Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK) is a revolutionary surgical procedure that allows replacement of the diseased endothelium in cases of endothelial corneal dystrophies and bullous keratopathy. In such cases, PKP can be avoided and a less invasive approach can be employed.
One of the main concerns when performing DSAEK is donor graft adherence in the immediate postoperative period. It has been reported that 15 to 30% of the donor grafts are not fully attached and may be dislocated or floating in the anterior chamber (AC) [3, 4]. Possible explanations for that could be presence of interface fluid or air, patient squeezing and eye rubbing, and problems with the preparation, handling, and insertion of lamellar donor tissue [6]. Additionally, the learning curve for the DSAEK technique, as it is a fairly new procedure, could account for graft detachments and dislocations.
Covert DJ et al [7] effectuated a combined procedure of phacoemulsification followed by DSAEK resulting in higher rates of graft detachment (3 out of 21 eyes) in respect to simple DSAEK procedures probably due to the need for further intraoperative manipulations.
Detachments or dislocations are usually treated with additional air injection into the AC or with graft exchange when adherence cannot be achieved.
In this case report we present a patient with displaced donor graft after DSAEK and associated peripheral corneal edema that resolved without any further intervention three months postoperatively.
It is assumed based on the patient's clinical outcome that even though the donor graft was displaced, the transplanted endothelial cells continued active pumping [7] of water and ions from the corneal stroma. Ultimately, stromal deturgescence and transparency [8] even in areas uncovered by the displaced donor graft were effectuated.
This phenomenon can be explained by presuming that the cornea is a structure that works as an integral. The functioning endothelial cells were sufficient enough to meet the needs of the cornea and to counteract pre-existing edema.
Other possible mechanisms that may have contributed to the eventual clearing of the peripheral corneal edema are endothelial cell migration to areas uncovered by the graft and/or dislocated endothelial cells function. Despite the clearing of the corneal edema, the edge of the donor graft being close to the photopic pupil margin would be expected to cause problems with visual quality such as night vision disturbances and increased higher order aberrations.
Similar cases of detached but not displaced grafts have been reported in the literature. Balachandran et al [9] described 2 cases of spontaneous corneal clearance after Descemet membrane endothelial keratoplasty (DMEK) suggesting endothelial transfer, migration, regeneration, or a combination thereof from either the donor or the recipient as possible explanations of the phenomenon. Dirisamer et al [10] analyzed the presence of different re- endothelialization patterns after DMEK such as massive endothelial migration or some form of cell signaling to draw donor endothelial cells toward the recipient posterior stroma ("homing").
In conclusion, displaced corneal graft after DSAEK can lead to transient corneal edema in areas uncovered by a displaced graft which can be resolved within a few months without the need of further intervention such as donor button replacement or repositioning.
