Jan-Fev - Sociedade Brasileira de Oftalmologia

Comparison of central corneal edema and visual recovery between liquefaction and conventional...
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Figure 1: Comparison of the best corrected visual acuity evolution between Aqualase ® and
conventional phacoemulsification (n=20)
devices were removed. During the postoperative time,
eye drops were prescribed, including the use of topic
fourth generation quinolones 4 times a day, for 7 days,
and steroids (dexamethasone 1%) 4 times a day, tapered
over a 30-day period. Intraoperative parameters settled
in the machine, for conventional phacoemulsification
were 70% linear ultrasonic power with 40% time on and
40cc/min aspiration rate with 500 mmHg vacuum and
for Aqualase were 70% linear liquefaction power with
40% time on and 40cc/min aspiration rate with 500
mmHg vacuum. The in the conventional
phacoemulsification were 49.12 ± 11.93 seconds and
Aqualase time were 65.51 ± 12.19 seconds. All number
and magnitude were listed and recorded at the end of
the surgery, the ultrasonic/liquefaction elapsed time,
mean power time for conventional phacoemulsification
and pulses magnitude for Aqualase.
Postoperative corneal edema was not clinically
significant at biomicroscopic examination, no descemet’s
folds or loss of tranparency was noted. Measurement of
the central edema was done using corneal optical
pachymetry (Orbscan II ® ) on the 1 st , 3 rd , 7 th
and 10 th
postoperative days. This is diagnostic system that scans
the surface of the eye and acquires over 9000 data points
in 1.5 seconds to map the entire corneal surface (11mm),
analyzing the elevation and the curvature measurements
on both the anterior and posterior surfaces of the cornea.
Some trials have shown excellent correlation, 4 weeks
afer surgery, between this system and ultrasonic measures
and good repeatability (3-6) .
Data were analyzed using the Statistical Program
Statistica, version 5.1. Statistical analysis of the results
were performed by Mann-Whitney testing for analysis
of variance. A p value less than 0.05 was considered
statistically significant.
RESULTS
None of the 20 patients submitted to surgery was
lost during the postoperative follow-up or excluded from
the analysis. On the first postoperative day, the mean
visual acuity was 0.031 logMAR in the Aqualase ® group
and 0.043 logMAR in the conventional surgery group
(approximately 20/20 on the Snellen table, for both
groups). No statistical difference was detected in the
assessment of visual acuity in the postoperative period;
results are shown on Figure 1.
The surgery ultrasonic/liquefaction elapsed time
in the conventional phacoemulsification were 49.12 ±
11.93 seconds and Aqualase time were 65.51 ± 12.19
seconds.
All number and magnitude were listed and
recorded at the end of the surgery for conventional
phacoemulsification (mean 11 ± 1.9; mean power time
29,33 ± 4.0 seconds) and for Aqualase (Mean 12 ± 2.12;
pulses 3900 ± 1162; magnitude 68.23 ± 18.99).
Mean pre and postoperative central pachymetric
values for both groups are shown on Table 1. The central
corneal thickness average in both groups achieved
543.53 ± 32.16 microns before surgery and 550.62 ± 34.82
microns after surgery. There was no statistically
significant difference between Aqualase ®
and
conventional ultrasonic phacoemulsification in the central
pachymetry exam.
DISCUSSION
In this study, we have compared the central corneal
edema of patients submitted to cataract surgery
performed with conventional phacoemulsification in one
eye and with liquefaction, by Aqualase ® , in the fellow
Rev Bras Oftalmol. 2009; 68 (1): 7-12