摘要:

This paper describes the surgical results in 163 patients in whom intraocular lenses (IOL) had been implanted, exchanged, or removed during penetrating keratoplasty (PKP). They were divided into the following groups: 1) PKP, cataract extraction, and IOL implant; 2) PKP in aphakia and IOL implant; 3) PKP and IOL exchange; 4) PKP and IOL removal. In all groups clear transplants were obtained in over 92% of the cases, with best optical and visual results obtained in cases of Fuchs' dystrophy with cataract extraction and IOL implant (98% clear grafts and vision better than 20/40 in most cases). There were no significant differences in graft transparency and in the magnitude of visual acuity improvement between cases of pseudophakic edema with IOL replaced or removed at the time of surgery, and cases of aphakic edema with secondary IOL implant. Good surgical results are attributed to the use of young donor tissue with short time of storage, microsurgical techniques, and the use of sodium hyaluronate (Healon) for the protection of graft endothelium.

ISSN:0277-3740    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

We report on the evolution of ultrastructural modifications in bovine and rabbit corneal sections after in vitro swelling. The number of stromal fibers decreases with time during swelling. The fact that swelling occurs more rapidly in the center of a lamellae than near the interlamellar spaces indicates that there is a heterogeneous distribution of interfibrillar matrix components and that corneal inhibition mechanisms vary according to the number of lamellaes.The appearance during swelling of periodic striations of collagen fibers and of an irregular network constituted of filaments and granules in the interfibrillar spaces suggests that corneal collagen fibers are covered by a pleated proteoglycan-glycoportein substance that is unrolled during swelling. The filaments seem to be linked to collagen via dense granules located on fibers. The distance between the granules is 643 Å. A definite correspondence between the distribution of these linking granules and the periodic striations of collagen cannot be determined. Other granules of undetermined chemical nature seem to link only filaments in the interfibrillar space.

ISSN:0277-3740    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Because of controversy surrounding the expression of ABO blood group (ABH) antigens (which may act as transplantation antigens) in human cornea, we examined the expression of these antigens in a panel of normal corneas using a highly sensitive avidin-biotin complex immunoperoxidase technique. ABH antigens were expressed by the corneal epithelium from all donors in a pattern consistent with their red blood cell phenotype, but were absent from stroma and endothelium. We also examined the same corneas for cells expressing hematopoietic cell markers in an effort to determine which marrow-derived cells may be contributing (as “passenger leukocytes”) to the immunogenicity of corneal allografts. Scattered cells positive for a pan-hematopoietic cell marker (T29/33) were present throughout all corneas, but no consistent expression was noted of markers for B lymphocytes, monocytes, or NK cells. Adult corneas showed occasional T lymphocytes, predominantly in the limbus. Finally, we looked for the expression by these corneas of a variety of cell-specific and structural antigens, to identify possible relationships between corneal cells and analogous cell populations. We found that corneal endothelial cells expressed one vascular endothelial antigen, (HuEE12), but not another (Factor VIII related antigen), suggesting a possible relationship between corneal endothelium and its immunologically important vascular counterpart. Various structural antigens were found in predicted associations with corneal endothelial, stromal, and epithelial cells. These findings cast new light on the antigens involved in corneal allograft reactions and the immunologic nature of some constituent corneal cells.

ISSN:0277-3740    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Alkali burns of the cornea were made bilaterally in 16 albino rabbits. The eyes were then treated four times a day in a masked fashion with a solution either of fibronectin (250 μUg/ml) plus gentamicin (1.5 mg/ml) or of gentamicin (1.5 mg/ml) plus hydroxypropyl methylcellulose (Tears Naturale). The eyes were examined daily in a masked manner for evidence of a corneal epithelial defect. On days 6–14, the fibro-nectin-treated eyes had more healed corneal defects (p < 0.05, McNemar's test for matched pairs) than the control eyes. Fibronectin aided the healing of corneal alkali burns by decreasing the peeling back of the healing epithelium and by allowing re-epithelialization if peeling back had occurred. These properties of fibronectin helped to preserve a stable, intact corneal surface.

ISSN:0277-3740    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The validity of using the aqueous humor lactate concentration as an indicator of corneal lactate production was tested. For this purpose, ten rabbits wore non-gas permeable contact lenses on one eye for 12 hours. Aqueous humor and corneal extracts were assayed for lactate by means of an enzymatic technique. The contact lens wear caused a limited increment in the corneal lactate concentration, but no change was recorded in the aqueous humor. We therefore conclude that the corneal lactate production has a negligible effect on the lactate concentration in aqueous humor. However, significant individual variations in lactate levels were recorded in the present study, as in earlier ones.4–5 Insufficient specificity in the currently used techniques for lactic acid concentration determination may in part explain this.

ISSN:0277-3740    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Corneal erosions were produced by iodine vapor application in rabbit and guinea pig eyes. The corneal erosion of each eye was photographed four times daily after fluorescein staining and the erosion area measured planimctrieally.Thirty-six percent of the corneal epithelium was destroyed in rabbits and 67% in guinea pigs. In guinea pigs, wound healing was delayed significantly by Spersadex® Totocortin®, and benzalkonium chloride (BAK) 0.01% in the experimental eye. Spersadex® also caused a significant delay in wound healing in the nontreated contralateral eye. Cyclosporin A 2% and Oculotect® had no influence on epithelial wound healing. An 8-day pretreatment of guinea pig eyes with cyclosporin A or Spersadex® had no further influence on the epithelial wound-healing rate.

ISSN:0277-3740    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Using an invitrofluorophotometric technique, we studied the effect of postmortem storage duration on the endothelial barrier function of porcine corneas. A marked decay in endothelial barrier function was demonstrated that correlated with duration of storage. This decay appears to be nearly complete after 2 weeks of storage. This loss of barrier function correlated grossly with ultrastructural changes demonstrated on scanning electron microscopy.

ISSN:0277-3740    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

A multifocal progressive infiltration of a corneal graft, which simulated a mycotic keratitis but was repeatedly negative on culture and unresponsive to antibacterial and antifungal therapy, was found upon regrafting to consist primarily of Cram-positive cocci. This bacterial colonization of the corneal graft was associated with epithelialized suture tracks and minimal inflammatory response. The immunosuppressive and bacteriostatic effects of chronic postsurgery low dose steroid and antimicrobial therapy may have played a role in the development of this atypical bacterial infiltrate.

ISSN:0277-3740    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

A serial study was carried out with the scanning electron microscope every 5 h to examine the endothelial alterations that occur when the rabbit cornea remains in the eye after enucleation. The findings are compared with those encountered when the cornea with a scleral rim was removed from the globe immediately after enucleation, immersed in Balanced Salt Solution, and observed at the same time intervals. Our results indicate that this procedure protects the corneal endothelium for at least 20 h.

ISSN:0277-3740    

出版商:OVID    

年代:1985

数据来源: OVID

ISSN:0277-3740    

出版商:OVID    

年代:1985

数据来源: OVID