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.

IOP elevation after DSEK shows a high incidence. Pre-existing glaucoma increased the risk of developing IOP elevation and post-DSEK glaucoma. Although steroid-induced IOP elevation was the most frequent cause and could be treated effectively by tapering down steroid medication; there are other reasons why post-DSEK glaucoma developed. Management by medical treatment results in good visual acuity and graft survival.

Careful and ongoing observation of IOP, especially in the first year after PK, is recommended for patients after penetrating keratoplasty and prompt treatment of IOP elevation when indicated. Early filtering surgery with a better outcome than other surgery procedures should be preferred if medical treatment is not sufficient. Despite anti-glaucoma therapy, good visual outcome can remain beyond expectations despite a clear graft. While there is a potential option for graft exchange, damage to the optic nerve from end-stage glaucoma leads immutably to visual loss.

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.

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.

Ab interno trabeculectomy and iStent® inject were both effective in lowering IOP with a favourable and comparable safety profile in an intraindividual comparative study over a 12-months follow-up in OAG. However, longer follow-up of these patients will be necessary to determine long-term outcomes and to evaluate significant differences.

Incidence of IOP elevation and post-keratoplasty glaucoma after DMEK were low, but regular IOP measurements, especially in eyes with pre-existing glaucoma and bullous keratopathy, are necessary. Steroid-induced IOP elevation was the most frequent reason, and could be treated effectively by tapering down steroid medication or changing the steroid drug. Development of peripheral anterior synechiae after DMEK occured rarely. Therefore, the risk for IOP elevation and especially post-DMEK keratoplasty was reduced compared to PK and DSEK. In all cases, successful management by medical treatment was possible, and resulted in good visual acuity.