(PNS – pentacam nucleus staging) X LOCS III
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Transcript (PNS – pentacam nucleus staging) X LOCS III
Correlation between Preoperative cataract grading by
Scheimpflug imaging and phaco time and power US
in phacoemulsification.
Bruno Valbon; Ana Canedo; Leonardo Pimentel; Isaac Ramos; Ricardo Louzada; Renato Ambrósio Jr.
* Dr. Ambrosio is a consultant to Oculus and in the speaker bureau for Reichert, Alcon and Allergan
Purpose : To analyze the correlation between patient
nuclear score (PNS) by Scheimplufg imaging and
phaco time and power US in patients who had
uneventful clear cornea phacoemulsification
Valbon B; Canedo A; Pimentel L; Ramos Isaac, Louzada R. Ambrosio Jr R
INTRODUCTION
The current standard for grading cataracts is the Lens Opacification Classification System III (LOCS III).
This system is, however, potentially subjective and the results are open to interpretation. An objective and
reproducible method of cataract evaluation is not yet available.
Furthermore, there is no universal means by which to correlate the objective cataract evaluation with the amount
of energy needed to remove a cataract during phacoemulsification.
The efficiency of ultrasound (US) energy use in phacoemulsification systems is critical.
Lower levels of US power can limit endothelial cell damage; therefore, it makes sense to plan phaco surgery
with the lowest levels of US power needed based on cataract density.
Is common for surgeons to alter phaco settings intraoperatively according to the den- sity of the cataract.
It would be more efficient to set phaco variables preoperatively based on objective and reproducible cataract
density results.
Valbon B; Canedo A; Pimentel L; Ramos Isaac, Louzada R. Ambrosio Jr R
METHODS
Patients scheduled to have cataract surgery by the same surgeon (RA) had similar preoperative
evaluations, including Pentacam Scheimpflug assessment using the PNS.
Patients were excluded if preoperative examinations indicated a need for complex cataract
surgery that could lead to complications.
22 eyes from 22 patients who had uneventful clear cornea phacoemulsification and foldable IOL
implantation were included.
Phaco time and power US were performed after surgery each patient.
The Test Kolmorogov-Smirnov was used to evaluate normal distribuition.
The correlations were evaluated with Pearson rank correlation. A P value lower than 0,05 was
considered statistically significant.
PNS x Phaco Time and PNS x US power were correlations realized.
Valbon B; Canedo A; Pimentel L; Ramos Isaac, Louzada R. Ambrosio Jr R
METHODS
(PNS – pentacam nucleus staging)
Valbon B; Canedo A; Pimentel L; Ramos Isaac, Louzada R. Ambrosio Jr R
METHODS
(PNS – pentacam nucleus staging)
PNS 1
X
LOCS III
PNS 3
Valbon B; Canedo A; Pimentel L; Ramos Isaac, Louzada R. Ambrosio Jr R
Results :
22 eyes of 22 patients were studied.
Correlation between PNS x Phaco Time was p < 0,0050 and RP (Rank
- Pearson) 0,5757 (Graphic 1).
Correlation between PNS x Power US was p < 0,0029 e RP( Rank Pearson) de 0,6034 (Graphic 2).
Valbon B; Canedo A; Pimentel L; Ramos Isaac, Louzada R. Ambrosio Jr R
DISCUSSION
The ability to objectively and reproducibly assess pre-operative characteristics of the nuclear component
of a cataract to determine its grade would have value in preoperative surgical planning.
The most widely used cataract grading system, the LOCS III, is open to interpretation because
of its subjective nature; thus, surgeons have no analytical tool to link cataract grade and surgical
settings.
In this study, a Scheimplug imaging system was used to determine objective cataract grades, with the
phaco parameters adjusted preoperatively and to realize correlations between phaco time, power US and
PNS.
This present study found a statistically significant between PNS, phaco time and power US.
In conclusion, customizing phaco parameters based on an objective cataract grading may be a means to
improve phaco efficiency.
Valbon B; Canedo A; Pimentel L; Ramos Isaac, Louzada R. Ambrosio Jr R
Correlation between Preoperative cataract grading by Scheimpflug imaging and phaco time and power US in phacoemulsification
Bruno Valbon; Ana Canedo; Leonardo Pimentel; Isaac Ramos; Ricardo Louzada; Renato Ambrósio Jr.
[email protected]
Thank you !!
Valbon B; Canedo A; Pimentel L; Ramos Isaac, Louzada R. Ambrosio Jr R