Comparison of Endothelial Keratoplasty (EK) Visual Outcomes with OCT Derived Corneal Thickness Measurements

1
Comparison of Endothelial Keratoplasty (EK)
Visual Outcomes with OCT Derived Corneal
Thickness Measurements

• Authors
• Abraham K. Sleem, MD
• Robert L. Schultze, MD
• Robert A. Eden, MD
• William Yang, MD
• Nadia Haqqie, BS

No Financial Interest in Study Material
2
Introduction

• The advent of Descemets Stripping with Automated
  Endothelial Keratoplasty (DSAEK) has changed the
  current approach to the treatment of endothelial
  diseases. The advantages of this procedure
  include shorter recovery time, less chance of
  sight-threatening complications, improved
  structural integrity of the cornea, and less
  irregular astigmatism compared to penetrating
  keratoplasty. While recent models and studies
  attempt to predict refractive outcomes based on
  donor tissue properties, this study investigates
  the relationship of the host and donor thickness
  related to best corrected visual acuity outcome.

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Purpose

• To determine the impact of pre-operative corneal
  thickness, as well as, post-operative donor,
  recipient, and overall corneal thickness on EK
  visual outcomes.

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Methods

• 47 eyes without visually significant retinal or
  optic nerve pathology underwent DSAEK by one
  surgeon (RLS).
• Pre-operative corneal pachymetry was measured by
  ultrasound.
• Post-operative recipient, donor and overall
  corneal thickness were determined utilizing the
  Visante OCT at one year.

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Methods

• Mean BSCVA of two groups stratified by donor
  thickness was compared using the student t-test.
• Post-operative BSCVA was also correlated with
  each measured thickness utilizing regression
  analysis.

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Surgical Technique

• DSAEK donor buttons prepared with 300 head on
  Moria ALTK system
• All Donors punched to 8mm
• Donor buttons inserted through 5 mm wound
• Cornea massage and venting performed
• Air bubble maintained for one hour then burped

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Results Data Collected
Parameter Average
Pre-Op Pachymetry 709.982.9µm
Post-Op BSCVA 20/35
Post-Op Recipient Bed Thickness 517.644.6µm
Post-Op Donor Thickness 162.738.9µm
Post-Op Total Thickness 680.363.4µm
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Results Statistical Analysis

• No correlation between pre-operative pachymetry
  and BSCVA (pgt0.05)
• No correlation between host recipient bed
  thickness and BSCVA (pgt0.05)
• The average post-operative BSCVA was 20/33 and
  20/36 for eyes with donor thickness lt162µm and
  162µm, respectively (plt0.04).
• No linear correlation between donor thickness and
  BSCVA (pgt0.05)

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ResultsBSCVA vs Donor Thickness
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Results Regression AnalysisNo Linear
Correlation between BSCVA and Donor Thickness
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Conclusions

• Although the group of eyes that received thinner
  donors (lt162µm) demonstrated statistically
  significant better post-operative vision on
  average, the difference was very small.
• No linear relationship between BSCVA and donor
  thickness was demonstrated with regression
  analysis.

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Discussion

• No clear linear relationship between
  post-operative BSCVA and donor thickness was
  demonstrated, however the group of eyes with the
  thinner grafts showed only slightly better
  vision.
• This may suggest that techniques that involve
  thinner grafts (ex. DMEK) may not necessarily
  result in better BSCVA.