Aims: To evaluate the endothelial quality of corneas obtained from pseudophakic donors and to compare the data with matched phakic controls. Methods: Corneas from eyes with posterior chamber intraocular lenses (PCIOLs) and corneas from phakic eyes (controls) were stored for 1-2 weeks in organ culture and then examined after staining with Alizarin red S. The corneas were divided into two groups according to the duration of storage. Endothelial cell density, the percentage of hexagonal cells, and the coefficient of variation (CV) were determined. Results: There was no statistically significant difference between the 14 PCIOL corneas and the 13 controls stored in organ culture for 7 days for any of the three parameters studied. The mean cell density was 2155 (SD 529) cells/mm 2 in the PCIOL corneas and 2118 (453) cells/mm 2 in the controls (p=0.85). The mean percentage of hexagonal cells was 52% (8%) and 58% (7%), respectively (p=0.06). The mean CV was 0.32 (0.18) in the pseudophakic corneas and 0.39 (0.18) in the controls (p=0.33). Moreover, there was no significant difference between the PCIOL corneas and the controls stored for up to 2 weeks. Conclusions: The corneal endothelium from eyes with PCIOLs appears to be similar to that of phakic eyes after 1-2 weeks in organ culture. This finding suggests that corneas from pseudophakic eyes should not routinely be disqualified for transplantation. The use of at least some pseudophakic corneas may substantially increase the potential donor pool.T he chronic worldwide undersupply of donor corneas for keratoplasty has spawned a search for new sources of tissue. One such potential source, often untapped and sometimes scorned, is the very large pool of pseudophakic eyes. Corneas from such eyes have generally been disqualified as transplantation material on the assumption that the endothelium of an eye which had undergone anterior segment surgery would not meet keratoplasty criteria.Very little has been published on the endothelium quality of pseudophakic corneas. 1 We have therefore performed an in vitro study comparing the endothelium from pseudophakic corneas with that of corneas from phakic eyes. Cell density, the percentage of hexagonal cells, and the coefficient of variation of cell size were analysed. These parameters, which are generally used to define endothelial cell quality, display physiological changes with age.2 But they are also affected by disease (for example, acute glaucoma), contact lens wear, and anterior segment procedures. Endothelial cell damage due to cataract surgery is correlated with surgeon experience, the procedure chosen, the irrigating solutions and viscoelastics used, and the placement of the intraocular lens (IOL). Modern small incision techniques with very brief phacoemulsification times and in the bag IOLs have substantially reduced endothelial cell loss. 4-10 METHODSCorneas from donor eyes with a posterior chamber intraocular lens (PCIOL) and corneas from phakic donor eyes (controls) were stored in organ culture at 35.5°C for up to 2 week...

The number of cataract extractions in Switzerland has tripled since 1981. In 1986, a total of 15,500 cataract operations were performed, 95% of which were accompanied by an intraocular lens implantation. In spite of this tremendous increase pseudophakic bullous keratopathy remains a rare indication for keratoplasties: between 1980 and 1986 only 20 grafts were performed at the authors' clinic for irreversible corneal edema following lens implantation. After implantation of posterior chamber lenses, penetrating keratoplasty for corneal decompensation is performed after a significantly shorter period (one year) than with anterior chamber lenses (three years), or in iris-supported lenses (four years). In Switzerland, the incidence of pseudophakic bullous keratopathy among patients with posterior chamber lenses is around 0.1 to 0.3%. A long-term investigation of the endothelial cell density over a period of seven years in 16 patients with a Binkhorst two-loop lens revealed a quite stable and satisfactory cell density of 1600 cells/mm2.

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Keratoplasty in a calm and avascular cornea usually involves no histocompatibility problem. This is not the case if the recipient cornea is inflamed or vascularized. In such cases, and in those where the donor button has been rejected, HLA matching and particularly the search of HLA DR is important. More than 80 potential kidney donors (160 eyes) are tested each year at Zurich University Hospital. The availability of matched corneas, a certain degree of homogeneity of DR group in our population, and an "anti-DR" action of cyclosporin-A gave us the incentive to perform this study and to place these corneas at the disposal of every Swiss clinic. For this purpose, the HLA groups of high-risk patients must be established and sent to Zurich Eye Bank where these data are regularly compared with matched corneas. Every time an HLA A, B, and especially an HLA DR compatible donor-recipient pair occurs, the clinic involved will be quickly informed. In cases where HLA DR antigens are not compatible, cyclosporin-A should be part of the treatment and in cases where they are compatible, advice would be given to do without it. Since optimal preservation, with the medium used lasts 5 days, there is sufficient time for most corneas with a known HLA group to be grafted on the most compatible recipient.

In a retrospective study, we investigated the survival of transplanted corneal material, which had been sent between 1988 and 1989 from the Zurich Eye Bank to both domestic and foreign physicians and clinics. A questionnaire was used to determine diagnosis, transplant survival, cause of any opacification, the occurrence of problems of epithelialisation, loosening of sutures, as well as vascularization of the host cornea. Of a total of 416 corneas, 327 or 79% could be evaluated. The mean follow-up periods of the various diagnostic groups ranged from 11 to 20 months, with a range of 1 to 35 months. After 18 months, the rate of clear transplants was 96% in the keratokonus group. This rate was significantly better than that of the bullous keratopathy group (77%, p less than 0.013) or that of all other diagnosis groups (72%, p less than 0.001). The difference to the 81% survival rate of the group with Fuchs' endothelial dystrophy was not significant. The most frequent cause of transplant opacification was primary transplant failure. Analysis of possible risk factors further confirmed that transplant opacification occurs more frequent in the presence of vascularization of the host cornea.