Yutaka Ishino

Purpose. It would be advantageous if cultivated human corneal endothelial cells (cHCECs) could be transplanted for the treatment of diseases caused by corneal endothelial disorders. To achieve this, a matrix that can serve as a carrier for cHCECs is needed. The present study was conducted to examine the feasibility of using amniotic membrane (AM) as a carrier for this application. methods. HCECs obtained from peripheral corneal tissue were cultivated, passaged, and transplanted onto denuded AM. The cell density and morphology of the resultant cHCECs on AM were examined by light, scanning electron, and transmission electron microscopy. To determine whether these cHCEC sheets on AM carrier were functional in vivo, the cHCEC sheets on AM were transplanted onto rabbit corneas whose Descemet’s membrane and endothelial cells had been completely removed. After transplantation, the corneal appearance was examined by slit lamp biomicroscopy, and corneal thickness was measured daily by pachymetry. At 7 days after surgery, the grafts were examined by light, scanning electron, and transmission electron microscopy. results. The density of the cHCECs on AM was greater than 3000 cells/mm². Morphologically, the cHCEC sheets consisted of a fairly continuous layer of flat squamous polygonal endothelial cells that appeared uniform in size with tightly opposed cell junctions in vitro and in vivo after transplantation. The corneas that received transplanted cHCEC sheets had little edema and retained their thinness and transparency. conclusions. The cell density and morphology of cHCECs on AM were similar to those of normal corneas, and cHCECs on AM were functional in vivo. These results indicate that AM maintains HCEC morphology and function and could serve as a carrier for cHCEC transplantation.

We report 6 cases of herpes simplex keratitis after ophthalmic surgery, in eyes without clinical history of herpes simplex keratitis. These cases comprised 6 patients examined at our hospital between April 1992 and November 2001. Past operations were keratoplasty in 5 eyes and cataract surgery in 1 eye. Clinical findings and predisposing factors were evaluated retrospectively. The period between herpetic epithelial keratitis onset and ophthalmic surgery ranged from 1.5 to 79 months. Predisposing factors included corticosteroid therapy and operative wound. The herpetic epithelial lesions were dendritic ulcers in 2 eyes, geographic ulcer in 1 eye, and atypical epithelial lesions in 3 eyes; in all cases, herpes simplex virus (HSV)-DNA was detected by polymerase chain reaction (PCR) in tear fluid. All herpetic epithelial lesions healed with oral and topical acyclovir. When corticosteroids are used following ophthalmic surgery, physicians should be alert to the possibility of herpetic epithelial keratitis, even in patients with no clinical history of herpes simplex keratitis. PCR detection in tear fluid is helpful in diagnosing this disease.

The expression of Fas ligand (FasL) in donor corneal tissue has been thought to contribute to the prolonged survival of orthotopic corneal allografts. However, in solid organ transplantation, FasL gene-transfected tissues have been reported to lead to graft destruction through neutrophil recruitment. We wished to examine whether transfection of mutant FasL cDNA, which produces only membrane-binding forms of FasL because of its cleavage site, prolonged corneal allograft survival in mice. Donor corneal tissues were transduced with two adenovirus vectors containing human mutant FasL cDNA (AxCALNmFasL) and Cre recombinase (AxCANCre). Donor corneal tissues were then transplanted orthotopically onto recipient mice, and graft clarity was examined by slit lamp microscopy. We found that donor corneal grafts transfected with mutant FasL were intensely opaque for 1-2 weeks after grafting, when grafts without transfection remained clear. Histological examination revealed polymorphonuclear cell infiltration in the transfected grafted tissue. Moreover, mutant FasL transduced to donor tissues was found to exert its effects by binding to host, rather than donor Fas molecules, since corneal grafts with mutant FasL survived as long as those without transfection only when host animals, but not donor animals, lacked Fas molecules. Our results indicate that membrane-binding FasL over expression in donor cornea does not prolong corneal allograft survival; indeed, it causes rapid graft destruction.