Abstract
Purpose:
Current techniques to prepare the donor tissue for Descemet’s Membrane Endothelial Keratoplasty (DMEK) are extremely technically challenging and not easily taught or reproduced. This study aims to assess the ability, ease, and reproducibility of dissecting Descemet’s membrane from donor corneal tissue using the Lubniewski Micro Needle (Fischer Instruments, St. Louis, MO).
Methods:
Ten human donor corneoscleral buttons were placed on a cutting block with the endothelial surface facing up. Four investigators at various levels of ophthalmic surgical training participated in the study. A PC-7 needle (Alcon, Fort Worth, TX) was partially inserted posterior to Schwalbe’s line and withdrawn to create a short lamellar tunnel. The tip of the PC-7 needle was inked in order to aid in identifying the location of the tunnel after withdrawing. A Lubniewski Micro Needle on a 3-cc syringe containing Optisol solution was introduced into the tunnel and advanced into the posterior corneal stroma just underneath Descemet’s membrane. Optisol was slowly injected to create a translucent bubble of fluid that dissected Descemet’s membrane from the posterior stroma. Spectral domain anterior segment OCT (Optovue, Fremont, CA) was used to evaluate the thickness of the dissected layer. The corneoscleral buttons were fixed in formalin and trephined with a 9 mm corneal punch. The dissected layer of tissue was detached from the cornea, stained with hematoxylin and eosin as well as periodic acid-Schiff, and analyzed under light microscopy.
Results:
All ten specimens revealed complete dissection of Descemet’s membrane and endothelium from the posterior corneal stroma. Anterior segment OCT and histology confirmed that Descemet’s membrane was free of all posterior stromal attachments. Four different surgeons at various levels of surgical experience participated in the study and all were able to reproduce complete dissection of Descemet’s membrane. Two Descemet’s ruptures were encountered in the study during introduction of the needle and injection of fluid; however, these ruptures were peripheral and not involving the central 9 mm of the cornea.
Conclusions:
This technique is an efficient, cost-effective, and reproducible method to safely dissect Descemet’s membrane and endothelium from donor corneal tissue for DMEK. Viability of the endothelial cells was not assessed in this study and would be a valuable next step.
Keywords: 481 cornea: endothelium