#HUMAN EYEBALLS SERIES#

We used cryopreserved donor corneas without endothelium for the therapeutic penetrating keratoplasty (PKP).

#HUMAN EYEBALLS SERIES#

In our case series reported herein, patients with a variety of primary corneal diseases at a severe stage of perforation underwent therapeutic corneal transplantation to preserve the eyeball integrity. Most recently, experimental studies have shown that the corneal endothelium can regenerate in rat and rabbit eyes. In contrast, ex vivo experiments have suggested that the periphery of the corneal endothelium has a higher regenerative capacity in vitro than the center. Endothelial wound healing in the defect area is accomplished by cell migration and enlargement. Physically, human corneal endothelial cells lack regenerative capacity in vivo. When the corneal endothelial cell density falls below a critical level, the integrity of the endothelial barrier and pump functions is compromised, and corneal endothelial decompensation occurs, manifesting as epithelial bullae, stromal edema, corneal clouding, and severe vision impairment, which can only be reversed by the transplantation of donor cornea with a healthy endothelium. The endothelial cell density decreases slowly and linearly with age and declines rapidly through accidental or surgical trauma, corneal transplantation, and diseases such as diabetes, glaucoma, and endothelial dystrophy. A corneal endothelium with a sufficient cell density helps maintain a normal hydration state and cornea clarity through the functions of a passive barrier and active ion transport. We obtained conclusive evidence that host-derived endothelial cells can regenerate a new endothelium over the endothelium-free graft, which possesses normal functions for corneal clarity and vision recovery.Ĭorneal clarity crucially depends on a relatively dehydrated state for the stroma regulated by the endothelium, a densely packed, single layer of cells on the posterior surface of the cornea. Remarkable vision rehabilitation was achieved in all 18 patients. The regenerated endothelium on the grafts reached a mean cell density of 991 cells/mm 2. Through periodic confocal microscopy, we observed the corneal endothelium’s regenerating process, along with single cells bearing multiple nuclei and cell division-like morphology. Thereafter, we observed gradual and progressive regression and final resolution of the stromal edema, with complete recovery of corneal graft clarity. After the therapeutic penetrating keratoplasty, notable corneal graft edema was observed in all 18 eyes for 1–4 months, and no corneal endothelial cells were detected on the grafts during this period. No viable cells were detected in the cryopreserved corneas. Of these, 18 eyes recovered corneal graft clarity and underwent periodic slit-lamp microscopy, A-scan pachymetry, and in vivo confocal microscopy to observe the clinical manifestations, variations in corneal thickness, and repopulation of the corneal endothelial cells on the donor grafts. To preserve eyeball integrity, we performed therapeutic penetrating keratoplasty using cryopreserved donor tissue without endothelium on 195 consecutive patients who suffered from corneal perforation due to progressive primary corneal disease such as herpes simplex keratitis, fungal keratitis, ocular thermal burns, keratoconus, and phlyctenular keratoconjunctivitis. We evaluated the donor’s cell viability using trypan blue staining and dual staining with calcein acetoxy methyl ester and ethidium homodimer-1. To report on corneal endothelial regeneration, graft clarity, and vision recovery when using endothelium-free grafts.

Human eyeballs