Transcript PresentinTORIC versus Limbal Relaxing Incisionsg

Comparison in Reduction of Preoperative
Astigmatism after Cataract Surgery with
Toric IOLs versus
Limbal Relaxing Incisions
Alexander Chop PhD MD
(no financial interests to disclose)
Dan Straka & Asmaneh Siavosh M4
(no financial interests to disclose)
William G. Martin MD, FACS
(consultant to Alcon and AMO)
The University of Toledo College of Medicine
Introduction
There are three main options for reducing
astigmatism at or around the time of
cataract surgery, namely performing one or
more limbal relaxing incisions (LRIs),
implanting an intraocular lens known as a
Toric IOL which corrects for astigmatism
and finally postoperative PRK. Here we
compare the short term results of the first
two methods at the three month
postoperative period.
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Disadvantages of LRIs
• Technique is less precise than a Toric IOL the cornea may undergo an over-correction
or under-correction.
• The cornea will heal over time, altering the
result.
• The depth, length and curvature of the
wound will vary both within each eye and
between eyes and patients, as well as
surgeons.
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Disadvantages of Toric IOls
• Cost - generally more expensive than LRIs.
• Concern over rotational stability of the lens
in the bag.
• Amount of correction available is not as
great as with LRIs and has larger steps
between lens powers compared to LRIs.
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Retrospective Study Design
• Chart review from 2006 -2008 comparing 32 eyes
of patients undergoing LRI at the time of cataract
surgery using the Alcon SN60WF IOL with 37 eyes
of patients undergoing implantation with the Alcon
AcrySof SN60T3/4/5 Toric IOL, matched for cataract
density, age and sex and treated using the Wallace
LRI nomogram and IOL Master.
• Consistency: all procedures performed by the same
surgeon (WGM) in the same ASC using the same
superior scleral tunnel approach with pre- and
postoperative measurements by the same
technicians
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Results for LRIs + Alcon
SN60WF IOL Implantation
• Residual postoperative astigmatism
measured at 3 months (N = 32) reflects
an improvement of 1.41 D cylinder (64%
reduction in astigmatism)
• LRI patient average preoperative cylinder
= 2.20 D (range 0.75 - 6.00)
• LRI patient average postoperative
cylinder = 0.79 D (range plano - 3.00)
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Results for Alcon SN60T3/4/5
Toric IOL Implantation
• Residual postoperative astigmatism
measured at 3 months (N = 37) reflects
an improvement of 2.25 D cylinder (77%
reduction in astigmatism)
• Toric IOL average preoperative cylinder =
2.92 D (range 1.50 - 4.75)
• Toric IOL average postoperative cylinder
= 0.67 D (range plano - 2.50)
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Conclusion
• Both methods are effective in reducing preoperative
astigmatism and both should be offered to patients.
• At the three month postoperative period, the Toric
IOL shows a slightly greater reduction in
preoperative astigmatism (77% compared to 64%)
but was not statistically significant. Average Toric
IOL patient had more preoperative astigmatism
than LRI patient, potentially biasing results.
• Longer term results of at least the three year
postoperative period must be measured.
• Prospective study is needed with patients matched
for equal preoperative astigmatism and controlling
all other variables.
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