Essential qualifications of reagents for visualization of vitreous body prolapsed in the anterior chamber after posterior capsule rupture.

1
Essential qualifications of reagents for
visualization of vitreous body prolapsed in the
anterior chamber after posterior capsule rupture.
Yuichi Kaji, M.D., Ph.D., Tetsuro Oshika,
M.D., Ph.D. Department of
Ophthalmology Tsukuba University Institute
of Clinical Medicine
Financial Interest The authors have no
financial interest in the subject matter of this
poster. Disclosure of Unapproved/Off-Label Use
The use of cholesterol and estriol for ocular
surgery is off-label. The use of 11-deoxycortisol
for ocular surgery is not approved by the FDA,
however, has been approved by the ethical
committee of Tsukuba University Hospital.
2
Introduction
Posterior capsule rupture with subsequent
vitreous loss is one of the most common
complications of cataract surgery.1,2 To minimize
the post-operative complications after posterior
capsule rupture, complete removal of prolapsed
vitreous body in the anterior chamber is
necessary.1,2 However, direct recognition of the
vitreous body under surgical microscope is
difficult, especially when the anterior chamber
is filled with lens fragments and viscoelastic
agents. To visualize the vitreous body during
pars plana vitrectomy, an injection of a
suspension of triamcinolone acetonide has been
used.3 Triamicinolone acetonide can be used to
visualize the vitreous body in the anterior
chamber after posterior capsule rupture.4
However, triamcinolone acetonide left in the eye
might be the cause of complications including
ocular hypertension. In the present study, we
compared various chemical reagents including
triamcinolone acetonide for the safety and
efficacy of visualization of vitreous body.
1. Chan FM, et al. Short-term outcomes in eyes
with posterior capsule rupture during cataract
surgery. J Cataract Refract Surg 29 537-541,
2003. 2. Gimbel HV, et al. Intraoperative
management of posterior capsule tears in
phacoemulsification and intraocular lens
implantation. Ophthalmology 108 2186-2189,
2001. 3. Peyman GA, et al. Triamcinolone
acetonide as an aid to visualization of the
vitreous and the posterior hyaloid during pars
plana vitrectomy. Retina 20 554-555, 2000. 4.
Burk SE, et al. Visualizing vitreous using
Kenalog suspension. J Cataract Refract Surg 29
645-651, 2003.
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Materials and Methods 0
0-0 Preparation of the substances suspensions
We compared the following 4 chemical reagents
for the safety and efficacy of visualization of
vitreous body in the anterior chamber using
animal models. In addition, the suspension of the
following reagents in balanced salt solution
(BSS) were prepared.
Triamcinolone Acetonide (Bristol-Myers, NY)
Cholesterol (Sigma, St. Louis, MO)
Estriol (Sigma, St. Louis, MO)
11-Deoxycortisol (Sigma, St. Louis, MO)
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Materials and Methods 1
 1-1 Animal Model of Posterior Capsule
Rupture Forty porcine eyes were purchased from
a slaughterhouse. After making a corneoscleral
wound and continuous curvilinear capsulorhexis,
the lens was aspirated using a phaco machine.
Then the posterior capsule was aspirated and torn
off using an irrigation/aspiration tip, so that
the vitreous body would prolapse into the
anterior chamber. Suspensions of 10mg/ml of
triamcinolone acetonide, cholesterol, estriol and
11-deoxycortisol in BSS were prepared. After
intentionally rupturing the posterior capsule of
the porcine eye, 0.5 ml of one of the suspensions
was injected through the corneoscleral wound. An
anterior vitrectomy system was utilized to remove
the prolapsed vitreous body. After the gentle
irrigation and aspiration, the non-adherent
particles were removed from the anterior chamber.
Then, the vitreous body entrapping the white
granules of the respective substance was removed.
Ten porcine eyes were used for each reagent.
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Materials and Methods 2
Toxicity of the reagents injected in the anterior
chamber. 2-1 Slit-Lamp Examination
Suspensions of 5 mg/0.1ml of triamcinolone
acetonide, cholesterol, estriol and
11-deoxycortisol in BSS were injected in the
anterior chamber of New Zealand white raibbits.
