Treffsicherheit der Kunstlinsenberechnung bei Katarakt-Operation nach perforierender Keratoplastik – retrospektive Studie an 72 Augen

Abstract

In concomitant cataract surgery and penetrating keratoplasty (PKP), the sequential procedure is supposed to have a higher accuracy in calculation of the intraocular lens (IOL) power compared to the triple procedure. The purpose of this study was to evaluate the refractive results of cataract surgery in patients after PKP. Our retrospective study included 72 operations on 65 patients. In 35 eyes (group 1, G1), all corneal sutures had been removed before cataract surgery (median time interval after PKP 3.1 years), while in 37 eyes (group2, G2) corneal sutures were in place but removed intra- or postoperatively (median time interval after PKP 1.5 years). Mean age of the patients (65/67 years), mean target refraction (-1.8diopters, D), and mean follow-up interval (2.9/3.4 years) were comparable in G1/G2. Pre- and postoperatively refraction, keratometry, and best corrected visual acuity were recorded. Main outcome measures included the deviation of the spherical equivalent of the real refraction from the target refraction after cataract surgery. In G1/G2 median visual acuity increased from preoperatively 0.2/0.15 to 0.6/0.5 after a follow-up period of 3 years on average. Mean deviation from target refraction was -0.3±2.2 (-4.95 to+3.15) D in G1 and -0.4±3.0 (-7.3 to+7.25) D in G2. After cataract surgery, the steepening of the cornea on average was significantly less in G1 (0.5±1.6 D) than it was in G2 (3.3±2.1D; p=0.003). Although the mean deviation from target refraction is minimal after cataract surgery following PKP, our results indicate a high level of variability. If corneal sutures have been completely removed before biometry, the accuracy of the IOL power calculation seems to be better.