Comparison of Artificial Anterior Chamber Internal Pressures and Cutting Systems for Descemet's Stripping Automated Endothelial Keratoplasty

Abstract

PurposeTo optimize methods of preparing donor cornea tissue for Descemet's stripping automated endothelial keratoplasty (DSAEK), we compared five experimental conditions with different internal pressures and cutting systems.MethodsThe artificial anterior chamber internal pressure (IP) was set at 100 or 200 mm Hg. The microkeratome cut was performed with or without an artificial chamber pressurizer (ACP), using a CBm turbine (CBm) or one use-plus automated (OUP-A). Thirty human research corneas were divided into five groups, and compared after the cut with donor tissue quality parameters, including cutting depth, graft uniformity, cell evaluation, and smoothness of the stromal surface.ResultsThe smallest variation in mean cut depth was observed in the condition, which had IP of 200 mm Hg used ACP and OUP-A. In experimental groups cut using CBm, significantly more consistent thicknesses were made at an IP of 200 than 100 mm Hg. There were no statistically significant differences among the groups in either endothelial cell density or cell viable assay results after cuts. Using an IP of 200 mm Hg with ACP and CBm produced the roughest stromal surface, and the roughness grading scores showed a positive correlation with the percentage of cut depth.ConclusionsAn IP of 200 mm Hg was the best setting for DSAEK grafts with high predictability of cut depth and uniformity of graft thickness without endothelial cell damage.Translational RelevanceFor successful DSAEK, it is recommended that a set internal pressure of 200 mm Hg be used during microkeratome cutting for donor tissue preparation.

The predictability of graft thickness for Descemet’s stripping automated endothelial keratoplasty using a mechanical microkeratome system

“…Despite the correlation between the post-cut central graft thickness and the central donor corneal thickness, we identified variations in the post-cut central graft thickness even within the identical central donor corneal thickness range. The cutting speed 12 , 13 and IP settings 10 , 14 affect the thickness of the cut. In CCEB, DSAEK grafts cut by ACP/OUP-A displayed a narrower thickness range and were cut with higher accuracy than grafts from conventional manual cutting (Supplemental Fig.…”

“…All donor tissues were stored at 4 °C and returned to room temperature before the microkeratome cut. The tissues were dissected by the mechanical microkeratome system using an artificial chamber pressurizer (ACP, Moria, Antony, France) and one use-plus automated (OUP-A, Moria) 10 . Briefly, for the ACP/OUP-A automatic protocol, we set the initial IP at 200 mmHg and constantly maintained it with ACP during the microkeratome cut.…”

“…Manual microkeratome cutting produces grafts of variable thickness because of the difficulty in maintaining constant conditions, and its results are less reproducible 8 , 9 . Recently, some operators have prepared DSAEK grafts using a mechanical microkeratome system, in which a pass is automatically performed by the instrument, while a constant artificial chamber internal pressure (IP) is maintained 2 , 10 , 11 . Thus, we hypothesized that it was possible to identify other factors affecting the cutting thickness.…”

Efficacy of Femtosecond Laser-Assisted Capsulotomy: Experimental Evaluation Using the Zonular Dehiscence Model

“…A 22-gauge needle attached to an artificial chamber pressurizer (ACP, Moria SA, Antony, France) was inserted from the equator into the vitreous cavity to maintain the pressure at 25 mm Hg. 10 …”

“…A 22-gauge needle attached to an artificial chamber pressurizer (ACP, Moria SA, Antony, France) was inserted from the equator into the vitreous cavity to maintain the pressure at 25 mm Hg. 10 FL-assisted capsulotomy with a 5-mm diameter was created in the capsular center. The laser settings were as follows: energy = 10 μJ; spot separation = 5 μm; layer separation = 5 μm; and the anterior or posterior delta was increased to 1000 μm.…”