Effect of temperature variation on the corneal endothelial cell during femtosecond laser-assisted cataract surgery compared with conventional phacoemulsification cataract surgery: A prospective study

To evaluate whether the corneal endothelium experiences increased temperatures and thermal damage during femtosecond laser-assisted cataract surgery (FLACS), we performed comparative in vivo studies. These studies compared FLACS with conventional phacoemulsification cataract surgery (CPS) systems. In this study, 410 eyes with grade II or III nuclear sclerotic cataracts undergoing either CPS (n = 213) or FLACS (n = 197) were examined. All eyes received balanced salt solution at 21°C or 29°C during phacoemulsification. In FLACS, a SoftFit patient interface (PI) was used at 21°C or 29°C. The surface temperature and intraocular temperature were recorded using a thermometer. Postoperative therapies were identical across all groups. Endothelial cell loss (ECL) was measured with a specular microscope before and 1 week post-surgery. The average temperature in the anterior chamber was similar after FLACS and CPS. FLACS used less cumulative dissipated energy (CDE) and resulted in lower ECL than CPS. However, no significant difference was found in mean CDE or ECL between subcohorts with different PI temperatures. The same applied to subcohorts with different balanced salt solution temperatures. At a PI temperature of 21°C, both anterior chamber temperature and ECL were lower in the first 10 minutes after femtosecond laser (FL) treatment than afterward. FL does not cause temperature increases in the anterior chamber. In contrast, FLACS reduces CDE and ECL compared with CPS. Additionally, lowering PI temperature and performing FL before phacoemulsification - especially during the first 10 minutes - may help protect the corneal endothelium.