Dependency Of Effective Phacoemulsification Time On Pentacam ® Nucleus Staging (Pns) By Mehdi Shajari Md, Wolfgang Mayer Md, Prof. Thomas Kohnen; Introduction - OCULUS Pentacam Interpretation Manual

19 Dependency of effective
phacoemulsification time on Pentacam
nucleus staging (PNS)
by Mehdi Shajari MD, Wolfgang Mayer MD,
Prof. Thomas Kohnen

19.1 Introduction

The Pentacam® HR Scheimpflug imaging system can be used for cataract grading with the Pentacam®
nucleus staging (PNS) classification. It evaluates the optical density of the lens by analyzing the
backward scatter. For reliable results it is critical to perform the examination when the eye is dilated.
The software automatically calculates the density of a central, 3-dimensional reference block, grading
it from 0 to 5.
During conventional cataract surgery phacoemulsification has to be performed. The effective
phacoemulsification time (EPT) shows how long the phacoemulsification time would have been
if 100% power had been used in continuous mode and is calculated by multiplying the total
phacoemulsification time by the average percentage of total power used.
[44]
In a previous study
femtosecond laser-assisted cataract surgery. Furthermore we found that EPT is significantly less in
femtosecond laser-assisted cataract surgery compared to conventional cataract surgery (p = 0.001).
we found that EPT increases with increasing PNS both in conventional and
19 Dependency of effective phacoemulsification
time on Pentacam ® Nucleus Staging (PNS)
®
141