1. John P Berdahl M.D.* David R. Hardten M.D., F.A.C.S.* *No relevant financial disclosures

2. Background Descemet’s Stripping Endothelial Keratoplasty (DSEK) is known to cause a hyperopic shift. The hyperopic shift has been attributed to the divergent refractive property of the DSEK lenticule itself. Other factors such as keratometry and axial length could also contribute. Purpose To evaluate if keratometry changes are caused by DSEK and if changes correlate with induced refractive error

3. Methods Comparison to contralateral eye Keratomety (Manual or Topo) Pachymetry Axial length (if present) Comparisons Comparison of DSEK eye (pre and post-op) Change in Keratomety Change in Pachymetry Change in Visual acuity Change in refraction from prediction* *Predicted post-op refraction was based on IOL calculations in patients with combined cataract surgery. *Predicted post-op refraction was identical to pre-op refraction in patients undergoing DSEK only

4. Results Average age - 60 10 Males, 10 Females Average f/u time 287 days No significant change in axial length (only measured in 2 patients) No significant difference in pre-op or post-op Keratometry was observed when comparing DSEK eye to contralateral eye.

5. Results No correlation between change in K’s from DSEK and change from predicted refraction steeper flatter Average change from predicted refractive error was 1.3D more hyperopic Average keratometry flattens by -0.52D (p<0.05) Pre-opPost-op

6. Summary A hyperopic shift of 1.3D is created by DSEK Average K’s flatten by 0.5D after DSEK (p<0.5) Flattening of keratometry was not statistically significantly correlated with the amount of induced hyperopia. However, a trend was observed since most eyes become flatter and more hyperopic. Pre-op Average K 43.5D POM #4 Average K 42.12D POM #11 Average K 42.31D

7. Conclusions Corneal flattening may contribute the hyperopic shift commonly observed after DSEK.