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Step by Step Iris Clip
Dr Rahul AchlerkarDr Vijay Shetty
HISTORYItalian scientist Tadini in mid 18th century first considered
intraocular lens implantation.
In 1895, Casamata implanted glass IOL which sank
posteriorly.
English ophthalmologist Sir Nicholas Harold Lloyd Ridley
is credited for first successful IOL implantation on November
29th 1949, at St. Thomas’ hospital in London.
Sir Harold Ridley (1906-2001)
EVOLUTION AND DEVELOPMENT
Generation-I (1949-1954)
Biconvex PMMA PCIOL
Implanted behind iris after ECCE
Diameter – 8.32 mm; Power – 24 D
Complications:• Inferior decentration
• Posterior dislocation
• Inflammation
• Secondary glaucoma
Generation-II (1952-1962)
Early Anterior Chamber IOLs
Fixation of lens in angle recess
Advantages: Less decenteration
Decreased reaction
Complications:• Corneal decompensation
• Pseudophakic Bullous keratopathy
• Uveitis
• Secondary glaucoma
• UGH syndrome
EVOLUTION AND DEVELOPMENT
Generation-III (1953 – 1975)
Iris supported or iris fixated IOLs
Advantages: It is away from angle structures hence
rate of complications like secondary
glaucoma is less.
Rate of dislocation is less.
Less contact with corneal endothelium
hence lesser damage to it.
•Complications:•Iris chaffing
•Pupillary distortion
•Chronic inflammation
•CME
•Distortion on pupillary dilatation
•Endothelial decompensation
EVOLUTION AND DEVELOPMENT
Why the Iris? Iris is the ”toughest” tissue within the eye
The iris is a resilient tissue.
Pigmented tissue in nature is usually associated with being “tough”
Iris Macroscopic appearance.1. Ciliary zone. It presents series of radial streaks
due to underlying radial blood vessels
2. Pupillary zone. Is relatively smooth and flat.
The Iris consists of Pupil BorderThe sphincter mechanism of the
pupil border is functioning due to a smooth muscle with a great constricting and dilating capacity.
Anatomy of the IrisThe stroma connects to a sphincter muscle (sphincter pupillae)
It contracts the pupil in a circular motion, and a set of dilator muscles (dilator pupillae) which pull the iris radially to enlarge the pupil, pulling it in folds.
Anatomy of the IrisSphicnter pupillae muscle
Dilator pupillae muscle
Pupil Dilatation Mechanism (3 concentric areas)The central part is highly mobile dilatable and constrictable
The paracentral thickened area lies at two-third from the iris base
The iris base is immobile.
Binkhorst’s (1965)-
Iridocapsular Lens
Posterior haptics in capsular bag with anterior
loops removed.
In 1970 Binkhorst and Worst employed a trans-
iridectomy suture for fixation mechanism-
MEDALLION lens.
EVOLUTION AND DEVELOPMENT
EVOLUTION AND DEVELOPMENT
Iris clip lens (Binkhorst) Iris claw lens( Worst)
Discovery of the Iris Claw principle
Using an early model, the Slotted Medallion lens, Jan Worst sometimes observed that some iris tissue was caught in the slot of his lens.
This clasping of iris tissue proved to be a serendipitously discovered new possibility for stable fixation of the IOL.
Once the efficacy of this additional fixation method had been proven in a number of cases additional iris stitching seemed no longer necessary.
Peripheral Iris Supported IOLs
The design was relatively simple
One piece, one material, without additional loops.
The fixation mechanism is based on the enclavation of a fold of iris tissue.
In 1997 an improved vaulted design of the ARTISAN® Aphakia Lens was introduced with a number of new characteristics.
The lens configuration was made vaulted to create distance to the iris
Enclavation was made easier by using a lens with a larger and oval aperture between optic and haptics than the original circular shape.
Worst Iris Claw® IOL (left) ARTISAN®/ Iocare Aphakia IOL
Lens Design“Iris Bridge”
support The fixation points of these
lenses are located in the virtually immobile part of the peripheral iris
The “iris bridges” form a shield and protect the cornea from touching the PMMA haptics of the IOL.
The Iocare /ARTISAN® Aphakia IOL
Since the start of the original design of the Iris Claw lens (1978), the fixation concept of this lens has remained unchanged
Only the lens design has slightly changed in 1997 (vaulted design and oval aperture).
Worst Iris Claw design Vaulted IoCare/ ARTISAN® design
Unrestricted dilatation
The haptics (fixation arms) attach to the midperipheral virtually immobile iris stroma, thus allowing the pupil unrestricted ability to dilate &constrict
Fluorescein angiographic studies by Strobel1 and Izak2 have shown no leakage of the iris vessels at the enclavation sites.
Only a few cases of iris atrophy in the area of the fixation have been reported in the literature
Unrestricted dilatation
Lens Manufacturing
Compression Molding Technology During the compression molding process the molecular
structure of PMMA is enhanced by redistributing the molecules into longer chains, resulting in a much stronger material.
Compression Molding Technology
PMMA before and after compression molding.
