Effects of Cataract Surgery on Endothelium in Transplanted Corneal Grafts: Comparison of Extracapsular Cataract Extraction and Phacoemulsification for Complicated Cataract after Penetrating Keratoplasty

BACKGROUND: The endothelium should be carefully evaluated when choosing a surgical technique for cataract removal. Therefore, we aimed to study the effects of different cataract surgery techniques on endothelial cell loss in transplanted corneal grafts. METHODS: A total of 54 patients who received complicated cataract surgery in post-penetrating keratoplasty (PKP) eyes at the Shandong Eye Institute between February 2001 and June 2014 were included, and clinical records were reviewed. Baseline demographic details, clinical characteristics, endothelial cell density (ECD), and best-corrected visual acuity (BCVA) were recorded. Wilcoxon rank-sum test and Wilcoxon signed-rank test were used to test the equality of medians. A regression model was constructed to compare the reduced rate of ECD. RESULTS: Of the 54 eyes included in this study, extracapsular cataract extraction (ECCE) was performed in 34 eyes of 33 patients (ECCE group) whereas phacoemulsification was performed in 20 eyes of 20 patients (phacoemulsification group). There was no significant difference in the median age (P = 0.081) or preoperative ECD (P = 0.585) between the two groups. At 6 months after cataract surgery, ECD in ECCE group was significantly higher than that in phacoemulsification group (P = 0.043). In addition, the endothelial cell loss rate in ECCE group was significantly lower than that in phacoemulsification group at 2 months (P = 0.018), 4 months (P < 0.001), and 6 months (P < 0.001) after cataract surgery. Endothelial cell loss rate after cataract surgery increased over the 6-month study duration in both ECCE group (P < 0.001) and phacoemulsification group (P < 0.001), but phacoemulsification resulted in a greater reduction in ECD than that of ECCE in transplanted corneal grafts (P < 0.001). There was no significant difference in postoperative BCVA between the two groups (P = 0.065). CONCLUSION: ECCE is more suitable than phacoemulsification in cataract surgery in complicated cataract after PKP.