Immediate Postoperative Intraocular Pressure Changes After Anterior Chamber Air Fill in Descemet Membrane Endothelial Keratoplasty

Purpose: To monitor the intraocular pressure (IOP) changes immediately after anterior chamber air tamponade in Descemet membrane endothelial keratoplasty (DMEK). Methods: Twenty-four patients undergoing DMEK and 16 patients undergoing rebubbling after DMEK were enrolled (n = 40). All DMEK patients had inferior iridectomy and nearly full intracameral air tamponade with an aimed IOP of 25 mm Hg at the end of surgery. The IOP was measured at 1, 2, 3, 5, 12, 24 hours and 1 week postoperatively. Results: After anterior chamber air fill in DMEK, the IOP increased from preoperative baseline, 12.1 ± 2.9 mm Hg, to 26.3 ± 4.7 mm Hg, P < 0.001. Mean IOP was significantly elevated in the first 2 hours, 19.4 ± 10.5 mm Hg and 17.0 ± 7.4 mm Hg, P = 0.007 and 0.006, respectively. Then, it lowered to the baseline level, 14.0 ± 4.7 mm Hg, P > 0.05, and remained stable during follow-ups. An asymptomatic IOP elevation above 30 mm Hg was detected in 3 patients (12.5%) within the first 2 hours. None had preexisting glaucoma. Most episodes could be controlled by antiglaucoma medications and upright positioning. The pattern of IOP changes after rebubbling was similar to that after DMEK but the IOP dropped sharply to the baseline level after 1 hour and had no incidence of IOP elevations beyond 30 mm Hg. Conclusions: Adequate inferior iridectomy greatly alleviates the risk and severity of acute IOP rises after nearly full anterior chamber air tamponade in DMEK. Standard IOP adjustment at the end of DMEK surgery with postoperative IOP monitoring especially in the first 2 postoperative hours is advisable when there is no postoperative default air release.