Clinical Outcomes and Endothelial Cell Density After Descemet Membrane Endothelial Keratoplasty Using Peripherally-trephinated Donor Tissue (DMEK-pD) in Fuchs Endothelial Corneal Dystrophy

Outcomes of Descemet Membrane Endothelial Keratoplasty Using Cornea From Elderly Donors Aged 80 Years and Older: In the Aftermath of Current Donor Shortage

PURPOSE

The purpose of this study was to report the outcomes of Descemet membrane endothelial keratoplasty (DMEK) using corneas from elderly donors aged 80 years and older.

METHODS

Eighty eyes of 78 patients who underwent DMEK-only or DMEK combined with cataract extraction (triple-DMEK) with surgeon-prepared graft between April 2016 and March 2020 were reviewed. Corrected distance visual acuity, endothelial cell density (ECD), and endothelial cell loss after 6 months, 1 year, and 2 years were analyzed.

RESULTS

The mean donor age was 83.6 ± 3.7 years (range: 80-100 years), and the mean donor ECD was 2889 ± 177 cells/mm 2 (range: 2604-3460 cells/mm 2 ). The mean recipient age was 67.2 ± 6.9 years (range: 60-89 years), and the mean follow-up was 21 ± 11 months (range: 6-52 months). The mean corrected distance visual acuity improved from a preoperative value of 1.36 ± 0.67 logarithm of the minimum angle of resolution to 0.22 ± 0.18 at 6 months (n = 75), 0.21 ± 0.2 at 1 year (n = 64), and 0.23 ± 0.3 logarithm of the minimum angle of resolution at 2 years (n = 41), respectively ( P < 0.001). In 72 eyes (96%), the graft remained transparent until the last follow-up visit. The mean postoperative ECD was 2073 ±336 (n = 75), 1951 ± 379 (n = 65), and 1807 ± 431 cells/mm 2 (n = 41) at 6 months, 1 year, and 2 years, respectively. Five eyes (6.7%) had donor detachments of which 4 required rebubbling. Two grafts failed after 1 year, and 2 eyes (2.6%) had graft rejection, of which 1 eye was reverted successfully by medical management.

CONCLUSIONS

Cornea from elderly donors aged 80 years and older with good selection criteria may be considered for DMEK with successful outcomes. For India and other countries with unmet tissue needs, every best single cornea counts.

Utilization rate and usage patterns of phakic and pseudophakic donor corneas recovered by the Singapore Eye Bank

PURPOSE

To compare the utilization rate and usage patterns of pseudophakic and phakic donor corneas recovered by the Singapore Eye Bank.

METHODS

Records of local donor corneas recovered by the Singapore Eye Bank from 2012 to 2017 were examined. Corneas that were deemed suitable for clinical use were stratified into phakic and pseudophakic groups. We examined the basic demographic pattern of both groups and the initial type of surgery/ies that the corneas were suitable for based on tissue parameters such as time from harvesting, stromal clarity, the clear central corneal area, the presence of Descemet's membrane tears or defects, and endothelial cell density and quality. We also identified the types of corneal grafts that the corneas were eventually used for; Penetrating Keratoplasty (PK), Anterior Lamellar Keratoplasty (ALK), Endothelial Keratoplasty (EK). Finally, the overall utilization rates for each group were determined.

RESULTS

A total of 986 corneas deemed suitable for transplant were analyzed, 908 (92%) were phakic and 78 were pseudophakic (8%). The average age of pseudophakic donor corneas was (65 ± 8 yrs. old) and there was a slight male preponderance for both groups (55%). Age adjusted analysis of pseudophakic corneas showed the endothelial cell density (ECD) (mean: 2327 ± 47.1 cells/mm2) and clear area (mean: 7.0 ± 0.7 mm) were lesser than phakic corneas. The percentage of pseudophakic corneas that were of EK standard (ECD >2500 cells/mm2) were lower compared to phakic corneas (37% and 77% respectively, p < 0.001). There was significant correlation between previous cataract surgery and the endothelial cell count of the donor corneas (p < 0.001), and regression analysis also showed a strong association of ECD with cataract surgery in reference to non-cataract surgery (-478.8 (95% CI-576.9 to -380.7). The overall utilization rate for pseudophakic corneas was 58% compared to that of phakic corneas at 83%. The most common reason for pseudophakic corneas not to be utilized was due to the presence of Descemet's membrane (DM) tears or defects under the main or side port incision created during phacoemulsification (30%). Phakic corneas were used primarily for optical grafts 84% (mainly EK) while pseudophakic corneas were used mostly for therapeutic/tectonic grafts 47% (mainly ALK or patch grafts).

CONCLUSION

Compared to phakic donor corneas, pseudophakic corneas generally have lower overall tissue quality leading to lower uptake by surgeons and lower utilization rates. Eye banks must continuously refine their donor acceptance criteria and engage surgeons to optimize utilization of each recovered tissue.

Marking DMEK Grafts Using Bandage Contact Lens Interface Technique: Doubling the Utilization During the Acute Shortage of Donor Corneas

PURPOSE

The purpose of this study was to describe a novel bandage contact lens (BCL) interface technique for marking the Descemet membrane endothelial keratoplasty (DMEK) graft so that a single donor cornea can be used effectively for 2 recipients during acute shortage.

METHODS

This was a retrospective comparative case series. In group A, 37 eyes underwent DMEK using a graft marked by the [DOUBLE HIGH-REVERSED-9 QUOTATION MARK]BCL interface technique" that was compared with 49 conventional DMEK grafts marked through the stromal window (group B). In group A, a resized BCL with a central 3-mm hole with the concavity up was placed between the stroma and peeled-off DM. This BCL with DM was flipped for S-stamping on the DM side. Final trephination was performed on a second Teflon block. The remaining anterior lamellar tissues of group A were used on the same day for other keratoplasty procedures. Endothelial cell density (ECD) and endothelial cell loss between the 2 groups were compared after 3 and 6 months.

RESULTS

The ECD at 3 months in group A (n = 35) versus group B (n = 45) was 2228 ± 270/mm2 versus 2302 ± 254/mm2 (P = 0.48), and the ECD at 6 months (n = 23 and 22) was 2058 ± 324/mm2 versus 2118 ± 260/mm2 (P = 0.72). The corresponding endothelial cell loss was 23.3% ± 6.8% versus 20.3% ± 6.1% (P = 0.18) at 3 months and 29.1% ± 8.4% versus 26.7% ± 8.0% (P = 0.34) at 6 months. Among anterior tissues of group A, 17 (45.9%) were used for deep anterior lamellar keratoplasty, 18 (48.6%) were used for larger therapeutic and tectonic grafts, and 2 were used as keratoprosthesis carriers. Donor detachment rate (8.6% vs. 8.9%) was similar in both groups without primary graft failures.

CONCLUSIONS

The BCL interface technique is a simple and safe technique for stamping DMEK grafts. Anterior corneal tissues can be used for additional keratoplasties during donor shortage.