OCT-Assisted DSAEK: Residual Fluid and Patient Outcomes
American Journal of Ophthalmology, December 2016
Hallahan et al. used intraoperative optical coherence tomography (iOCT) to measure graft-host interface fluid during Descemet stripping automated endothelial keratoplasty (DSAEK). Despite the advantages of DSAEK, there is risk for postoperative graft dislocation and failure, which may be a function of residual fluid at the graft-host interface. The authors validated iOCT for measurement of residual interface fluid during DSAEK and found that greater amounts of interface fluid correlate with early graft nonadherence.
In this study, known as PIONEER, 173 patients (178 eyes) who underwent DSAEK were evaluated prospectively. After each graft was positioned, adherence was facilitated by either manual pressurization of the anterior chamber or an active air infusion system. Serial iOCT images were obtained during DSAEK and were analyzed with an automated algorithm to quantify interface fluid. Patients were followed for up to 1 year postoperatively. Study endpoints included graft nonadherence or the need for reintervention.
Fluid measurements from final iOCT images (i.e., obtained immediately after the last surgical maneuver) included total fluid volume, largest volume in 1 fluid pocket, maximum fluid area, mean fluid thickness, and maximum fluid thickness. These measurements correlated positively with graft nonadherence in the first postoperative week. Both techniques for promoting graft adherence significantly decreased interface fluid, and reintervention rates were similar. Final iOCT images of the 21 grafts that exhibited partial nonadherence or complete dislocation during postoperative follow-up showed significant elevation of total fluid volume, largest volume in 1 fluid pocket, and maximum fluid area.
This study is the first to correlate iOCT measurements of residual graft-host interface fluid with graft nonadherence in the early postoperative period. The authors concluded that more fluid at completion of surgery is predictive of early graft nonadherence and, further, that iOCT can differentiate fluid dynamics during DSAEK.
The original article can be found here.