Impact of postoperative intraocular pressure elevation on graft endothelial cells in non-preexisting glaucoma eyes undergoing descemet membrane endothelial keratoplasty: a cohort study.

BACKGROUND

Descemet membrane endothelial keratoplasty (DMEK) has become the dominant keratoplasty procedure. However, the impact of high intraocular pressure (IOP) on the DMEK prognosis in patients without preexisting glaucoma remains unknown.

METHODS

Non-glaucoma patients who underwent DMEK in Peking University Third Hospital between July 2017 and March 2023 with a follow-up duration longer than six months were included in this cohort study. Eyes were divided into three groups: Group A) normal IOP; Group B) early IOP elevation (IOP ≥ 30 mmHg or increase of more than 10 mmHg from baseline within 3 days); Group C) intermediate-term IOP elevation (IOP > 21 mmHg or increase of more than 10 mmHg from baseline after 14 days postoperatively). The postoperative IOP, endothelial cell density (ECD), central corneal thickness (CCT), best-corrected visual acuity (BCVA) and rate of graft failure were analysed.

RESULTS

Forty-seven eyes from forty-seven patients were included. Thirty-seven eyes were bullous keratopathy, and ten were Fuchs endothelial corneal dystrophy. Twenty-five eyes were classified as Group A, six as Group B and sixteen as Group C. The mean peak IOP was 49.00 ± 4.99 mmHg in Group B eyes and 31.89 ± 11.75 mmHg in Group C eyes. The postoperative BCVA significantly differed from that before surgery (P < 0.001). The ECD at 3 months after surgery in eyes with intermediate-term IOP elevation was lower (P = 0.032). Four eyes with intermediate-term IOP elevation developed graft failure (P = 0.001).

CONCLUSIONS

Intermediate-term IOP elevation after DMEK may reduce the graft ECD and lead to graft failure within six months after surgery. However, early IOP elevation had no effect on the prognosis. Careful IOP monitoring and intermediate-term IOP management should be conducted for graft protection.