The predictability of graft thickness for Descemet's stripping automated endothelial keratoplasty using a mechanical microkeratome system.

Descemet's stripping automated endothelial keratoplasty (DSAEK) is used for treating corneal endothelial dysfunction, and the postoperative visual acuity outcome depends on the thickness of the graft. We created a simple nomogram using factors affecting the cutting thickness during graft preparation via a mechanical microkeratome system for DSAEK. This retrospective study was conducted from May 2018 through October 2022 and included donor eyes cut by automatic methods. We measured the graft thickness, cutting accuracy, and assessed ten variables with donor/cornea-related factors potentially affecting the cutting thickness. Subsequently, we created a simple nomogram. We analyzed 81 donor tissues, and the donor median age was 76 years. The mean central graft thickness was 122.2 µm, with 62% of the grafts that could be cut within the target central graft thickness range. Comparatively, donor corneas from those with cardiac diseases were cut deeper (P = 0.007). The developed nomogram provided a 83% probability of estimating the post-cutting graft thickness within 25 µm. Our nomogram, which considers cause of death, enables reproducible production of graft of a desired thickness. A detailed analysis of donor tissues, including the cause of donor death and the characteristics from pressurization to cutting, will enable more precise DSAEK graft preparation.

Donor-Related Risk Factors for Graft Decompensation Following Descemet's Stripping Automated Endothelial Keratoplasty.

AIMS: To identify donor-related risk factors associated with graft endothelial failure and postoperative endothelial cell density (ECD) reduction after Descemet's stripping automated endothelial keratoplasty (DSAEK). METHODS: This was a single-center retrospective study conducted from July 2006-December 2016. We included 584 consecutive eyes (482 patients) that underwent DSAEK for the treatment of laser iridotomy-related bullous keratopathy (192 eyes), pseudophakic bullous keratopathy (137 eyes), regraft (96 eyes), Fuchs' endothelial corneal dystrophy (FECD; 59 eyes) and others (100 eyes). Twenty-three donor- and recipient-related risk factors potentially associated with graft failure and ECD reduction were assessed using Cox hazard models and linear mixed effect models. RESULTS: The median age of the patients was 73.5 years (male; 35.6%). After DSAEK, ECD decreased from 2,674 cells/mm2 (95% confidence interval [CI]; 2,646-2,701) to 1,132 (1,076-1,190) at 12 months and 904 (845-963) at 24 months (P < 0.001). Fifty-five eyes (9.4%) had graft endothelial failure without rejection. This failure was associated with donor pseudophakic lens status (hazard ratio [HR]; 2.67, CI; 1.50-4.76, P = 0.001) and preoperative endothelial folds (HR; 2.82, CI; 1.20-6.62, P = 0.02). The incidence of graft endothelial failure in non-FECD patients was significantly higher among those receiving donor grafts with a pseudophakic lens status and preoperative presence of endothelial folds (P < 0.001). Postoperative ECD loss was significantly greater in eyes with these risk factors compared to those without (P = 0.007). CONCLUSIONS: Pseudophakic status and/or presence of preoperative endothelial folds are the significant donor risk factors for endothelial failure in non-FECD patients.

Trends in surgical procedures and indications for corneal transplantation over 27 years in a tertiary hospital in Japan.

PURPOSE: To characterize trends in procedures, and indications for corneal transplantation over 27 years in a single referral center in Japan. STUDY DESIGN: Retrospective study. METHODS: Data from a consecutive series of corneal transplant surgery cases performed from 1991 to 2017at Ichikawa General Hospital were collected. The surgical procedures, indications, and causes of corneal endothelial dysfunction were evaluated. RESULTS: Among 6,025 transplantations, a total of 3,991 cases underwent penetrating keratoplasty (PKP), 1009 underwent (deep) anterior lamellar keratoplasty, 746 underwent endothelial keratoplasty, and 309 underwent epithelial transplantation. Over that period the frequency of PKP decreased, whereas the frequency of lamellar keratoplasty increased. The four major surgical indications were bullous keratoplasty (BK 30.0%), regraft (24.2%), post-keratitis scars (17.1%), and keratoconus (11.4%). After dividing the study period into four time periods, we found that BK and regraft increased (from 20.3% to 34.5% and 18.2% to 31.1%, respectively), whereas post-keratitis scars and keratoconus decreased (from 26.0% to 9.5% and 14.1% to 7.2%, respectively) between the first and last period. Pseudophakic or aphakic BK were the major causes of corneal endothelial dysfunction until 2010. Cases of laser-iridotomy-induced BK peaked in 35 eyes (34.3% of BK) in 2000 and declined after 2013. Cases of Fuchs endothelial corneal dystrophy increased from 0 in 1991, to 15 eyes (18.5% of BK) in 2017. CONCLUSION: Lamellar keratoplasty has replaced PKP in our hospital. BK and regraft have increased, whereas post-keratitis scars and keratoconus have decreased. Laser-iridotomy-induced BK has decreased during the past decade, whereas Fuchs endothelial corneal dystrophy has increased.

Comparison of Artificial Anterior Chamber Internal Pressures and Cutting Systems for Descemet's Stripping Automated Endothelial Keratoplasty.

PURPOSE: To optimize methods of preparing donor cornea tissue for Descemet's stripping automated endothelial keratoplasty (DSAEK), we compared five experimental conditions with different internal pressures and cutting systems. METHODS: The artificial anterior chamber internal pressure (IP) was set at 100 or 200 mm Hg. The microkeratome cut was performed with or without an artificial chamber pressurizer (ACP), using a CBm turbine (CBm) or one use-plus automated (OUP-A). Thirty human research corneas were divided into five groups, and compared after the cut with donor tissue quality parameters, including cutting depth, graft uniformity, cell evaluation, and smoothness of the stromal surface. RESULTS: The smallest variation in mean cut depth was observed in the condition, which had IP of 200 mm Hg used ACP and OUP-A. In experimental groups cut using CBm, significantly more consistent thicknesses were made at an IP of 200 than 100 mm Hg. There were no statistically significant differences among the groups in either endothelial cell density or cell viable assay results after cuts. Using an IP of 200 mm Hg with ACP and CBm produced the roughest stromal surface, and the roughness grading scores showed a positive correlation with the percentage of cut depth. CONCLUSIONS: An IP of 200 mm Hg was the best setting for DSAEK grafts with high predictability of cut depth and uniformity of graft thickness without endothelial cell damage. TRANSLATIONAL RELEVANCE: For successful DSAEK, it is recommended that a set internal pressure of 200 mm Hg be used during microkeratome cutting for donor tissue preparation.

[Two cases of intraoperative cerebral hemorrhage caused by undiagnosed metastatic brain tumors].

The authors report two cases of intraoperative cerebral hemorrhage caused by metastatic brain tumors. Delayed recovery from general anesthesia and neurological deficit were found in these patients. Brain CT in case 1 showed bilateral subdural hemorrhage and parenchymal massive hemorrhage in case 2. It is thought that the causes of hemorrhage are due to the changes in morphology of vessels, deterioration in cerebral circulatory regulated system, and increased intracranial pressure caused by tumors. Since the incidence of metastatic brain tumor has increased with prolonged survival time induced by progress in cancer therapy, preoperative brain examination and careful attention to vital signs during anesthesia are needed.