Minimizing Endothelial Cell Loss Caused by Orientation Stamps on Preloaded Descemet Membrane Endothelial Keratoplasty Grafts.

PURPOSE: To quantify endothelial cell loss (ECL) caused by orientation stamps on prestripped and preloaded Descemet membrane endothelial keratoplasty (DMEK) grafts, and to examine a method for reducing ECL using a smaller stamp. METHODS: Ten prestripped and 10 preloaded DMEK grafts were prepared with S-stamps. Ten additional preloaded DMEK grafts were prepared with both an S-stamp and a smaller F-stamp in different paracentral areas of the graft. The footprint of each stamp was measured using ink on cardstock. DMEK grafts were stored in viewing chambers filled with 20 mL of Optisol-GS for 3 days at 4°C. ECL was quantified using Calcein-AM staining and FIJI Weka Segmentation. RESULTS: S-stamps on prestripped DMEK grafts contributed an average ECL of 1.1% ± 0.5% (range: 0.6%-2.2%) toward total graft damage, whereas S-stamps on preloaded DMEK grafts contributed approximately twice that amount (average ECL: 2.0% ± 0.7%, range: 1.3%-3.1%, P = 0.004). Overall ECL for prestripped grafts (average: 7.1% ± 3.3%, range: 3.3%-13.7%) and preloaded grafts (average: 11.3% ± 4.2%, range: 6.9%-19.4%) was similar to previous reports. The footprint of the S-stamp was approximately 45% larger than that of the F-stamp. In 10 preloaded grafts marked with both stamps, the S-stamp caused an average ECL of 1.9% ± 0.6% (range: 1.2%-3.2%), whereas the smaller F-stamp caused an average ECL of 1.0% ± 0.2% (range: 0.8%-1.4%, P = 0.0002). CONCLUSIONS: Loss of endothelial cells associated with graft-stamping was greater in preloaded tissue than in prestripped tissue and was less with a smaller F-stamp than with a larger S-stamp. Using a smaller stamp could help minimize ECL in prestripped and preloaded DMEK grafts.

Descemet Stripping Automated Endothelial Keratoplasty With a Retention Suture: Description of a Technique for Patients at High Risk of Graft Detachment.

PURPOSE: To evaluate the utility, safety, and efficacy of a parallel or cloverleaf retention suture in Descemet stripping automated endothelial keratoplasty that does not penetrate donor tissue and can be removed at the slit lamp for patients at high risk of graft detachment. METHODS: Data were prospectively collected over 9 years from patients who received a retention suture. Indications for use of a retention suture included difficulty with postoperative positioning, abnormal intraocular anatomy including glaucoma tube shunts, trabeculectomies, anterior chamber intraocular lens implants, previous vitrectomy, aniridia, and aphakia, or history of previous graft detachment. RESULTS: Of 128 surgeries, 12 (9.4%) required additional intervention for graft reattachment (rebubble). Overall, 120 grafts (93.8%) remained clear and attached either after surgery with a retention suture or after rebubble procedures. Mean endothelial cell density at 1 year was 1840 cells/mm, and mean endothelial cell density loss was 37.3%. CONCLUSIONS: A cloverleaf or parallel retention suture in conjunction with Descemet stripping automated endothelial keratoplasty seems to reduce the risk of detachment in high-risk patients, while maintaining adequate cell density and graft clarity at 1 year.

Preloaded Descemet Membrane Endothelial Keratoplasty Donor Tissue: Surgical Technique and Early Clinical Results.

PURPOSE: To describe the technique, advantages, and early complication rates of using Descemet membrane endothelial keratoplasty (DMEK) donor tissue that is prestained and preloaded into an injector at the eye bank and delivered in a storage medium to the surgeon for transplantation 1 to 2 days later. METHODS: A total of 111 eyes with endothelial failure underwent DMEK using donors that were prestripped, prestained, S-stamped, and preloaded into a Straiko modified Jones tube and delivered in an Optisol-filled viewing chamber 1 to 2 days later. Scroll tightness, time to unscroll and center the tissue, postoperative rebubble rate, and graft failure rate were recorded. Endothelial cell density was measured at 3 and 6 months. RESULTS: All tissues remained well stained with easy visualization at the time of surgery (n = 111). The mean scroll tightness was 2.2 (range: 1-4). The mean time to center and unscroll the tissue was 3.5 minutes (range: 0.5-11.25 min). There was no primary graft failure. There were 16 cases with the placement of another bubble postoperatively (with a 14.4% rebubble rate). Of those 16 cases, 2 required a second rebubble. Endothelial cell loss at 3 and 6 months postoperatively was 26.7% (n = 63 eyes) and 30.9% (n = 67 eyes), respectively. CONCLUSIONS: This is the first report of the clinical use of prestained, preloaded tissue for DMEK. The characteristics and handling of the tissue were not different from those of surgeon-loaded tissue. Because punching, staining, and loading the graft intraoperatively is not necessary, the surgery time and risk of damaging donor tissue are reduced when using preloaded tissue.

Clinicopathologic correlation of textural interface opacities in descemet stripping automated endothelial keratoplasty: a case study.

PURPOSE: The aim of this study was to describe the clinicopathologic correlation of textural interface opacities (TIOs) in a Descemet stripping automated endothelial keratoplasty (DSAEK) donor button after its removal. METHODS: A 75-year-old woman underwent combined phacoemulsification with intraocular lens placement and DSAEK in her right eye. She had TIOs 1 week postoperatively and continued to have poor visual acuity 8 months postoperatively. The original DSAEK graft was removed, and a repeat DSAEK procedure with a new donor disc was performed. A control corneal button was obtained from a 79-year-old woman who suffered chronic rejection and had a failed DSAEK. Both corneal specimens were sent for light and electron microscopy. RESULTS: Light microscopy of the donor tissue from the patient with TIOs showed stromal irregularities projecting from the cut anterior surface and the expected decrease in the endothelial cell density associated with the procedure and with artifacts. Electron microscopy examination showed irregular collagen fibrils of varying lengths at the stromal surface. Light and electron microscopy examination of the donor tissue from the control patient showed a smooth anterior stromal surface without projecting collagen fibrils. CONCLUSIONS: The histopathology of the endothelial disc from the patient with TIOs demonstrated variably irregular lamellae that extended from the anterior donor corneal stromal surface. These extending lamellae were absent on the anterior stromal surface of the control corneal disc, suggesting that they are one possible cause of TIOs and the subsequent suboptimal best-corrected visual acuity and quality of vision experienced by a subset of DSAEK-operated patients.