unilateral DSAEK at the same medical center. Moreover, in each cornea, Pentacam pachimetry was measured at the vertex and at 3 mm from the vertex, to calculate corneal thickness increase (CTI). RESULTS: In post-DSAEK corneas, the anterior power on average decreased by -0.24 ± 0.61 diopters (D), the negative posterior power increased by -0.96 ± 0.42 D, and the true-net power decreased by -1.19 ± 0.74 D (range: +0.17 to -2.23 D). Differences vs. contralateral transparent corneas did not reach statistical significance for anterior (p = 0.09) but were significant (p < 0.001) for posterior and true-net corneal power. CTI at 3 mm from the vertex was statistically larger (p < 0.0001) in post-DSAEK corneas (mean values 0.27 ± 0.07 vs. 0.12 ± 0.05); CTI values showed a statistically significant (p < 0.05) correlation with negative posterior corneal power values in post-DSAEK (r = -0.55) and in contralateral corneas (r = -0.67). CONCLUSIONS: In comparison with contralateral corneas, post-DSAEK corneas show a moderate reduction of the true-net corneal power measured by Pentacam. Knowledge of true-net corneal power changes might be useful in adjusting K values and calculating intraocular lens power, in eyes scheduled for DSAEK combined with intraocular lens implantation/exchange.
