Endothelial keratoplasty versus repeat penetrating keratoplasty after failed penetrating keratoplasty: A systematic review and meta-analysis.

OBJECTIVE: This study sought to compare graft survival, graft rejection and the visual acuity outcome of endothelial keratoplasty (EK) with repeat penetrating keratoplasty (PK) after failed PK. METHODS: A systematic literature search with subsequent screening of the identified articles was conducted to obtain potentially eligible randomized clinical trials (RCTs) and comparative cohort studies. To assess the methodological quality of the included studies, the Jadad Scale or Newcastle-Ottawa Scale (NOS) was used based on the study design. To calculate the pooled odds ratios (ORs) for graft survival, graft rejection and the visual acuity outcome with 95% confidential intervals (CIs), a fixed- or random-effects model was applied based on the heterogeneity across studies. RESULTS: Four comparative cohort studies (n = 649 eyes) comparing the outcome of EK with repeat PK after failed PK were included in this review. These studies were considered high quality, with NOS scores ranging from 6 to 9. The EK group showed a significantly lower risk of graft rejection than the repeat PK group [0.43 (95% CI: 0.23-0.80, P = 0.007)]. In addition, no significant differences were observed in a comparison of graft survival and visual acuity (P values ranged from 0.81 to 0.97 using the Der-Simonian and Laird random-effects model). CONCLUSIONS: As an alternative to repeat PK, EK after failed PK allows for potential reduction of the risk of graft rejection; however, it does not appear to confer a significant advantage in graft survival or visual acuity.

Clinical results of non-Descemet stripping endothelial keratoplasty.

AIM: To investigate the impact of non-Descemet stripping endothelial keratoplasty (non-DSEK) on graft rejection rate, and its overall procedural effectiveness in patients. METHODS: Non-DSEK was performed on 65 eyes of 64 patients, and the procedural outcomes, including rejection episodes, failure and dislocation of the grafts, best corrected visual acuity (BCVA), endothelial cell density (ECD), and other complications, were analyzed retrospectively. RESULTS: Of the 65 eyes, 63 recovered from bullous keratopathy with a clear cornea. The mean follow-up time was 26.4mo (range, 6-84mo). The mean BCVA improved from 1.70 logMAR preoperatively to 0.54 logMAR at 3mo, 0.46 logMAR at 6mo, and 0.37 logMAR at 1y after surgery. The postoperative donor ECD of the 25 patients who successfully underwent specular microscopic examination was 1918±534 cells/mm2 (range, 637 to 3056 cells/mm2), and the mean endothelial cell loss was 41.9% at 24mo postoperatively. One eye developed secondary glaucoma and required regrafting via penetrating keratoplasty (PKP). Another eye had postoperative graft failure due to rejection at 26mo. Postoperative graft dislocation occurred in eight eyes. All of the eight dislocated grafts were reattached using air reinjection. CONCLUSION: Immunological graft rejection of the donor graft rarely occurs in non-DSEK. Therefore, non-DSEK is a safe, concise, and effective alternative to restore corneal decompensation when the Descemet membrane is disease-free.