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24. Kongress der DGII 2010
Abstracts DGII 2010
XII.
Wissenschaftliche
Sitzung: Phakotechniken
R93
Surgical options with narrow pupil and floppy
iris syndrome
Malyugin B
S. N. Fyodorov State Institution, Moskau (Russland)
The main reasons for encountering small pupils during cataract surgery
are well established. They include cases with pseudoexfoliation
syndrome, uveitis, posterior synechiae. Campbell have described the
intraoperative floppy-iris syndrome (IFIS) associated with systemic
administration of the a-1A antagonist tamsulosin (Flomax). The
intraoperative diagnostic triad of this symptom is fluttering and billowing
of the iris stroma, a tendency to iris prolapse through the
main and/or sideport incisions, and progressive constriction of the
pupil during surgery. Unfortunately, current pharmacological approaches
for managing a small pupil during cataract surgery have
limitations. Patients whose pupils respond poorly to the pharmacological
protocols present significant challenges. The most significant
problems for the surgeon are decreased visualization, iris trauma
due to incarceration into the wound, iris chafing, pupillary margin
damage by the phaco needle and others. All of these problems
compromise the surgery and increase the risk for complications.
There is
no general recommendation or solution to the small pupil problem
because the strategies for pupil enlargement greatly depend on surgeon
skill and preferences, as well as on intraoperative situation.
Most surgeons decide to dilate the pupil mechanically at the time
of the surgery if pharmacological agents fail. There are four main
mechanical dilation methods: synechiolysis, mechanical stretching,
cutting of the iris tissue and iris retraction. Most of the surgical
maneuvers for enlarging the pupil and preventing its intraoperative
constriction are not safe enough. They can lead to an increased risk
of iris sphincter tear, bleeding, iris damage, posterior capsule tears
and loss of the vitreous body. But not all patients require pupil
dilation protocols with the mechanical devices. If the iris tissue is
rigid and the diameter of the pupil is about 4.0 mm to 4.5 mm, an
experienced surgeon, especially when using different modifications
of phaco-chop technique, can effectively remove cataract and avoid
significant trauma of the anterior segment tissues. Conversely, if the
iris tissue is flaccid and atonic, even if the pupil is reasonably wide,
such as with IFIS, there is a significant risk of complications. The
postoperative complications can include an atonic pupil of irregular
shape with poor cosmetic result and photophobia. One of the newest
devices to enlarge the small pupil during phacoemulsification is the
Malyugin Ring utilizing the scroll principle of catching the papillary
margin (Figure 1).
Malyugin Ring System consisting of a sterile single-use inserter and
holder. The dark blue Ring is located inside the holder and can be
visualized through its upper portion. It can be used with conventional
SICS (Small Incision Cataract Surgery) as well as MICS (Microincision
Cataract Surgery). The newest version – the 7.0-mm Malyugin Ring
produced by MST provides a larger pupil diameter compared to the
conventional 6.25-mm ring. 7.0 Ring handles IFIS cases
more easily. When the iris is very flaccid but the pupil is wide, the
6.25 mm Ring can be dislocated at one or two scrolls and would
need to be repositioned. This does not happen with the larger-size
Ring.
Advantages of the Malyugin Ring: Adequate transpupillary
access to the lens is essential for the success of phaco procedures.
We believe that our irisretraction technique with the Malyugin Ring
System has at least six distinct advantages:
1. The single-use ring is as effective as other conventional iris
hooks; however, compared with other commonly used iris retractors,
it is friendlier to the eye due to its well distributed
stretching, gentle holding of delicate iris tissue and the easier
and less traumatic implantation. It has no sharp or pointed
endings that can damage the eye.
2. An equidistant positioning of the loops holds the iris tissue,
ensuring correct position of the iris and preventing the effects of an
overstretched pupil that are often observed in the incorrect
positioning of iris hooks.
3. The device applies pressure to the sphincter muscle over an area
that is wider than with iris hooks. It is particularly useful in
patients for whom cutting or tearing of the iris tissue should be
avoided, especially in the presence of rubeosis, chronic anterior
uveitis or systemic coagulopathy. The iris rim is safely fixed in
the Ring’s loops and there is no risk of iris aspiration during
phacoemulsification.
4. Additional incisions are not required. This instrument is inserted
through the one main incision, thus reducing surgical trauma
and minimizing the risk of contamination and postoperative
inflammatory reaction. In the technique, when the square pupil is
formed by the conventional iris retractors, the iris can prolapse
through the wound. This is particularly true in patients with
relatively wide paracenteses and atonic and atrophic irises that
seem particularly floppy.
5. Sufficient room is available for nucleus fragmentation and
removal. The device configuration allows a surgeon to work in the
deep lens layers below the iris plane and the squareshaped pupil
formed by the ring. This provides enough space for grooving and
cutting the nucleus and increases peripheral visualization during
the chopping phase.
6. The ring is inserted and removed from the eye with an inserter,
reducing the risks of contamination and disturbance of the incision’s
architecture and wound integrity.
Summary:
Different techniques of nucleus disassembly in small-incision
cataract surgery require a wide and unobstructed view of the
anterior portion of the lens, as well as of the instruments inserted
into the anterior chamber. The other important factor is sufficient
manipulability of the instruments, which is critical for the successful
completion of surgery. A pupil that fails to dilate makes cataract
removal more difficult. The Malyugin Ring adequately dilates the
pupil and prevents iris sphincter damage. The ease of inserting and
removing the device expands the pupil, protects the iris sphincter
during surgery, and allows the pupil to return to its normal shape,
size and function after the operation. Careful intraoperative
manipulation and insertion of the Ring, with liberal use of an ophthalmic
viscoelastic device, helps to prevent complications. Most of our post-op
patients had pupils almost indistinguishable in appearance than
before surgery and functional activity was preserved. This is among
the most effective methods to increase the size of even very rigid
small pupils during phacoemulsification abnormalities in pupil size
and function.
Erschienen in:
Klin Monatsbl Augenheilkd 2010; 227: Suppl. 1, S1–S24
Georg Thieme Verlag KG Stuttgart · New York · ISSN 1431-634X
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