Characteristics of preoperative and postoperative astigmatism in patients having Descemet membrane endothelial keratoplasty

Abstract

To evaluate the characteristics of preoperative and postoperative astigmatism in patients having Descemet membrane endothelial keratoplasty (DMEK). Department of Ophthalmology, Goethe University, Frankfurt, Germany. Retrospective case series. Measurements were obtained using a Scheimpflug camera (Pentacam AXL) preoperatively and 3months and 12months postoperatively. Values of front and back astigmatism and total astigmatism in the central 4.0mm diameter zone (TCA4) were analyzed. Fifty-three eyes of 45 patients were included. The prevalence of TCA4 above 1.0 diopter (D) was considerably higher (79%) and with-the-rule astigmatism was less frequent in this cohort of European patients with Fuchs endothelial dystrophy (mean age 65years) than that reported in a meta-analysis of healthy European eyes. The TCA4 values correlated with anterior astigmatism preoperatively and postoperatively (P<.001) and with posterior astigmatism at the 1-year follow-up (P<.01). Although, no correlation was found between the preoperative and 1-year results for anterior astigmatism (P=.12), posterior astigmatism (P=.35), or total corneal astigmatism (P=.47), the difference in vector analysis between the two measurements was only 0.01 at 109 degrees, 0.03 at 98 degrees, and 0.02 at 157 degrees, respectively. However, the greater the difference between the preoperative TCA3 and preoperative TCA5 values, the greater the decrease in corneal astigmatism (P<.001). The percentage of eyes with corneal astigmatism above 1.0 D was higher preoperatively and postoperatively in patients with Fuchs endothelial dystrophy than in a healthy population. Predicting postoperative astigmatism based on preoperative results is not possible; however, in eyes with a high difference between TCA3 and TCA5, a reduction in corneal astigmatism after DMEK is likely.