Effects of ultrasound energy on the porcine corneal endothelium – Establishment of a phacoemulsification damage model

Abstract

Purpose The purpose of this study was to establish a standardized in vitro phacoemulsification damage model for future investigations of the effects of phacoemulsification, surgical devices, protective ophthalmic viscoelastic devices (OVDs), irrigation solutions and other aspects related to cataract phacoemulsification surgery on the corneal endothelium using porcine eyes. Methods Thirty‐four porcine eyes were randomly assigned to three groups (phacoemulsification (n = 13), irrigation (n = 9), control (n = 12)). A total of 5 min of ultrasound energy with intermittent irrigation/aspiration was applied in the eyes of the phacoemulsification group. The eyes of the irrigation group received the identical treatment, but without the application of ultrasound energy. The control group was left untreated. All eyes were then prepared to split corneal buttons followed by 15 days of cultivation. Endothelial cell density (ECD) was assessed blinded on day 15. Results Endothelial cell density declined significantly more until day 15 in the phacoemulsification group (2567 ± 317/267 cells/mm² (median ± 25%/75%‐quartiles), −32.5 ± 7.0/6.4%) compared to the irrigation (3450 ± 350/383 cells/mm², −11.8 ± 5.3/2.6%; p < 0.001) and the control group (3650 ± 288/258 cells/mm², −10.2 ± 3.2/4.6%; p < 0.001). Conclusion The phacoemulsification damage model presented in this study is sensitive to phacoemulsification energy and may reliably be used to investigate various factors involved in phacoemulsification with regard to their influence on corneal endothelial cells. This method is able to replace animal experiments or in vitro cell culture experiments that often do not translate well to the in vivo situation in humans.

Effect of longitudinal and torsional ultrasound on corneal endothelial cells: experimental study in rabbit eyes

“…Furthermore, results in the literature vary widely, along with the methods, making comparisons difficult. 2–12…”

Effect of phacoemulsification fluid flow on the corneal endothelium: experimental study in rabbit eyes

“…Our results seem to be in agreement with those of Kunzmann et al, in a study designed to evaluate the effects of ultrasound energy on the porcine corneal endothelium, through a cell culture model using split corneal buttons. 26 On day 15, they found no statistically significant differences in the endothelial cell density between the control (12 eyes) and the irrigation groups (9 eyes), but there were statistically significant differences between the phacoemulsification group and both the control and the irrigation groups. However, the authors did not state the total irrigating volume used in their study.…”

Phacoemulsification: Proposals for Improvement in Its Application

“…PCR usually occurs toward the end of surgery, when the last quadrant of the nucleus is removed. The main reason for this is that the posterior capsule is more exposed in the final stages of the operation [48].…”

“…If PCR occurs, it is essential to remove the vitreous and residual nuclear fragments from the wound, anterior chamber, or vitreous cavity by anterior vitrectomy or pars plana. The risk of PCR increases in difficult cases, such as small pupil, pseudoexfoliation (PXF), intraoperative floppy iris syndrome (IFIS), and dense cataracts, such as mature, white, intumescent, or black cataracts [48].…”

“…The foldable IOL can play a similar role as the epinucleus and be used as an ideal tool to reduce the risk of PCR when emulsifying the last nuclear quadrant. Therefore, the foldable IOL can be used to improve surgical safety [48].…”