No author has a financial or proprietary interest in any material or method mentioned.

In conclusion, implantation of the iStent inject has the ability to lower the postoperative IOP significantly in POAG and PEX after a short follow-up of 6 months with a favorable risk profile. However, limitation of this surgical procedure in phakic PG may exist and need to be investigated in further studies.

ABSTRACT.Purpose: Transplant survival following penetrating keratoplasty is determined to a large extent by the course of endothelial cell density loss. Different influencing factors such as organ culture conditions, surgical trauma, exchange between donor and recipient cells, cell ageing and immune reactions can contribute to endothelial cell loss. The aim of this study was to determine the rate of endothelial cell loss in our patients and to detect dependencies on donor-and recipient-related factors. Methods: Using non-contact specular microscopy, endothelial cell counts were obtained every 6 months from 293 consecutive patients who underwent keratoplasty in our institution between 1996 and 2000. Follow-up time was 36 months. Results: In comparison with the density of donor endothelial cells, the mean endothelial cell loss of patients was 28.8% after 6 months, 39.8% after 12 months and 49% after 24 months. Donor age and initial cell density did not have a significant influence on the course of endothelial cell loss. The lowest rate of endothelial cell loss was associated with patients diagnosed with keratoconus. Conversely, those with preoperative glaucoma had a significantly increased rate of endothelial cell loss (p < 0.05). Conclusions: This study shows that preoperative glaucoma is a major risk factor for increased endothelial cell loss following keratoplasty.

There is no correlation between corneal donor tissue characteristics and the degree of difficulty of unfolding using graft lamella older than 49 years. Therefore, it is not possible to select grafts best suited for DMEK surgery on the basis of donor characteristics when the donor age is above 50 years. Preoperative visual acuity influences the grade of difficulty. The rate of graft detachments and endothelial cell loss increases significantly with a more difficult graft unfolding. The proposed grading system may therefore be relevant for postoperative management.

Purpose In this retrospective study, the visual outcomes and postoperative complications after Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) in the fellow eye were compared. The patient's satisfaction was evaluated. Methods A retrospective analysis of 10 patients, who underwent DSAEK in one eye and DMEK surgery in their fellow eye, was performed. Intraoperative and postoperative complications were recorded. Visual and refractive outcomes were evaluated, including higher-order aberrations (HOA) and contrast thresholds. A subjective questionnaire was used to evaluate patient satisfaction. Results Best-corrected visual acuity (BCVA) was significantly better in DMEK when compared with DSAEK (0.16 ± 0.10 vs 0.45 ± 0.58 logMAR, P ¼ 0.043). Contrast threshold was significantly higher after DMEK than after DSAEK (0.49 ± 0.23 vs 0.25±0.18, P ¼ 0.043). Post-keratoplasty astigmatism, mean spherical equivalent, and HOA did not differ. Nine out of ten patients preferred the DMEK procedure. Visual outcome (4.80 ± 1.14 vs 4.50 ± 1.58, P ¼ 0.257), surgery associated pain and burden (DMEK: 1.30 ± 0.48 vs DSAEK: 1.30 ± 0.48, P ¼ 1.0), estimated time for recovery and rehabilitation (27.6 ± 54.0 vs 24.9 ± 54.8 days, P ¼ 0.173), and mean patient satisfaction (5.40 ± 0.84 vs 5.00 ± 1.05, P ¼ 0.257) were evaluated equally. Conclusion Patient satisfaction reached high, equal values after DMEK and after DSAEK. Nevertheless, patients preferred DMEK, if given a choice. Reasons for the preference may include better uncorrected and BCVA, and especially a better contrast sensitivity.