Corneal Endothelial Cell Loss From Anterior Chamber Paracentesis in a Porcine Model

This study aimed to develop a porcine eye model used to predict corneal endothelial cell loss (ECL) associated with anterior chamber paracentesis (ACP) in a healthy adult human cornea. To assess the average wound area and ECL created by needle punctures, a 27-gauge (27G) needle was inserted at the limbus of a porcine eye through the clear cornea and into the anterior chamber. Needle-punctured areas were immediately collected, stained, and photographed with a digital light microscope. The wound areas were quantified in square millimeters (mm²) and then extrapolated to predict ECL in a healthy adult human cornea. The average wound area of the puncture sites was 0.274 ± 0.122 mm². The needle punctures created a larger area of ECL than the observed cross-sectional area of the needle (0.12 mm²). Extrapolating these data to the ECL that would occur in healthy adult human corneas, each 27G corneal needle puncture would damage 685 cells, or 0.21% of the corneal endothelial cell layer. The predicted wound areas for 28G, 30G, and 33G needles were 0.234 mm², 0.163 mm², and 0.072 mm², respectively. The predicted cell loss for a 28G, 30G, and 33G needle stick corresponded to a loss of 586 cells (0.18% of the corneal endothelium), 407 cells (0.13% of the corneal endothelium), and 181 cells (0.06% of the corneal endothelium), respectively. Frequent ACPs following intravitreal injections may be associated with clinically significant ECL; thus, caution is advised, particularly in patients with compromised corneas and low endothelial cell counts.