As controls, same volume of the BSS alone was
injected into the left eye. No other surgical
procedure was performed. 2-2 Intraocular
Pressure In the eyes receiving injections in
the anterior chamber, biomicroscopic examinations
were given and intraocular pressure measurements
taken using a pneumatic tonometer (MENTOR?, model
30 classic, Norwell, MA) before and 12 hours, 1,
2, 3, 7, 14 and 28 days after the injection.
2-3 Corneal Endothelial Density The corneal
endothelial cell density was measured using a
contact specular microscope (KONAN medical, type
class I, Hyogo, Japan) before and 28 days after
the injection. 2-4 Histology
Hematoxylin-Eosin staining of the corneas at 28
days after injection of the reagents into the
anterior chamber was prepared.
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Results 1
All the reagents were useful in visualization of
vitreous body prolapsed in the anterior chamber
after posterior capsule rupture.
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Results 2-1
Cholesterol induced severe corneal edema and
injection. In contrast, the other reagents
disappeared from the anterior chamber within a
day without any significant complications.
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Results 2-2
Cholesterol Triamcinolone Acetonide Estriol 11-De
xycortisol
Intraocular Pressure (mmHg)
0 1 2 3 7
14 28 days
Cholesterol injected into the anterior chamber
induced significant increase in the intraocular
pressure. In contrast, the other reagents
injected in the anterior chamber had no
significant effect on the intraocular pressure.
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Results 2-3
Corneal Endothelial Cell Density (/mm2)
uncountable
before
before
before
before
28 days
28 days
28 days
Triamcinolone Acetonide
Cholesterol
Estriol
11-Deoxycortisol
Triamcinolone acetonide, estriol, and
11-deoxycortisol injected into the anterior
chamber had no significant effect on the corneal
endothelial cell density. In cotrast, corneal
endothelial cell density could not evaluated
because of severe corneal edema after injection
of cholesterol.
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Results 2-4
Triamcinolone Acetonide
Cholesterol
Estriol
11-Deoxycortisol
Keratic precipitate containing macrophages,
neutrophils and lymphocytes with
neovascularization.
Triamcinolone acetonide, estriol, and
11-deoxycortisol injected into the anterior
chamber had no significant effect on the corneal
structure. In cotrast, cholesterol induced loss
of corneal endothelial cells, corneal stromal
edema, severe infiltration of inflammatory cells
in the anterior chamber.
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Discussion
Safety IOP Corneal
Endothelium Histology
Visualization of vitreous body.
Triamcinolone Acetonide Estriol Cholesterol 11
-Deoxycortisol
Good Good Good Good
? ? ? ?
? ? ? ?
no changes
no changes
Severe Toxicities
no changes
All the four reagents were effective in
visualization of vitreous body in the anterior
chamber after posterior capsule rupture. However,
cholesterol injected into the anterior chamber
had severe toxicities. In contrast, triamcinolone
acetonide, estriol, and 11-deoxycortisol had no
significant toxicities. For these reasons,
estriol and 11-deoxycortisol in addition to
triamicinolone acetonide could be used to
visualize the vitreous body after posterior
capsule rupture.
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Summary
Triamcinolone Acetonide (Bristol-Myers, NY)
Cholesterol (Sigma, St. Louis, MO)
Estriol (Sigma, St. Louis, MO)
11-Deoxycortisol (Sigma, St. Louis, MO)
Cholesterol skeleton is necessary for an
adherence to the vitreous body. All the four
reagents have hydrophobic modifications. However,
there is only one hydrophilic modifications in
cholesterol. This is the reason why cholesterol
injected into the anterior chamber tends to
remain and induce ocular hypertension. In this
way, molecules with cholesterol skeleton and
several hydrophilic modifications are thought to
be the essential qualifications of reagents for
visualization of vitreous body without any
complications. These are the molecular-based
reasons why triamcinolone acetonide is effective
in visualization of vitreous body in the
anterior chamber after posterior capsule rupture.