Continuous External Pressure Technique For Descemet Membrane Endothelial Keratoplasty In Vitrectomized Eyes: The "Don't Let Go" Technique

Descemet membrane endothelial keratoplasty (DMEK) in vitrectomized eyes presents a formidable surgical challenge, as the compromised counter-pressure of the iris-lens diaphragm impedes proper shallowing of the chamber, rendering the unfolding and centration of the DMEK graft challenging. To address this challenge, surgeons often pivot to descement's stripping automated endothelial keratoplasty. The superior visual outcomes associated with DMEK, fast rehabilitation and low rejection risk, prompted exploration of tailored DMEK techniques after vitrectomy. This study describes a novel technique, which consists of continuous application of external pressure on the corneal surface while unfolding, centring and lifting the graft by gas.

Surgeries were performed by a single surgeon in the Rabin medical center, a tertiary hospital in Israel. 

Eight vitrectomized eyes with bullous keratopathy in patients averaging 68±13 years of age underwent Descemet membrane endothelial keratoplasty (DMEK) utilizing a novel continuous pressure technique. This technique involves maintaining consistent pressure on the corneal surface throughout the surgery with one hand, thereby keeping the anterior chamber shallow and preventing it from reforming, while graft unfolding, centration, and lifting it with the other hand. A detailed explanation of the technique will be provided. Outcomes were evaluated for each eye both before and 12 months after surgery. Statistical analysis was conducted using a Student's t-test.

All corneas cleared up well following surgery and remained clear for the twelve-month follow-up duration. The implementation of the continuous pressure technique allowed proper unfolding and centration of DMEK grafts in all of these challenging cases with minimal maneuvers to the grafts. Best corrected visual acuity following surgery improved significantly from an average of logMAR 1.05 to logMAR 0.37 (P-value 0.003) with no intra- or post-operative complications.

The application of continuous external pressure on the cornea (A.K.A the "Don't let go" technique) for DMEK in vitrectomized eyes is relatively easy to perform and was proven effective. The technique requires no additional instrumentation as Pars-plana infusion, synthetic diaphragm insertion to the chamber or direct contact with the graft as suggested by other authors for DMEK in vitrectomized eyes.