Transcript Ks after DSEK - ASCRS/ASOA 2009

John P Berdahl M.D.*
David R. Hardten M.D. , F.A.C.S.*
*No relevant financial disclosures
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
Methods
 Comparisons
Comparison of DSEK eye
(pre and post-op)
Comparison to contralateral eye
 Keratomety (Manual or Topo)
 Change in Keratomety
 Pachymetry
 Change in Pachymetry
 Axial length (if present)
 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
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.
Results
Average change from predicted refractive error was 1.3D more hyperopic
Pre and Post Operative
Average Keratometry
45
44.0
44
42.0
40.0
Pre-op K
43
43.33
4
-4
42.81
42
Average K
Change in refraction from predicted
(D)
Comparison of Pre- and Postop Keratometry in
Individuals
46.0
Average K (D)
Average K (D)
Average keratometry flattens by -0.52D (p<0.05)
41
y = -0.1044x + 1.3146
R² = 0.0085
2
flatter
steeper
0
-2
0
2
-2
38.0
0
5
10
15
Patient Number
20
40
Pre-op
Post-op
-4
Change in Keratomery (D)
No correlation between change in K’s from DSEK and change from predicted refraction
4
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
Conclusions
 Corneal flattening may contribute the hyperopic
shift commonly observed after DSEK.