Endothelial image quality after descemet stripping with endothelial keratoplasty: A comparison of three microscopy techniques

Purpose: To determine corneal endothelial image quality after descemet stripping with endothelial keratoplasty (DSEK) as recorded by three different microscopy techniques: noncontact specular microscopy, noncontact confocal microscopy, and contact confocal microscopy. Methods: The corneal endothelium of 52 eyes after DSEK and 20 normal eyes was photographed by the three microscopy techniques during a single encounter. Image quality was graded by two masked observers according to the proportion of countable contiguous cells visible in the image; disagreements in grading were adjudicated by a third observer. Endothelial cell density was compared among the three techniques. Results: After DSEK, image quality was better with contact confocal microscopy than with noncontact confocal microscopy (P = 0.01) and better with noncontact confocal microscopy than with noncontact specular microscopy (P < 0.001). With noncontact specular microscopy, 42% of images after DSEK were uncountable. In normal corneas, all images were countable, and although image quality was better with contact confocal microscopy than with noncontact confocal (P = 0.03) and noncontact specular (P < 0.001) microscopy, the difference was not clinically important. For countable images, the mean differences in endothelial cell density between microscopy methods were close to zero after DSEK and in normal corneas. Conclusions: Confocal optics enable better image quality of the corneal endothelium in corneas with high backscatter, such as those after DSEK. When images were countable, there was a good agreement for endothelial cell density measured by the three microscopy techniques.