GRAFT SIZE AND REFRACTIVE OUTCOMES IN COMBINED DESCEMET MEMBRANE ENDOTHELIAL KERATOPLASTY TRIPLE PROCEDURE

To determine whether donor graft diameter is associated with a change in post-operative refractive shift in patients undergoing combined Descemet membrane endothelial keratoplasty (DMEK) triple procedure .

Single tertiary cornea center in British Columbia, Canada, associated with the Department of Ophthalmology at the University of British Columbia.

In this retrospective study, 49 eyes from 35 patients with Fuch’s endothelial dystrophy and cataract underwent combined DMEK triple procedure between 2018 and 2024. Post-operative spherical equivalent (SE) at 3 months was compared with the chosen pre-operative refractive target. Donor graft diameters ranging from 6.0 to 9.0 millimeters were recorded and correlated with the difference between the post-operative SE and biometry predicted SE using Pearson’s coefficient. Corneal curvature and pachymetry was collected to identify other factors associated with post-operative refractive outcome.

The average hyperopic shift post-DMEK triple procedure was +0.61D and tended to increase with increasing graft diameters, however the magnitude of shift was minimal (+0.069D/1.0mm increase) and was not statistically significant (r=0.037, p=0.798). There was a significant negative correlation between post-operative hyperopic shift and steep K (r = -0.440, p = 0.002).

Cornea surgeons may use variable DMEK graft diameters depending on extent of endothelial disease. We show that varying graft diameter does not impart an additional significant refractive shift. Other factors such as change in corneal curvature after endothelial keratoplasty may contribute more to hyperopic outcomes following DMEK.