OCULUS Pentacam Interpretation Guide

141
19 Dependency of effective phacoemulsification
time on Pentacam
®
Nucleus Staging (PNS)
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.
In a previous study [44] we found that EPT increases with increasing PNS both in conventional and
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).

OCULUS Pentacam Specifications

General

Measurement Time	Less than 2 seconds
Corneal Coverage	Up to 12 mm
Software	Pentacam Software
Data Transfer	USB
Corneal Topography	Yes
Display	External monitor required
Measurement Principle	Scheimpflug imaging
Camera	Rotating Scheimpflug camera
Light Source	Blue LED
Pachymetry	Yes
Anterior Chamber Analysis	Yes
Imaging Principle	Scheimpflug imaging
Fixation	Internal
Power Supply	100-240 V, 50/60 Hz
Resolution	High resolution
Lens Density Measurement	Yes
Dimensions	Varies depending on model and configuration
Weight	Varies by model, check manufacturer specifications
Number of Images	25 or 50