Learning curve of two common Descemet membrane endothelial keratoplasty graft preparation techniques

To compare the learning curve of two Descemet membrane endothelial keratoplast (DMEK) graft preparation techniques.

Experimental study.

Twenty paired donor corneoscleral rims.

The corneas were randomized to DMEK peeling using the peripheral blunt dissection technique (n = 10) or the modified submerged cornea using backgrounds away (mSCUBA) technique (n = 10). Outcome measures included graft peeling time, surgeon's peeling difficulty grading (on a scale of 1 to 10, 1 being the easiest and 10 the hardest), number of tears, and percentage tissue loss.

Average graft peeling time using the peripheral blunt dissection technique and the mSCUBA technique was 15.75 ± 4.01 minutes and 8.43 ± 3.26 minutes, respectively (p < 0.0005). The first 3 grafts' average peeling time was longer than the last 7 grafts: 19.14 ± 2.40 versus 14.21 ± 3.50 minutes in the peripheral blunt dissection technique (p = 0.06) and 12.36 ± 3.76 versus 6.67 ± 0.49 minutes in the mSCUBA technique (p = 0.016). In the latter, there were significantly fewer radial tears compared to the former: 1.5 ± 1.0 and 3.1 ± 1.9, respectively (p = 0.049). No tissue loss was noted in the mSCUBA group compared to one (10%) in the peripheral blunt dissection group. The average difficulty grading for the mSCUBA was significantly lower than the peripheral blunt dissection technique: 3.3 ± 1.9 and 5.8 ± 1.6, respectively (p = 0.024).

Our study suggests a shorter learning curve with the mSCUBA technique for DMEK graft preparation, with shorter peeling time and fewer complications in comparison to the peripheral blunt dissection technique.