Value of Increase in Central Corneal Thickness as Indicator of Perioperative Corneal Endothelial Cel

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Value of Increase in Central Corneal Thickness as
Indicator of Perioperative Corneal Endothelial
Cell Damage in Phacoemulsification

• Charith Fonseka
• Ayeshmantha Peries

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Introduction

• Use of OVDs refinement of technology and
  techniques of phacoemulsification have
  tremendously improved the outcome of cataract
  removal
• Experienced surgeons rarely see gross corneal
  edema even with difficult cataracts though sub
  clinical evidence of increase in corneal
  thickness could be present
• Central corneal thickness (CCT) can be measured
  easily with ultrasonic pachymetry
• CCT has been evaluated and used in previous
  studies as an indicator of perioperative corneal
  endothelial cell loss

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Purpose of study

• To determine if the transient increase in the CCT
  after phacoemulsification is a valid predictor of
  corneal endothelial loss
• To determine what other factors play a role in
  increase in CCT

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Methods

• 67 consecutive patients with brown or black
  cataracts (age related) scheduled for surgery
  were included
• Parameters determined
• Age, Pre op CCT, Endothelial counts, Intraocular
  pressure (IOP)
• Post op CCT ( 2 24 hrs), Endothelial counts (
  1 week 1 month), IOP ( 2 24 hrs)

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Methods

• Mydriasis Tropicamide/phenylephrine
• Anesthesia Xylocaine jelly/intracameral
• Surgery Single surgeon,2.6 mm superior
  incision,Viscoat, Alcon Infinity system, Acrysof
  single piece IOL
• Cumulative dissipated energy (CDE), irrigation
  fluid volume, needle time

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Results
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Results Corneal endothelial evaluation
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Results correlations with change in CCT
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Results correlations with change in CCT
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Discussion

• Increase in CCT at 24 hours was very strongly
  correlated with endothelial cell loss as well as
  reduction in hexagonality
• It also had a strong correlation with volume of
  fluid used and the total needle time ( time
  insertion of phaco needle to removal)
• It showed little correlation with total expended
  energy or with intraocular pressure variations

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Conclusions

• The fact that endothelial cell loss occurs during
  phacoemulsification is well established. However
  excellent OVDs with new technology and techniques
  cell loss can be reduced to very low levels (5.5
  mean) even for very hard cataracts.
• This study indicates that volume of irrigation
  fluid used is proportional to cell damage.
  However the finding that procedure time (needle
  time) is correlated while the CDE is not
  indicates that mechanical damage from instrument
  and nuclear fragments (chatter) is more important
  than the total ultrasound energy expended.