Effect of Simultaneous Endothelial Keratoplasty and Cataract Surgery: A Secondary Analysis of the Descemet Endothelial Thickness Comparison Trial

Purpose:Combining cataract surgery with endothelial keratoplasty (triple EK) is a common practice and may be safer because it commits the patient to only one surgery. This study aimed to determine whether outcomes of pseudophakic endothelial keratoplasty and triple EK have similar outcomes.Methods:This was a non-prespecified secondary analysis of a multicenter, double-masked, randomized, controlled clinical trial. Enrollment centers included the Casey Eye Institute at Oregon Health and Sciences University and the Byers Eye Institute at Stanford University. Patients with damaged or diseased endothelium and were considered good candidates for either Descemet membrane endothelial keratoplasty or ultrathin Descemet stripping automated endothelial keratoplasty were randomized to one of the two surgeries 1-2 days prior to surgery. If the patient had a cataract, they underwent simultaneous cataract surgery. The primary outcome was visual acuity at 6 months. Visual acuity at 3, 12, and 24 months, 3, 6, 12, and 24 month endothelial cell density and intraoperative and postoperative complications were also recorded.Results:Those who had pseudophakic EK generally were older, more likely to be male, and more likely to have worse baseline vision with higher corneal densitometry values. After controlling for baseline visual acuity and type of keratoplasty, those that underwent Triple-EK had 0.09 better LogMAR lines better visual acuity at 6 (95% CI -0.17 to -0.10; P = 0.02) and 12 months (95% CI -0.21 to -0.07; P = 0.03). Although those receiving Triple- EK had nearly one-half LogMAR line better visual acuity at 24 months, it was no longer statistically significant (95% CI -0.20 to -0.05; P = 0.36). There was no statistically significant difference in ECD between groups at any timepoint. Those undergoing triple EK were more likely to have at least one adverse event (P = 0.02).Conclusions:Earlier intervention with Triple-EK may improve visual acuity outcomes after endothelial keratoplasty compared with staged procedures, but may also increase the risks of adverse events including the need for re-bubble.