The Ongoing Puzzle of the Biological Behavior of Cornea Guttae

Donor Corneal Endothelial Cell Maturity and Its Impact on Graft Survival in Glaucoma Patients Undergoing Corneal Transplantation

PURPOSE

To examine corneal graft survival via corneal endothelial cell density (ECD) and corneal endothelial cell loss (ECL) at 5 years post-transplantation in the eyes of patients with and without a history of undergoing glaucoma surgery according to the maturity of the donor corneal endothelial cells.

DESIGN

Prospective cohort study.

METHODS

This prospective cohort study included 17 patients with glaucoma and 51 patients without glaucoma who underwent Descemet's stripping automated endothelial keratoplasty or penetrating keratoplasty at the Baptist Eye Institute, Kyoto, Japan, between October 2014 and October 2016. Human corneal endothelial cells were cultured from residual peripheral donor cornea tissue, and the maturity of the cells was evaluated by cell surface markers (ie, CD166+, CD44-/dull, CD24-, and CD105-) using fluorescence-activated cell sorting. Kaplan-Meier analysis or the chi-square test was used to assess the rate of successful corneal graft survival post-transplantation.

RESULTS

At 36 months postoperatively, the mean ECD and ECL in the glaucoma-bleb eyes were 1197 ± 352 cells/mm2 and 55.5% ± 13.9% in the high-maturity group and 853 ± 430 cells/mm2 and 67.7% ± 18.1% in the low-maturity group, respectively. Kaplan-Meier analysis revealed that at 5 years postoperatively, the overall rate of survival was 45%, that is, 100% in the high-maturity group and 25% in the low-maturity group (P < .05).

CONCLUSIONS

The findings in this prospective cohort study revealed that the use of donor corneal grafts containing mature-differentiated corneal endothelial cells could maintain the survival of the transplanted graft for a long-term period, even in patients with a history of undergoing glaucoma surgery.

Superiority of Mature Differentiated Cultured Human Corneal Endothelial Cell Injection Therapy for Corneal Endothelial Failure

PURPOSE

To investigate the safety and efficacy of cultured human corneal endothelial cell (hCEC) injection therapy with mature differentiated (mature) cell subpopulations (SPs) for corneal endothelial failure (CEF).

DESIGN

Comparative, interventional case series.

METHODS

This study involved 18 eyes with CEF that underwent cultured hCEC injection therapy, categorized into 2 groups: (1) 11 eyes administered a relatively lower proportion (0.1 to 76.3%) of mature cell SPs (group 1 [Gr1]), and (2) 7 eyes administered a relatively higher proportion (>90%) of mature cell SPs (group 2 [Gr2]). From 1 week to 3 years postoperation, corneal endothelial cell (CEC) density (CECD), central corneal thickness (CCT), and best-corrected visual acuity (BCVA) were recorded, and the CEC parameter's "spring constant" was calculated. The proportion of mature SPs was evaluated by fluorescence-activated cell sorting analysis based on cell-surface markers.

RESULTS

At 3 years postoperation, corneal restoration with improved BCVA was attained in 10 of the 11 Gr1 eyes and all Gr2 eyes, the median CECD in Gr2 (3083 cells/mm²; range, 2182-4417 cells/mm²) was higher than that in Gr1 (1349 cells/mm²; range, 746-2104 cells/mm²) (P < .001), and the spring constant verified the superiority of the mature cultured hCECs. From 24 weeks through 3 years postoperation, the median percentage of CECD decrease was 3.2% in Gr2 and 23.6% in Gr1 (P < .005). CCT recovery was prompt and constant in Gr2, while diverse in Gr1. No adverse events were observed.

CONCLUSION

Our findings showed that mature cell SPs for hCEC injection therapy provide rapid recovery of CCT, better CECD, and low CECD attrition over 3 years postsurgery.