Post on 19-Jan-2016
description
Topographic and Axial Length Changes after Descemet’s Stripping Endothelial
Keratoplasty: The effect on refractive error
John P Berdahl M.D.* David R. Hardten M.D. , F.A.C.S.*
*No relevant financial disclosures
BackgroundDescemet’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.
PurposeTo evaluate if keratometry changes are caused
by DSEK and if changes correlate with induced refractive error
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
ResultsAverage age - 6010 Males, 10 FemalesAverage f/u time 287 daysNo 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
-4 -2 0 2 4
-4
-2
0
2
4
f(x) = − 0.104403156653 x + 1.314613221897R² = 0.00849598707103993
Average K
Change in Keratomery (D)
Chan
ge in
refr
actio
n fr
om p
redi
cted
(D)
No correlation between change in K’s from DSEK and change from predicted refraction
steeperflatter
Average change from predicted refractive error was 1.3D more hyperopic
Average keratometry flattens by -0.52D (p<0.05)
0 5 10 15 2038.0
40.0
42.0
44.0
46.0
Comparison of Pre- and Post-op Keratometry in
Individuals
Pre-op KPost-op K
Patient Number
Avera
ge K
(D
)
Series140
41
42
43
44
45
43.3342.81
Pre and Post Operative Average Keratometry
Avera
ge K
(D
)
Pre-op
Post-op
SummaryA hyperopic shift of 1.3D is created by DSEKAverage 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-opAverage K 43.5D
POM #4Average K 42.12D
POM #11Average K 42.31D
ConclusionsCorneal flattening may contribute the
hyperopic shift commonly observed after DSEK.