Extreme flexibility of the hapticsCompression Molding Technology gives a high
tensile strength, combined with flexibility of the lens haptics. The risk of fracture is minimal.Proprietary Tumbling ProcessThe proprietary tumbling process gives a special surface
treatment to IOLs.An ultra smoothness of the IOL is the result.
Technical SpecificationsLens type: AC/ PC Iris
Fixation (“ Iris Bridge”)Lens material: Perspex-CQ
UVFixation: Mid-Peripheral,Iris Stromal SupportOverall diameter: 8.5 mmBody diameter: 5.4 mm
Technical Specifications
Optic diameter: 5.0 mm
Total height: 0.76 mmWeight: 8mg in air
(20D lens)Sterilisation: Ethylene
oxideAC Depth: 3.3 mmA-constant: 115.0
(Ultrasound)115.7 (Optical)
Powers available: +2.0 D to +30.0 D (1.0 D increments)
+14.5 D to +24.5 D (0.5 D increments).
Versatility AC or PC fixation
Paediatric Aphakia IOL
Lens type: AC Iris Fixation (“Iris bridge”);
Lens material: Perspex-CQ UV;
Overall diameter: 6.5 mm;Body diameter: 4.4 mm;Optic diameter: 4.4 mm;Total height: 0.56 mm;Weight: 8mg in air (20D
lens);- 6.5mm overall size
Benefits The “iris bridge” protects the
endothelium from touching the PMMA
Safe clearance from vital structures (corneal endothelium);
Unrestricted pupil dilatation and constriction (sphincter independent)
Excellent centration; once fixated the lens will not decenter
“vaulted” lens configuration
Iris clip Angle Supported lens
Sclera sutured PC IOL
Safety Excellent,predictable
Angle relatedcomplications
Sutures can erode andrefraction unstable
Outcomes Excellent,predictable
Angle relatedcomplications
Refraction not predictable,lens tilt, hemorrhage andsecondary glaucoma
Clinical History 30+ years Removed from manymarkets
30+ years
Toric option Yes No No
Suturingrequired IOL
No No Yes
Fixation options
Iris Angle Sclera, sulcus, iris
Next Generation of Iris Fixated IOLs
Foldable lens body thus permitting a small incision.
Small incision, 3.2 mmControlled folding and
unfolding Reversible treatment Aspherical edge design Large optical zone
Toric iris clip IOLs
PMMAOptic –PolysiloxaneHaptic-PMMA
Other IndicationsIris fixated Custom-made IOLs include lenses for the
treatment of unique ocular conditions likeColoboma, Diplopia
There are two categories of Custom-made lenses: Iris Reconstruction IOLs (made of coloured & clear PMMA) Pupil Occluder for Diplopia Correction (made of black
PMMA).
Iris fixated Reconstruction IOLs
IOLs with coloured haptics (blue, brown, green or black) are ideal for anterior segment reconstruction when iris damage has occurred or is already congenitally present.
Even large iris colobomata can be covered by the coloured haptic of the IOL.
Pupil Occluder for Correction of DiplopiaAnother application of the iris base Fixation Concept is Pupil
Occlusion in case of intolerable Diplopia due to ocular muscle imbalance.
The Pupil Occluder functions as a cover over the pupil to prevent double images.
Occluder is made of black polycarbonate and covers the pupil completely
Due to the vaulted configuration it can be applied in both phakic and aphakic eyes
8.5mm overall size Pupil Occluder in situ
The main features are:
Minimal risk surgeryThe anatomy of the iris and its specific features allow surgery
with minimal risks. Fixation is performed to the iris periphery.
Pressure free iris fixation
No iris atrophy when the recommended surgical technique is used
indicationsSenile cataract with severe zonular dialysis
Traumatic cataract
Congenital or juvenile cataract with subluxation
Secondary implantation after aphakia.
Contraindications
Recurrent or chronic iritisRubella cataract Retina and optic nerve defects; Corneal distrophy (except in preparation for penetrating
keratoplasty)Acute inflammationSevere iris atrophy Uncontrolled chronic glaucoma
Technique for AC iris fixated iol
Video of AC iris clip IOL
Enclavation Forceps
Enclavation Needle
Foldable Iris clipPerform a mainincision of 3.2 mm Insertion Spatula
How to properly Enclavate the iris
Notice that the “claws” are perfectly aligned.
PROPER technique
WRONG technique
See damage caused by improper enclavation
Peripheral iridectomy or iridotomy
Although all Aphakia IOLs are vaulted ,it is highly recommended to perform an iridectomy or iridotomy.
The pigment layer needs to be perforated completely
An iridectomy or iridotomy has to be made to avoid a postop pupil block
It can also be used to manage an unwanted iris prolapse.
Retropupillary Fixation Technique
As recommended by A. Mohr, M.D.
A technique is recommended with a 12 o’clock frown incision (corneo-scleral 5.5mm)
Authors from Bursa-Turkey use a scleral tunnel incision to avoid the formation of postoperative astigmatism.
The width of the incision should be 5.5 mm.
