2.
ICL is made from 100 %
biocompatible
soft flexible gel lens
The material porcine Collagen is
polymerised with HEMA
Hence collagen copolymer = Collamer
Posterior chamber Phakic IOL model
3. History
Fathers of Phakic IOL –
Choyce,Strampelli, Barraquer
conduted first ever trials using AC
refractive lenses to correct high
myopia in 1950s.
But due to unacceptable complications
such as loss of corneal endothelial
cells,iris atrophy, PAS , these
especially the angle supported lenses
were phased out of the market.
4. First model made by Fyodorov in
1980s
in Russia of a collar button
configuration.
First implant in Europe in 1993.
Concept of soft phakic lens.
5.
This material of Collamer was made
by STAAR Visian Surgicals which
provide good biocompatibility ,Optical
capability,
with a lens resting behind the iris in
ciliary sulcus.
6.
7.
8. Prerequisites
Residual bed after LASIK < 250
microns
Initial Corneal thickness < 480 microns
Stable refraction <0.5 D change in
previous
12 months
No ocular pathology
9. 3 variants of Phakic IOL
Angle supported and Iris claw lenses
are the AC variants.
ICL is the PC variant.
Due to reasons of complications
associated with ACIOL design
10. FDA approved its use in Myopia and
Myopic astigmatism in year 2005
via NEI sponsored study.
Indication in
Myopia of -3 to -25 Dioptres
Astigmtism up to – 6 Dioptres
Thin Corneas
11. Measurement of white to white
diameter
Using Orbscan,UBM or calipers
Add 0.5 mm to horizontal WW
measurement for ICL overall length
ICL too short – lens vault
less, exposes to risk of Anterior
capsular cataract
ICL too long – lens vault exceeds –
angle crowding –closed angle
glaucoma
12. Vault:
Ideally should be 500 microns= one
corneal thickness
High vault - Iris chaffing
pigment
dispersion,glaucoma
Low vault - ICL contact with
crystalline
lens – cataract formation.
13. Procedure
Under topical anaesthesia ,0.6 mm
side port , 3.2 mm clear corneal
incision on steep meridian.
Lens introduced into the soft silicone
tip with micro incision injector and
positioned behind iris with help of
blunt spatula.
Lens is implanted temporally and
gently rotated to align the axis with the
cylindrical axis of the patient.
14. Complete removal of viscoelastic
material
Miotic agent injected
Incision closed by hydrating incision
Peripheral iridotomy – intraoperatively
with
vannas scissors ,sufficiently wide,
positioned superiorly , well away from
haptics – to provide outlet for aqueous
flow around lens.
15.
16. Reports
Kamiya et al in a studied the long
term clinical outcomes of implantation
of these implantable lenses for
Myopia in 56 eyes of 34 patients with
refractive errors of
- 4.00 to – 15.25 D .
Kamiya K, Shimizu K . Implantable Collamer lens for hyperopia
after radial keratotomy . J Cataract Refract Surg 2008; 34(8) :
1403-4
17.
They concluded implantation is safe
and effective with predictable and
stable refrative results during a four
year observation period.
18.
Kamiya et al also compared Collamer
toric ICL with wavefront guided LASIK
for high myopic astigmatism and found
that all eyes in ICL group and 71
percent in LASIK were within +/- 1.00
D of targetted SE correction at six
months.
19. Hence it was concluded that these
Toric ICLs were superior compared to
LASIK in all measures of
safety, efficacy predicability,stability.
Thus overall complication rate was
low and patients have good visual
recovery.
20.
According to a study by Sanders et al
,the incidence of anterior subcapsular
opacities and cataracts were studied
after ICL implantation.Approximately 6
– 7 % of eyes developed anterior
subcapsular opacities at over 7 yrs but
1 % progressed to cataract.
Sanders DR. Anterior subcapsular opacities and cataracts 5
years after surgery in the visian collamer lens FDA trial . J
Refract Surg 2008;24(6): 566-70
21.
With the advancements in anterior
segment imaging , ultrasonic
biomicroscopy , Optical coherence
tomography and Scheimpflug imging
,valuable information is now provided
about anterior segment anatomy for
phakic Intraocular lenses(ICL) for
correction of moderate to high
refractive errors.
22. Advantages
The procedure is reversible unlike
LASIK
The quality of vision is usually better
It creates a small corneal incision so
astigmatism is minimum
Corneal tissue is not removed ,hence
adequate tear layer
Reduction of risk of optical distortions
an higher order aberrations