Impact of graft thickness on visual acuity after Descemet's stripping endothelial keratoplasty

Objective To evaluate the relationship, over time, between central graft thickness and visual acuity following Descemet's stripping endothelial keratoplasty (DSEK). Methods A retrospective analysis of 70 consecutive cases of DSEK. All donor lenticules were dissected manually. Serial postoperative measurements of central graft and total corneal thicknesses were made using anterior segment optical coherence tomography. Visual acuity, refraction and patient demographics were collected from case notes. The correlation between central graft thickness and visual acuity at serial time points was calculated. Results The median age at surgery was 75 years (lower quartile (LQ) 66, upper quartile (UQ) 83, range 36-90 years). Nineteen eyes were excluded from statistical analysis, leaving 51 eyes of 46 patients remaining. Last follow-up occurred a median of 12 months postoperatively (LQ 6, UQ 23, range 4-38 months). The median preoperative visual acuity was 0.71 logarithm of the minimum angle of resolution (logMAR), improving to 0.34 logMAR postoperatively (p<0.001, n=43). Median graft thickness decreased from 209 μm at day 1 to 142 μm at last follow-up (p<0.001). No statistically significant correlation was found between central total corneal thickness and visual acuity at any time point. Except for a single time point, no statistically significant correlation was found between central graft thickness and visual acuity. Conclusion There is no clear association between central graft, or total corneal, thickness and visual acuity following DSEK.