Comparing The Unfolding Time And Tapping Rate Required Between ‘No Touch’ Endo-In Dmek And Standard Dmek

To establish if there is a difference in tapping rates and graft unfolding times when ‘No-touch’ Endo-In DMEK is compared with standard DMEK.

All surgeries were performed and recorded at the Cape Eye Hospital in Cape Town, South Africa. Each surgery was reviewed and the time required to unfold the graft completely was calculated as well as the amount of taps required to unfold the graft completely. The two groups were then compared with each other to see if there was a statistically significant difference.

Real time video (Zeiss) of 19 ‘no-touch’ DMEK surgeries were reviewed retrospectively and compared with 19 real time videos retrospectively when standard DMEK was performed. Tapping rates and graft unfolding times were calculated until the grafts were opened completely, after graft injection into the anterior chamber . A Brunner-Munzel test was used to compare the two groups with each other, after calculating the standard deviation and mean for each category. 

The mean tapping rate for ‘no-touch’ Endo-In DMEK was 10.6315 taps, ( SD=11.30983). The mean tapping rate for standard DMEK was 146.5789 taps, (SD=175.5431).  In this sample, ‘no-touch’ Endo-In DMEK required 92.75% fewer taps to unfold the graft.

The mean graft unfolding time for ‘no-touch’ Endo-In DMEK was 7.8947 seconds, (SD=12.3013). The mean graft unfolding time for standard DMEK was 140.1053 seconds (SD=143.9645). The Brunner-Munzel test confirmed a statistically significant reduction in graft unfolding time when ‘no-touch’ Endo-In DMEK was performed (p < 2e-16). In this sample, 'no-touch' Endo-In DMEK required 94.37% less time to completely unfold the graft.

The Brunner-Munzel test confirmed a statistically significant reduction in tapping rate and time to completely unfold the DMEK graft when ‘no-touch’ Endo-In DMEK was performed (p < 2e-16). ‘No touch’ Endo-In DMEK required less time to completely unfold the graft and less taps to completely unfold the graft than when standard DMEK was used, after graft injection into the anterior chamber. Furthermore, ‘no-touch’ Endo-In DMEK is a less variable and more predictable procedure when compared to standard DMEK. All grafts were correctly oriented. In our assessment ‘no-touch’ Endo-In DMEK requires less manipulation of the DMEK graft than when standard DMEK is used.