How to Avoid an Upside-Down Orientation of the Graft during Descemet Membrane Endothelial Keratoplasty?

Abstract

Purpose. Incorrect anterior-posterior orientation of the Descemet endothelial complex (DEC) is one of the causes of failure of Descemet membrane endothelial keratoplasty (DMEK). We evaluated a new marking technique to avoid such a misorientation. Method. A new marking technique of the DEC was evaluated in patients requiring primary DMEK. A Braille-“R”-letter was applied dot by dot onto the stromal surface of the DEC after lifting it by injecting an air-bubble into the interface between the endothelial surface of the partially stripped graft. The positioning of the graft was intraoperatively controlled by an orientation of the Braille-“R”-letter. Laboratory tests were conducted to test the impact of the marking technique on endothelial cell count. Results. We included prospectively 37 eyes of 30 patients. Four eyes were phakic and 33 pseudophakic. Five grafts (14%) presented an undifferentiated rolling tendency in the anterior chamber, and evaluation of their positioning was possible due to orientation of the mark alone. In case of an upside-down orientation, grafts were flipped immediately. A correct orientation of the graft was achieved in all cases at the end of the surgery. The endothelial cell loss due to the mark was estimated to be less than 0.3%. At 3- and 6-month follow-ups, the mean best-corrected visual acuity was 0.21 ± 0.15 and 0.15 ± 0.11 logMAR, respectively, and endothelial cell density was 1661 ± 349 and 1618 ± 396 cells/mm2, respectively. Only one patient (3%) needed re-bubbling. Conclusions. To rely on the natural rolling tendency of the graft alone does not assure its correct positioning in all cases. Creation of the mark with 4 dots punctuated on the air-lifted stromal side of the DEC is a simple and endothelial cell saving marking method to ensure correct orientation of the graft during DMEK.

Ink Retention and Endothelial Cell Viability After the Application of an Orientation Stamp Over an Air Bubble During Descemet Membrane Endothelial Keratoplasty Graft Preparation

“…We have determined that the application of an orientation mark to the stromal surface of DMEK tissue supported by a small air bubble positioned at the edge of the 2 endothelial surfaces of the graft results in a single, solid stamp that is readily visible both 2 and 5 days after processing and furthermore, that this stamp remains visible after undergoing cross-country shipping conditions. This extends the findings of Wasielica-Poslednik et al, 13 who first reported that an orientation mark applied to DMEK tissue over an air bubble in the operating room immediately before graft insertion resulted in a stamp that was readily visible to the surgeon and could be used to verify correct orientation of the DMEK graft. In the United States, most DMEK tissue is prestripped and preloaded at an eye bank and then shipped to a surgery center for use, 22 not prepared at the time of surgery, making the retention of an orientation mark over several days and shipping conditions of critical importance.…”

“…[10][11][12] A modification to the orientation stamp technique was recently described by Wasielica-Poslednik et al 13 In this study, the Braille letter "R" was applied to the stromal surface of the Descemet-endothelial complex, whereas the complex was supported with an air bubble inserted between the endothelial surfaces of the partially stripped graft in the operating room immediately before surgery. 13 The authors did not examine endothelial cell loss (ECL) associated with tissue processing incorporating these steps; however, the 6month cell loss for the 37 grafts in the series was 35.3% 13 and comparable with other reported outcomes of DMEK. [14][15][16] In the United States, most DMEK grafts are prepared by an eye bank, several days before surgery.…”

Comparison of DMEK and DSAEK in Eyes With Endothelial Decompensation After Previous Penetrating Keratoplasty

“…The average number of previous ophthalmological surgeries of the respective eye in the DMEK group was 3.2 (62.4, range 1-9) compared with 5.8 (63.4, range [3][4][5][6][7][8][9][10][11][12][13][14] in the DSAEK group.…”

“…The Descemet endothelial complex for DMEK was prepared and marked preoperatively by the surgeons using the method described elsewhere. 14 DSAEK grafts were cut in the eye bank using the microkeratome AMADEUS II (Ziemer Ophthalmology GmbH, Emmendingen, Germany).…”

Single peripheral triangular mark ensuring correct graft orientation in DMEK

“…2017) or dots placed on the stromal side of the EDM (Wasielica‐Poslednik et al. 2019) could lead to additional tissue manipulation, and a marking pen containing alcohol could be toxic (Ide et al. 2008).…”