Do not constrict the pupil
Leave the pupil at a minimum size of approximately 3mm to allow the lens to reach the retropupillary position through the pupil.
use of high viscosity viscoelasticInject a small amount of viscoelastic from the periphery of the
eye, but never directly into the pupillary area
Implantation of the iol
The IOL will be inserted into the anterior chamber with the convex side downwards (upside down) holding it in the forceps.
With a manipulator, the IOL will be brought into the horizontal position from 3 o’clock to 9 o’clock.
iol fixation on the iris
After the IOL has been brought behind the iris and the pupil is constricted, the IOL will be lifted and tilted slightly in order to show the contour of the“claws” through the iris stroma.
A fine spatula is inserted and exerts gentle pressure on the slotted centre of the lens haptic, the “claw”.
The same manoeuvre is now repeated on the other side.
The IOL is now retropupillary fixated.
VIDEO OF RETROFIXTED IRIS CLIP
Peripheral iridectomy
It is not absolutely essential and strictly recommended to perform an iridectomy
removal of all viscoelastic Carefully remove all of the viscoelastic to avoid a high pressure.Suturing Close the incision with sutures.
VIDEO PUPILOPLATY
INTRA operative problems
Macular burnsThe light of the surgical
microscope may cause damage to the macula during surgery
PreventionUse a protecting filter on the
microscope or cover the pupil with a surgical sponge .
Iris Prolapse
An iris prolapse occurs more often when making a corneoscleral incision, than making a tunnel incision
PreventionPlace one or two sutures
after the insertion of the lens and before the enclavation.
SolutionMake an iridectomy as soon
as possible.
Lens not centered properly
A decentered IOL may cause glare or halos
PreventionCheck the centration of the
IOL on the pupil after removal of the viscoelastic.
SolutionIt can be corrected by re-
enclavation
Insufficient Iris Enclavation
Insufficient Iris Enclavation can lead to postoperative dislocation
PreventionUse the specific instruments
developed for the Aphakia IOL implantation
SolutionRe-enclavate a dislocated
IOL
Subluxation
After ocular trauma or spontaneously, luxation of one of the claws can occur, leading to subluxation of the IOL
when a too small amount of iris tissue is enclavated, The IOL has to be reenclavated
immediately to minimize endothelial damage.
Secondary surgical interventions
Lens repositioningIs necessary after lens decentration and in cases in which a
preventive repositioning was performedin subjects with too small amounts of enclavated iris tissue.
Lens replacementAn IOL can be removed and replaced by a new Aphakia IOL.
Articles of Interest
Long-term follow-up of the corneal endothelium after artisan lens implantation for unilateral traumatic and unilateral congenital cataract in children: two case series.
Odenthal MT, Sminia ML, Prick LJ, Gortzak-Moorstein N, Volker -Dieben HJ. Cornea 2006; 25(10):1173-7.
RESULTS: Endothelial cell loss 10.5 yrs after iris fixated IOL implantation for traumatic cataract was substantial & related to the length corneal scar of original trauma . In children operated for congenital cataract , no difference was found in CECD in operated & unoperated eyes after 9.5 yrs after artisan iols
Penetrating keratoplasty combined with posterior Artisan iris-fixated intraocular lens Implantation
Dighiero P, Guigou S, Mercie M, Briat B, Ellies P, Gicquel JJ. Acta Ophthalmol Scand. 2006; 84(2):197-200
Dr Vijay Shetty Dr Suhas Haldipurkar
Dr Shweta Rao Dr Maninder Singh Setia
A RETROSPECTIVE ANALYSIS OF IOL POWER CALCULATION AND
POSTOPERATIVE RESULTS OF IRIS CLIP IOL
WOC 2011 Abu Dhabi
AIM
• To study the post operative visual outcome in retrofixed iris clip IOLs with respect to uncorrected visual acuity and best corrected visual acuity
• To study the refractive outcome in iris clip IOLs using IOL master and various formulae
• To study the prevalance of PXF, Trauma, Marfan’s syndrome, retinal tears, cystoids macular oedema and retinal detachment in patients who underwent iris clip IOL
CONCLUSION
Retrofixed iris clip IOL is a relatively a safe procedure in eyes with no capsular support. Trauma, PXF and Marfan’s syndrome were associated in 41%, 14% and 14% respectively .IOL was required in 5/26 (19%). Similar IOL refixation was noted in both horizontal and vertical fixation.CME: 2/26, Uveitis: 1/27, Retinal Hole: 1/27 in our population,
Hoffer Q formula predicted the IOL power most accurately for iris clip IOLs consistently in eyes with varied axial length followed by Holladay and SRK T.
Books1. Cataract and IOL Daljit Singh, Jan Worst, Ravijit Singh, Indu R. Singh. 1993 Chapter 20: Iris Claw Lens, page 82-972. A Colour Atlas of Lens Implantation Chapter 13: Iris-fixated lenses, evolution and application – Jan
Worst, page 79-873. Iris Claw Lens or Lobster Claw Lens of Worst Alpar JJ / Fechner PV, 1986
Thanks