The "Polish Sign": A Novel Intraoperative Visual Indicator During Descemet Membrane Polishing in Cultured Human...

The aim of this study was to describe a novel intraoperative visual indicator, the "polish sign," which aids safe and effective Descemet membrane (DM) polishing during cultured human corneal endothelial cell (cHCEC; Vyznova) therapy for bullous keratopathy.

Thirty-two consecutive eyes with bullous keratopathy underwent cHCEC injection therapy. After a 1.2-mm limbal incision, the central corneal endothelium and associated abnormal extracellular matrix within an approximately 8-mm zone were gently polished using a Kinoshita-type DM polisher, consisting of a blunt needle covered with a silicone sleeve that allows coaxial irrigation. The polish sign-defined as a transient whitish discoloration at the point of instrument contact-was monitored throughout the procedure. Adequacy of polishing was confirmed intraoperatively by trypan blue staining while the absence of DM detachment was verified using anterior segment optical coherence tomography.

The polish sign was consistently observed in all 32 eyes (100%). In 1 eye with severe stromal haze following failed Descemet stripping automated endothelial keratoplasty, the sign appeared less prominent but remained detectable under oblique slit illumination. Polishing was completed in all eyes without DM rupture or detachment. Ex vivo porcine experiments (n = 3) reproduced a similar transient whitening, although less distinct than in human cases.

The polish sign provides a simple, real-time indicator that enables safe and consistent DM polishing while minimizing the risk of DM injury. Although its visibility may decrease in eyes with dense stromal opacity, adjusting illumination can enhance recognition, suggesting that the sign may have relevance across various endothelial cell-based therapies.