Effects of graft thickness and asymmetry on visual gain and aberrations after descemet stripping automated endothelial keratoplasty.

ABSTRACT

IMPORTANCE Understanding the contribution of graft thickness and asymmetry to visual gain and posterior corneal (PC) higher-order aberrations (HOAs) may assist optimizing visual outcomes after Descemet stripping automated endothelial keratoplasty (DSAEK). OBJECTIVE: To investigate the effects of graft thickness and asymmetry on visual gain and aberrations after DSAEK. DESIGN: Retrospective analysis of an interventional case series of eyes undergoing DSAEK. Visual gain was defined as the difference between preoperative and 6-month postoperative best-corrected visual acuity in logMAR equivalents. Graft thickness was measured by anterior-segment optical coherence tomography. Corneal topography and HOAs were measured by Scheimpflug imaging. Raw posterior corneal (PC) elevation data were exported and fitted against a best-fitted sphere, providing a measure of donor lenticule asymmetry. Correlation analysis was performed among visual gain, graft thickness, graft asymmetry, and PC HOAs. SETTING: University Eye Clinic Maastricht. PARTICIPANTS: Seventy-nine eyes with corneal endothelial dysfunction. EXPOSURE All patients underwent DSAEK [corrected]. MAIN OUTCOMES AND MEASURES: Visual gain, graft thickness, graft asymmetry, and PC HOAs. RESULTS: Mean best-corrected visual acuity improved from 0.63 logMAR equivalents preoperatively to 0.25 logMAR equivalents postoperatively (P < .001). Mean (SD) graft thickness of the series was 97 (25) (range, 39-145) µm. After excluding patients with vision-limiting comorbidities, visual gain significantly correlated with graft thickness (r = -0.35 [P = .02]). This correlation was strongest in patients with pseudophakic bullous keratopathy (r = -0.62 [P = .01]). Graft thickness significantly correlated with graft asymmetry in the 4- and 6-mm zones (r = 0.32 [P = .007] and r = 0.32 [P = .006], respectively), which in turn correlated with all but spherical PC HOAs. CONCLUSIONS AND RELEVANCE After DSAEK, visual gain shows a significant correlation with graft thickness in patients without vision-limiting comorbidities. This relationship is strongest in patients with pseudophakic bullous keratopathy. Graft thickness also correlates with graft asymmetry, which in turn correlates with all but spherical PC HOAs. These findings may assist surgeons in choosing DSAEK graft thickness and shape, particularly in eyes without vision-limiting comorbidities. Further randomized trials are needed to investigate the relationship between graft thickness and visual gain after DSAEK.