High Resolution Optical Coherence Tomography Guided Donor Tissue Preparation for Descemet's Membrane Endothelial Keratoplasty Using Reverse Big Bubble Technique

Purpose: To assess the feasibility of High Resolution Spectral Domain Optical Coherence Tomography (HR-SDOCT) to guide donor tissue preparation in Descemet's Membrane Endothelial Keratoplasty (DMEK) using the reverse big bubble technique.

Methods: Three corneo-scleral discs were included in this ex-vivo experimental study. A 27 gauge cannula was introduced into each cornea at the periphery by 3 different surgeons. Each surgeon attempted to achieve the ideal depth (pre-descemetic plane) of the tip of the cannula for air injection to produce the reverse big bubble in order to separate Descemet's membrane (DM) from posterior stroma. A supine OCT system built at the Ophthalmic Biophysics Center of the Bascom Palmer Eye Institute was used to estimate in real-time the depth reached by the tip of the cannula in the posterior stroma during tissue preparation.

Results: After air injection, one successful big bubble was obtained, while each of the other corneo-scleral discs had intrastromal emphysema and DM perforation. On HR-SDOCT evaluations, artifacts were noticed at the tip of the cannula. The successful big bubble demonstrated separation of DM and stroma without intrastromal hyperreflectivity. Emphysema was visualized on the HR-SDOCT as a hyperdense intrastromal area shadowing the posterior structures of the anterior chamber.

Conclusion: HR-SDOCT guided reverse big bubble technique may be a useful method to prepare donor tissue in DMEK. Further improvements in HR-OCT technology are needed to improve this promising technique.